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  2. Export Excel chart to SVG creates an empty file

Export Excel chart to SVG creates an empty file

由 旧时模样 提交于 2021-02-16 07:15:53

问题


I am trying to export an Excel chart in SVG format using VBA.

    Set objChrt = ActiveChart.Parent
    objChrt.Activate
    Set curChart = objChrt.Chart
    
    curChart.Export fileName:=fileName, FilterName:="SVG"

If I replace "SVG" by "PNG", the export works exactly as intended and produces a valid PNG file. However, "SVG" results in an empty file. (Manually, there is an option to save as SVG inside Excel 365, so the export filter exists).

According to the documentation, Filtername is "The language-independent name of the graphic filter as it appears in the registry.", but I couldn't find anything like that in the registry, and either way, it's hard to imagine the SVG filtername being named anything other than "SVG".

Is there a way to export a Chart in SVG format using VBA?

Note: There is another question about Chart.export producing an empty file, and the fix was to use ChartObject.Activate before the export. This question is different because the code works correctly with "PNG" but fails with "SVG" (so it's not an issue related to activation or visibility). Also the recommended fix does not work.


回答1:


Exporting to .svg without any external applications using only Excel and VBA

I had to create a new answer because there wasn't enough space in my other one. Personally, I would prefer to use this solution, as there are no external dependencies.

I can now confidently answer this question: Is there a way to export a Chart in SVG format using VBA?

Yes.

It's a hacky mess but it works for now... at least on my machine.

And I tried to create a simple interface for the code so you don't really have to understand it to use it. Still, first I will explain how it works, what problems exist that had to be overcome, and how I managed to solve them. Then, I give a short and simple usage example and instructions. So if you are not interested in the technicalities, you can skip to the easy part.

What's the idea?

The code basically tries to just use the manual export method. There are several problems with this, the first being yet another bug in the Chart.Export method. Chart.Export Interactive:=True is supposed to open the desired dialog box, but this just doesn't work. By leveraging rarely used and even undocumented shortcuts (Probably not, but I had to find one of them with the brute force method), the export window can be opened very reliably using SendKeys "+{F10}" followed by SendKeys "g". The first hurdle is taken, but the trouble has only just begun!

It turns out, that opening a modal Dialog stops all code execution in the Workbook. No, not only in the Workbook, in the entire Application. Even if we call code in another application instance before we open the dialog, how can we keep it running there and return at the same time to finish opening the dialog? It sounds impossible because VBA is strictly single-threaded...

Well, it turns out, the single threading is not quite so strict :) The solution is called Application.OnTime, which starts a procedure at a predetermined time in the future. That procedure has to run in a different instance of Excel.Application because Application.OnTime will only start a procedure if the application is in certain modes (Ready, Copy, Cut, or Find), and having VBA code running or having a modal dialog open are certainly not among those. Therefore, before the dialog is opened, we have to create a background instance of the Excel app, insert VBA code into it and call that code, which will then schedule other code to start running in the background instance once the dialog is open. Note: Because we want to insert the code automatically into the background instance, we need to enable Trust access to the VBA project object model.

The next question is: How can we work with the Windows dialog box using only VBA code? I tried very hard to avoid more SendKeys but unfortunately, some problems were just out of my league. I managed to get all the window and control handles of the dialog via EnumChildWindows and used the information to insert text into the "FileName" ComboBox. Since you can also insert the path there, the only problems left were selecting ".svg" in the FileFormat ComboBox and clicking the "Save" Button.

Changing the selection in the Combobox is relatively easy using Windows API functions but the problem is to actually get it to register the change. It appeared to have changed in the dialog but when I clicked "Save" it still saved as .png. I spent hours in Spy++ monitoring the messages that are sent during a manual change but I wasn't able to reproduce them with VBA. The language is truly horrible for low-level tasks, trying to align bits with VBA is a pain. Anyways, because of this, it had to be SendKeys again for changing the file format and pressing 'Save'.

I tried to be very careful with the SendKeys usage, implementing various safety checks, and pulling the target window to the front before every usage, but you can never be 100% safe with it.

Because the method requires a background instance of an app once again, I implemented a class for a ShapeExporter object again. Creating the object opens the background app, destroying the object closes it.

Simple usage guide

The following procedure will export all ChartObjects in the specified worksheet to the folder the workbook is saved in.

Sub ExportEmbeddedChartToSVG()
    Dim MyWorksheet As Worksheet
    Set MyWorksheet = Application.Worksheets("MyWorksheet")
    
    'Creating the ShapeExporter object
    Dim oShapeExporter As cShapeExporter
    Set oShapeExporter = New cShapeExporter
    
    'Export as many shapes as you want here, before destroying oShapeExporter
    Dim oChart As ChartObject
    For Each oChart In MyWorksheet.ChartObjects
        'the .ExportShapeAsSVG method of the object takes three arguments:
        '1. The Chart or Shape to be exported
        '2. The target filename
        '3. The target path
        oShapeExporter.ExportShapeAsSVG oChart, oChart.Name, ThisWorkbook.Path
    Next oChart
    
    'When the object goes out of scope, its terminate procedure is automatically called
    'and the background app is closed
    Set oShapeExporter = Nothing
End Sub

For the code to work, you must first:

  1. Trust access to the VBA project object model (for reason see detailed description of the macro)
  2. Create a class module, rename it to "cShapeExporter", and paste the following code into it:
'Class for automatic exporting in SVG-Format
'Initial author: Guido Witt-Dörring, 09.12.2020
'https://stackoverflow.com/a/65212838/12287457

'Note:
'When objects created from this class are not properly destroyed, an invisible 
'background instance of Excel will keep running on your computer. In this 
'case, you can just close it via the Task Manager.
'For example, this will happen when your code hits an 'End' statement, which 
'immediately stops all code execution, or when an unhandled error forces 
'you to stop code execution manually while an instance of this class exists.

Option Explicit

#If VBA7 Then
    Private Declare PtrSafe Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
    Private Declare PtrSafe Function SetForegroundWindow Lib "user32" (ByVal hWnd As LongPtr) As Boolean
    Private Declare PtrSafe Function IsWindowVisible Lib "user32" (ByVal hWnd As LongPtr) As Boolean
    Private Declare PtrSafe Function IsIconic Lib "user32" (ByVal hWnd As LongPtr) As Boolean
    Private Declare PtrSafe Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As LongPtr
#Else
    Private Declare Sub Sleep Lib "kernel32" (ByVal lngMilliSeconds As Long)
    Private Declare Function SetForegroundWindow Lib "user32" (ByVal hwnd As Long) As Boolean
    Private Declare Function IsWindowVisible Lib "User32" (ByVal hWnd As Long) As Boolean
    Private Declare Function IsIconic Lib "User32" Alias "IsIconic" (ByVal hWnd As long) As boolean
    Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
#End If

Private NewXlAppInstance As Excel.Application
Private xlWbInOtherInstance As Workbook
    
Private Sub Class_Initialize()
    Set NewXlAppInstance = New Excel.Application
    Set xlWbInOtherInstance = NewXlAppInstance.Workbooks.Add
    
    NewXlAppInstance.Visible = False
    
    On Error Resume Next
    xlWbInOtherInstance.VBProject.References.AddFromFile "scrrun.dll"
    xlWbInOtherInstance.VBProject.References.AddFromFile "FM20.dll"
    On Error GoTo 0
    
    Dim VbaModuleForOtherInstance As VBComponent
    Set VbaModuleForOtherInstance = xlWbInOtherInstance.VBProject.VBComponents.Add(vbext_ct_StdModule)
    
    VbaModuleForOtherInstance.CodeModule.AddFromString CreateCodeForOtherXlInstance
End Sub

Private Sub Class_Terminate()
    NewXlAppInstance.DisplayAlerts = False
    NewXlAppInstance.Quit
    Set xlWbInOtherInstance = Nothing
    Set NewXlAppInstance = Nothing
End Sub

Public Sub ExportShapeAsSVG(xlShp As Object, FileName As String, FilePath As String)
    'Check if path exists:
    If Not ExistsPath(FilePath) Then
        If vbYes = MsgBox("Warning, you are trying to export a file to a path that doesn't exist! Continue exporting to default path? " & vbNewLine & "Klick no to resume macro without exporting or cancel to debug.", vbYesNoCancel, "Warning") Then
            FilePath = ""
        ElseIf vbNo Then
            Exit Sub
        ElseIf vbCancel Then
            Error 76
        End If
    End If
    If TypeName(xlShp) = "ChartObject" Or TypeName(xlShp) = "Shape" Or TypeName(xlShp) = "Chart" Or TypeName(xlShp) = "ChartArea" Then
        'fine
    Else
        MsgBox "Exporting Objects of type " & TypeName(xlShp) & " not supported, sorry."
        Exit Sub
    End If
    
    If TypeName(xlShp) = "ChartArea" Then Set xlShp = xlShp.Parent
    
retry:
    SetForegroundWindow FindWindow("XLMAIN", ThisWorkbook.Name & " - Excel")
    
    If Not Application.Visible Then 'Interestingly, API function "IsWindowVisible(Application.hWnd)" doesn't work here! (maybe because of multi monitor setup?)
        MsgBox "The workbook must be visible for the svg-export to proceed! It must be at least in window mode!"
        Application.WindowState = xlNormal
        Application.Visible = True
        Sleep 100
        GoTo retry
    End If
    
    If IsIconic(Application.hWnd) Then 'Interestingly "Application.WindowState = xlMinimized" doesn't work here!"
        MsgBox "The workbook can't be minimized for the svg-export to proceed! It must be at least in window mode!"
        Application.WindowState = xlNormal
        Sleep 100
        GoTo retry
    End If
    
    'check if background instance still exists and start support proc
    On Error GoTo errHand
    NewXlAppInstance.Run "ScheduleSvgExportHelperProcess", Application.hWnd, ThisWorkbook.Name, FileName, FilePath
    On Error GoTo 0
    
    Sleep 100

    xlShp.Activate
    
    SetForegroundWindow FindWindow("XLMAIN", ThisWorkbook.Name & " - Excel")
    SendKeys "+{F10}"
    DoEvents
    SendKeys "g"
    DoEvents
    Exit Sub
errHand:
    MsgBox "Error in ShapeExporter Object. No more shapes can be exported."
    Err.Raise Err.Number
End Sub

Public Function ExistsPath(ByVal FilePath As String) As Boolean
    Dim oFso As Object
    Dim oFolder As Object
    
    Set oFso = CreateObject("Scripting.FileSystemObject")
    'Setting the Folder of the Filepath
    On Error GoTo PathNotFound
    Set oFolder = oFso.GetFolder(Left(Replace(FilePath & "\", "\\", "\"), Len(Replace(FilePath & "\", "\\", "\")) - 1))
    On Error GoTo 0
    
    ExistsPath = True
    Exit Function
    
PathNotFound:
    ExistsPath = False
End Function

Private Function CreateCodeForOtherXlInstance() As String
    Dim s As String
    s = s & "Option Explicit" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "#If VBA7 Then" & vbCrLf
    s = s & "    Public Declare PtrSafe Sub Sleep Lib ""kernel32"" (ByVal dwMilliseconds As Long)" & vbCrLf
    s = s & "    Private Declare PtrSafe Function GetForegroundWindow Lib ""user32"" () As LongPtr" & vbCrLf
    s = s & "    Private Declare PtrSafe Function GetWindowText Lib ""user32"" Alias ""GetWindowTextA"" (ByVal hWnd As LongPtr, ByVal lpString As String, ByVal cch As Long) As Long" & vbCrLf
    s = s & "    Private Declare PtrSafe Function FindWindow Lib ""user32"" Alias ""FindWindowA"" (ByVal lpClassName As String, ByVal lpWindowName As String) As LongPtr" & vbCrLf
    s = s & "    Private Declare PtrSafe Function SetForegroundWindow Lib ""user32"" (ByVal hWnd As LongPtr) As Boolean" & vbCrLf
    s = s & "    Private Declare PtrSafe Function SendMessage Lib ""user32"" Alias ""SendMessageA"" (ByVal hWnd As LongPtr, ByVal wMsg As Long, ByVal wParam As LongPtr, lParam As Any) As LongPtr" & vbCrLf
    s = s & "    Private Declare PtrSafe Function GetClassName Lib ""user32"" Alias ""GetClassNameA"" (ByVal hWnd As LongPtr, ByVal lpStr As String, ByVal nMaxCount As Long) As Long" & vbCrLf
    s = s & "    Private Declare PtrSafe Function EnumChildWindows Lib ""user32"" (ByVal hWndParent As LongPtr, ByVal lpEnumFunc As LongPtr, ByVal lParam As LongPtr) As Boolean" & vbCrLf
    s = s & "    Private Declare PtrSafe Function GetWindowTextLength Lib ""user32"" Alias ""GetWindowTextLengthA"" (ByVal hWnd As LongPtr) As Long" & vbCrLf
    s = s & "    Private Declare PtrSafe Function GetWindowLongPtr Lib ""user32"" Alias ""GetWindowLongPtrA"" (ByVal hWnd As LongPtr, ByVal nindex As Long) As LongPtr" & vbCrLf
    s = s & "#Else" & vbCrLf
    s = s & "    Public Declare Sub Sleep Lib ""kernel32"" (ByVal lngMilliSeconds As Long)" & vbCrLf
    s = s & "    Private Declare Function GetForegroundWindow Lib ""user32"" () As Long" & vbCrLf
    s = s & "    Private Declare Function GetWindowText Lib ""user32"" Alias ""GetWindowTextA"" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long" & vbCrLf
    s = s & "    Private Declare Function FindWindow Lib ""user32"" Alias ""FindWindowA"" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long" & vbCrLf
    s = s & "    Private Declare Function SetForegroundWindow Lib ""user32"" (ByVal hwnd As Long) As Boolean" & vbCrLf
    s = s & "    Private Declare Function SendMessage Lib ""user32"" Alias ""SendMessageA"" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long" & vbCrLf
    s = s & "    Private Declare Function GetClassName Lib ""user32"" Alias ""GetClassNameA"" (ByVal hwnd As Long, ByVal lpStr As String, ByVal nMaxCount As Long) As Long" & vbCrLf
    s = s & "    Private Declare Function EnumChildWindows Lib ""User32"" (ByVal hwndParent As Long, ByVal lpEnumFunc As Long, ByVal lParam As Long) As boolean" & vbCrLf
    s = s & "    Private Declare Function GetWindowTextLength Lib ""User32"" Alias ""GetWindowTextLengthA"" (ByVal hwnd As Long) As Long" & vbCrLf
    s = s & "    Private Declare Function GetWindowLongPtr Lib ""User32"" Alias ""GetWindowLongPtrA"" (ByVal hwnd As Long, ByVal nindex As Long) As Long" & vbCrLf
    s = s & "#End If" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "Private Const GWL_ID = -12" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "Private Const WM_SETTEXT = &HC" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "'Const for this Application:" & vbCrLf
    s = s & "Private Const dc_Hwnd = 1" & vbCrLf
    s = s & "Private Const dc_ClassName = 2" & vbCrLf
    s = s & "Private Const dc_CtlID = 3" & vbCrLf
    s = s & "Private Const dc_CtlText = 4" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "Private Const Window_Search_Timeout As Single = 5#" & vbCrLf
    s = s & "Public ChildWindowsPropDict As Object" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "#If VBA7 Then" & vbCrLf
    s = s & "    Private Function GetCtlText(ByVal hctl As LongPtr) As String" & vbCrLf
    s = s & "#Else" & vbCrLf
    s = s & "    Private Function GetCtlText(ByVal hctl As Long) As String" & vbCrLf
    s = s & "#End If" & vbCrLf
    s = s & "    Dim ControlText As String" & vbCrLf
    s = s & " On Error GoTo WindowTextTooLarge" & vbCrLf
    s = s & "    ControlText = Space(GetWindowTextLength(hctl) + 1)" & vbCrLf
    s = s & "    GetWindowText hctl, ControlText, Len(ControlText)" & vbCrLf
    s = s & "    GetCtlText = ControlText 'Controls Text" & vbCrLf
    s = s & "    Exit Function" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "WindowTextTooLarge:" & vbCrLf
    s = s & "    ControlText = Space(256)" & vbCrLf
    s = s & "    On Error GoTo -1" & vbCrLf
    s = s & "    GetWindowText hctl, ControlText, Len(ControlText)" & vbCrLf
    s = s & "    GetCtlText = ControlText  'Controls Text" & vbCrLf
    s = s & "End Function" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "#If VBA7 Then" & vbCrLf
    s = s & "    Private Function EnumChildProc(ByVal hWnd As LongPtr, ByVal lParam As LongPtr) As Long" & vbCrLf
    s = s & "#Else" & vbCrLf
    s = s & "    Private Function EnumChildProc(ByVal hWnd As Long, ByVal lParam As Long) As Long" & vbCrLf
    s = s & "#End If" & vbCrLf
    s = s & "    Dim ClassName As String" & vbCrLf
    s = s & "    Dim subCtlProp(1 To 4) As Variant" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    subCtlProp(dc_Hwnd) = hWnd 'Controls Handle" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    ClassName = Space(256)" & vbCrLf
    s = s & "    GetClassName hWnd, ClassName, Len(ClassName)" & vbCrLf
    s = s & "    subCtlProp(dc_ClassName) = Trim(CStr(ClassName)) 'Controls ClassName" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    subCtlProp(dc_CtlID) = GetWindowLongPtr(hWnd, GWL_ID) 'Controls ID" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    subCtlProp(dc_CtlText) = GetCtlText(hWnd)   'Controls Text 'Doesn't always work for some reason..." & vbCrLf
    s = s & "                                                '(sometimes returns """" when Spy++ finds a string)" & vbCrLf
    s = s & "    ChildWindowsPropDict.Add key:=CStr(hWnd), Item:=subCtlProp" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    'continue to enumerate (0 would stop it)" & vbCrLf
    s = s & "    EnumChildProc = 1" & vbCrLf
    s = s & "End Function" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "#If VBA7 Then" & vbCrLf
    s = s & "    Private Sub WriteChildWindowsPropDict(hWnd As LongPtr)" & vbCrLf
    s = s & "#Else" & vbCrLf
    s = s & "    Private Sub WriteChildWindowsPropDict(hWnd As Long)" & vbCrLf
    s = s & "#End If" & vbCrLf
    s = s & "    On Error Resume Next" & vbCrLf
    s = s & "    Set ChildWindowsPropDict = Nothing" & vbCrLf
    s = s & "    On Error GoTo 0" & vbCrLf
    s = s & "    Set ChildWindowsPropDict = CreateObject(""Scripting.Dictionary"")" & vbCrLf
    s = s & "    EnumChildWindows hWnd, AddressOf EnumChildProc, ByVal 0&" & vbCrLf
    s = s & "End Sub" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "Private Function ExistsFileInPath(ByVal FileName As String, ByVal FilePath As String, Optional warn As Boolean = False) As Boolean" & vbCrLf
    s = s & "    Dim oFso As Object" & vbCrLf
    s = s & "    Dim oFile As Object" & vbCrLf
    s = s & "    Dim oFolder As Object" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    Set oFso = CreateObject(""Scripting.FileSystemObject"")" & vbCrLf
    s = s & "    'Setting the Folder of the Filepath" & vbCrLf
    s = s & "    On Error GoTo PathNotFound" & vbCrLf
    s = s & "    Set oFolder = oFso.GetFolder(Left(Replace(FilePath & ""\"", ""\\"", ""\""), Len(Replace(FilePath & ""\"", ""\\"", ""\"")) - 1))" & vbCrLf
    s = s & "    On Error GoTo 0" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    'Writing all Filenames of the Files in the Folder to flStr" & vbCrLf
    s = s & "    For Each oFile In oFolder.Files" & vbCrLf
    s = s & "        If oFile.Name = FileName Then" & vbCrLf
    s = s & "            ExistsFileInPath = True" & vbCrLf
    s = s & "            Exit Function" & vbCrLf
    s = s & "        End If" & vbCrLf
    s = s & "    Next oFile" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    ExistsFileInPath = False" & vbCrLf
    s = s & "    Exit Function" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "PathNotFound:" & vbCrLf
    s = s & "    If warn Then MsgBox ""The path "" & Chr(10) & FilePath & Chr(10) & "" was not found by the function ExistsFileInPath."" & Chr(10) & ""Returning FALSE""" & vbCrLf
    s = s & "    ExistsFileInPath = False" & vbCrLf
    s = s & "End Function" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "#If VBA7 Then" & vbCrLf
    s = s & "    Public Sub ScheduleSvgExportHelperProcess(ByVal Wb1hwnd As LongPtr, ByVal Wb1Name As String, ByVal SvgFileName As String, ByVal SvgFilePath As String)" & vbCrLf
    s = s & "#Else" & vbCrLf
    s = s & "    Public Sub ScheduleSvgExportHelperProcess(ByVal Wb1hwnd As Long, ByVal Wb1Name As String, ByVal SvgFileName As String, ByVal SvgFilePath As String)" & vbCrLf
    s = s & "#End If" & vbCrLf
    s = s & "    If Not Wb1hwnd = FindWindow(""XLMAIN"", Wb1Name & "" - Excel"") Then" & vbCrLf
    s = s & "        MsgBox ""Error finding Wb1hwnd - something unforseen happened!""" & vbCrLf
    s = s & "        GoTo badExit" & vbCrLf
    s = s & "    End If" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    Application.OnTime Now + TimeValue(""00:00:02""), ""'SvgExportHelperProcess """""" & CStr(Wb1hwnd) & """""", """""" & Wb1Name & """""", """""" & SvgFileName _" & vbCrLf
    s = s & "                        & """""", """""" & SvgFilePath & """"""'"", Now + TimeValue(""00:00:015"")" & vbCrLf
    s = s & "    Exit Sub" & vbCrLf
    s = s & "badExit:" & vbCrLf
    s = s & "    MsgBox ""Shutting down background instance of excel.""" & vbCrLf
    s = s & "    Application.DisplayAlerts = False" & vbCrLf
    s = s & "    Application.Quit" & vbCrLf
    s = s & "End Sub" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "Public Sub SvgExportHelperProcess(ByVal Wb1hwndStr As String, ByVal Wb1Name As String, ByVal SvgFileName As String, ByVal SvgFilePath As String)" & vbCrLf
    s = s & "    #If VBA7 And Win64 Then" & vbCrLf
    s = s & "        Dim Wb1hwnd As LongPtr" & vbCrLf
    s = s & "        Wb1hwnd = CLngPtr(Wb1hwndStr)" & vbCrLf
    s = s & "        Dim dlgHwnd As LongPtr" & vbCrLf
    s = s & "        Dim tempHctrl As LongPtr" & vbCrLf
    s = s & "    #Else" & vbCrLf
    s = s & "        Dim Wb1hwnd As LongPtr" & vbCrLf
    s = s & "        Wb1hwnd = CLng(Wb1hwndStr)" & vbCrLf
    s = s & "        Dim dlgHwnd As Long" & vbCrLf
    s = s & "        Dim tempHctrl As Long" & vbCrLf
    s = s & "    #End If" & vbCrLf
    s = s & "    Dim i As Long" & vbCrLf
    s = s & "    Dim stopTime As Single" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    'Find dialog window handle" & vbCrLf
    s = s & "    stopTime = Timer() + Window_Search_Timeout" & vbCrLf
    s = s & "    Do" & vbCrLf
    s = s & "        dlgHwnd = 0" & vbCrLf
    s = s & "        Sleep 15" & vbCrLf
    s = s & "        DoEvents" & vbCrLf
    s = s & "        SetForegroundWindow Wb1hwnd  'FindWindow(""XLMAIN"", Wb1Name & "" - Excel"")" & vbCrLf
    s = s & "        Sleep 150" & vbCrLf
    s = s & "        dlgHwnd = FindWindow(""#32770"", vbNullString)" & vbCrLf
    s = s & "    Loop Until Timer() > stopTime Or dlgHwnd <> 0" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    If dlgHwnd = 0 Then" & vbCrLf
    s = s & "        MsgBox ""Couldn't find dialog window handle!""" & vbCrLf
    s = s & "        GoTo errHand" & vbCrLf
    s = s & "    End If" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    'Enumerate the child windows of the dialog and write their properties to a dictionary" & vbCrLf
    s = s & "    WriteChildWindowsPropDict dlgHwnd" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "    'the first window of class ""Edit"" inside ChildWindowsPropDict will be the filename box" & vbCrLf
    s = s & "    Dim v As Variant" & vbCrLf
    s = s & "    For Each v In ChildWindowsPropDict.items" & vbCrLf
    s = s & "        If Left(CStr(v(dc_ClassName)), Len(CStr(v(dc_ClassName))) - 1) = ""Edit"" Then" & vbCrLf
    s = s & "            tempHctrl = v(dc_Hwnd)" & vbCrLf
    s = s & "            'send message" & vbCrLf
    s = s & "            SendMessage tempHctrl, WM_SETTEXT, 0&, ByVal SvgFilePath & ""\"" & SvgFileName" & vbCrLf
    s = s & "            'we don't need this hwnd anymore" & vbCrLf
    s = s & "            ChildWindowsPropDict.Remove CStr(v(dc_Hwnd))" & vbCrLf
    s = s & "            Exit For" & vbCrLf
    s = s & "        End If" & vbCrLf
    s = s & "    Next v" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "retry:" & vbCrLf
    s = s & "    SetForegroundWindow dlgHwnd" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    SendKeys ""{TAB}""" & vbCrLf
    s = s & "    Sleep 250" & vbCrLf
    s = s & "    SetForegroundWindow dlgHwnd" & vbCrLf
    s = s & "    For i = 1 To 10" & vbCrLf
    s = s & "        SendKeys ""{DOWN}""" & vbCrLf
    s = s & "        Sleep 100" & vbCrLf
    s = s & "        SetForegroundWindow dlgHwnd" & vbCrLf
    s = s & "    Next i" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    SendKeys ""~""" & vbCrLf
    s = s & "    Sleep 100" & vbCrLf
    s = s & "    SetForegroundWindow dlgHwnd" & vbCrLf
    s = s & "    SendKeys ""~""" & vbCrLf
    s = s & "    Sleep 50" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    'give the keystrokes time to process" & vbCrLf
    s = s & "    Sleep 300" & vbCrLf
    s = s & "" & vbCrLf
    s = s & "    'Wait until the file appears in the specified path:" & vbCrLf
    s = s & "    Dim cleanFileName As String" & vbCrLf
    s = s & "    If InStr(1, Right(SvgFileName, 4), "".svg"", vbTextCompare) = 0 Then" & vbCrLf
    s = s & "        cleanFileName = SvgFileName & "".svg""" & vbCrLf
    s = s & "    Else" & vbCrLf
    s = s & "        cleanFileName = SvgFileName" & vbCrLf
    s = s & "    End If" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    Dim retryTime As Single" & vbCrLf
    s = s & "    retryTime = Timer + 5" & vbCrLf
    s = s & "    stopTime = Timer + 60  '1 minute timeout." & vbCrLf
    s = s & "                            'relatively long in case a file already exists dialog appears..." & vbCrLf
    s = s & "    Do Until ExistsFileInPath(SvgFileName, SvgFilePath, False)" & vbCrLf
    s = s & "        Sleep 700" & vbCrLf
    s = s & "        DoEvents" & vbCrLf
    s = s & "        If Timer > retryTime Then" & vbCrLf
    s = s & "            'check if graphic export dialog is top window" & vbCrLf
    s = s & "            If dlgHwnd = GetForegroundWindow Then GoTo retry" & vbCrLf
    s = s & "        End If" & vbCrLf
    s = s & "        If Timer > stopTime Then GoTo timeoutHand" & vbCrLf
    s = s & "    Loop" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "    Exit Sub" & vbCrLf
    s = s & "errHand:" & vbCrLf
    s = s & "    MsgBox ""Error in the helper process""" & vbCrLf
    s = s & "    GoTo badExit" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "timeoutHand:" & vbCrLf
    s = s & "    MsgBox ""Timeout. It seems like something went wrong creating the file. File "" & cleanFileName & "" didn't appear in folder "" & SvgFilePath & "".""" & vbCrLf
    s = s & "    GoTo badExit" & vbCrLf
    s = s & "    " & vbCrLf
    s = s & "badExit:" & vbCrLf
    s = s & "    MsgBox ""Shutting down background instance of excel.""" & vbCrLf
    s = s & "    Application.DisplayAlerts = False" & vbCrLf
    s = s & "    Application.Quit" & vbCrLf
    s = s & "End Sub" & vbCrLf
    s = s & "" & vbCrLf
    CreateCodeForOtherXlInstance = s
End Function



回答2:


Exporting in vector format:

If your main issue is exporting the charts in some vector format, I recommend just exporting as PDF, as this is very easy:

Set curChart = objChrt.Chart
objChrt.ExportAsFixedFormat xlTypePDF, "YourChart"

The PDF now contains your chart as a vector graphic and PDF is a widely supported format for further processing.

If you absolutely need to convert the chart to .svg you can do so from the command line (and therefore easily automatable) using the open-source software Inkscape or so I thought :/.

Converting to SVG:

Unfortunately, the Inkscape conversion didn't seem to work for me so I implemented it using the open-source pdf rendering toolkit Poppler. (Install instructions at the bottom of this post)

This library provides the command line utility pdftocairo, which will be used in the following solution:

Sub ExportChartToSVG()
    Dim MyChart As ChartObject
    Set MyChart = Tabelle1.ChartObjects("Chart 1")
    
    Dim fileName As String
    fileName = "TestExport"

    Dim pathStr As String
    pathStr = ThisWorkbook.Path
    
    ' Export chart as .pdf
    MyChart.Chart.ExportAsFixedFormat Type:=xlTypePDF, FileName:=pathStr & "\" & fileName
   
    ' Convert .pdf file to .svg
    Dim ret As Double
    ret = Shell("cmd.exe /k cd /d """ & pathStr & """ & " & "pdftocairo -svg -f 1 -l 1 " & fileName & ".pdf", vbHide)
End Sub

Note that the text in the resulting .svg file isn't selectable and the file is larger than the file generated by manual export (241 KB vs. 88 KB in my test). The file is definitely infinite resolution, so not that weird bitmap embedded in a .svg file one occasionally sees but comes with another little problem:

Unfortunately, the ExportAsFixedFormat method creates a PDF 'page' where the graphic is positioned on the page depending on the position on the worksheet. The .svg conversion unfortunately keeps this 'page' format. I had to learn that getting rid of this problem is not as simple as I initially thought because excel does not support custom page sizes and therefore exporting a chart as .pdf without white borders seems pretty much impossible, see this bountied but unsolved question (Edit: I solved it in the following part and also posted my method as answer to that question). I tried several methods they didn't even think of in this linked question and still didn't manage to get it done properly using only Excel, it might be possible depending on your printer drivers but I'm not going that way...

Exporting to clean SVG without the white bars:

The easiest workaround is to just use Word to properly export the chart as .pdf:

Sub ExportChartToSVG()
    Dim MyWorksheet As Worksheet
    Set MyWorksheet = Tabelle1
    
    Dim MyChart As ChartObject
    Set MyChart = MyWorksheet.ChartObjects(1)
    
    Dim fileName  As String
    fileName = "TestExport"
    
    Dim pathStr As String
    pathStr = ThisWorkbook.Path
    
    'Creating a new Word Document
    'this is necessary because Excel doesn't support custom pagesizes
    'when exporting as pdf and therefore unavoidably creates white borders around the
    'chart when exporting
    Dim wdApp As Object
    Set wdApp = CreateObject("Word.Application")
    wdApp.Visible = False
    
    Dim wdDoc As Object
    Set wdDoc = wdApp.Documents.Add
    
    MyChart.Copy
    wdDoc.Range.Paste
    
    Dim shp As Object
    Set shp = wdDoc.Shapes(1)
    
    With wdDoc.PageSetup
        .LeftMargin = 0
        .RightMargin = 0
        .TopMargin = 0
        .BottomMargin = 0
        .PageWidth = shp.Width
        .PageHeight = shp.Height
    End With
    shp.Top = 0
    shp.Left = 0
    
    wdDoc.saveas2 fileName:=pathStr & "\" & fileName, FileFormat:=17  '(wdExportFormatPDF)
    wdApp.Quit 0 '(wdDoNotSaveChanges)
    Set wdApp = Nothing
    Set wdDoc = Nothing
    Set shp = Nothing

    ' Convert .pdf file to .svg
    Dim ret As Double
    ret = Shell("cmd.exe /k cd /d """ & pathStr & """ & " & "pdftocairo -svg -f 1 -l 1 " & fileName & ".pdf", vbHide)
End Sub

The resulting .pdf and .svg look exactly the same as the manually exported .svg, with only the .pdf having selectable text. The .pdf file remains in the folder. If necessary, it can easily be deleted later via VBA code...

If this method is used to export a larger number of charts, I strongly recommend moving it into a class and having the class hold an instance of the Word application, so it doesn't constantly reopen and close Word. It has the added benefit of making the actual code to export very terse and clean.

Class-based method for exporting to clean SVG:

The code for exporting becomes very simple:

Sub ExportChartToSVG()
    Dim MyWorksheet As Worksheet
    Set MyWorksheet = Tabelle1
    
    Dim MyChart As ChartObject
    Set MyChart = MyWorksheet.ChartObjects(1)
    
    Dim fileName  As String
    fileName = "TestExport"
    
    Dim filePath As String
    filePath = ThisWorkbook.Path
    
    Dim oShapeExporter As cShapeExporter
    Set oShapeExporter = New cShapeExporter
    
    ' Export as many shapes as you want here, before destroying oShapeExporter
    ' cShapeExporter can export objets of types Shape, ChartObject or ChartArea
    oShapeExporter.ExportShapeAsSVG MyChart, fileName, filePath

    Set oShapeExporter = Nothing
End Sub

Code for class module called cShapeExporter:

Option Explicit

Dim wdApp As Object
Dim wdDoc As Object
Dim wdWasOpen As Boolean

Private Sub Class_Initialize()
    If WordIsRunning Then
        Set wdApp = GetObject(, "Word.Application")
        wdWasOpen = True
    Else
        Set wdApp = CreateObject("Word.Application")
        wdApp.Visible = False
        wdWasOpen = False
    End If
    
    Set wdDoc = wdApp.Documents.Add
    
    With wdDoc.PageSetup
        .LeftMargin = 0
        .RightMargin = 0
        .TopMargin = 0
        .BottomMargin = 0
    End With
End Sub

Private Sub Class_Terminate()
    If Not wdWasOpen Then
        wdApp.Quit 0 '(wdDoNotSaveChanges)
    Else
        wdDoc.Close 0
    End If
    Set wdApp = Nothing
    Set wdDoc = Nothing
End Sub

Public Sub ExportShapeAsSVG(xlShp As Object, fileName As String, filePath As String)
    If TypeName(xlShp) = "ChartObject" Or TypeName(xlShp) = "Shape" Or TypeName(xlShp) = "ChartArea" Then
        'fine
    Else
        MsgBox "Exporting Objects of type " & TypeName(xlShp) & " not supported, sorry."
        Exit Sub
    End If
    
    xlShp.Copy
    wdDoc.Range.Paste
    
    Dim wdShp As Object
    Set wdShp = wdDoc.Shapes(1)
    
    With wdDoc.PageSetup
        .PageWidth = wdShp.Width
        .PageHeight = wdShp.Height
    End With
    
    wdShp.Top = 0
    wdShp.Left = 0
    
    ' Export as .pdf
    wdDoc.saveas2 fileName:=filePath & "\" & fileName, FileFormat:=17  '(wdExportFormatPDF)
    
    ' Convert .pdf file to .svg
    Dim ret As Double
    ret = Shell("cmd.exe /k cd /d """ & filePath & """ & " & "pdftocairo -svg -f 1 -l 1 " & fileName & ".pdf", vbHide)
    
    ' Delete temporary shape in wdDoc
    wdShp.Delete
End Sub

Private Function WordIsRunning() As Boolean
    Dim wdApp As Object
    On Error Resume Next
    Err.Clear
    Set wdApp = GetObject(, "Word.Application")
    If Err.Number <> 0 Then
        WordIsRunning = False
    Else
        WordIsRunning = True
    End If
End Function

Installing the Poppler utility:

I'm assuming you are using Windows here, on Linux getting Poppler is trivial anyway...

So on Windows, I'd suggest installing it using the chocolatey packet manager for Windows. To install chocolatey, you can follow these instructions (takes <5 min).

When you have chocolatey, you can install Poppler with the simple command

choco install poppler

and you are ready to run the code I proposed for converting .pdf to .svg.

If you prefer installing Poppler in a different way, there are various options described here, but I'd like to add some notes about some of the methods:

  1. Downloading the binaries didn't work for me, running the utility would always result in errors.
  2. Installing via Anaconda (conda install -c conda-forge poppler) somehow didn't work for me either. The installation just failed.
  3. Installing via the Windows Subsystem for Linux did work, and the utility worked too, but if you don't already have wsl including a distribution installed you will have to download and install several hundred MB ob data which might be overkill.
  4. If you have MiKTeX installed, the utility is supposed to be included (and was in my case). I tried the utility from my MiKTeX install, and somehow it didn't work.



回答3:


If you don't need .svg in particular then .emf is another vector format. It does not work directly from Excel but it does work using a 'helper' PowerPoint app:

Sub ExportChartToEMF(ByVal ch As Chart, ByVal filePath As String)
    Const methodName As String = "ExportChartToEMF"
    Const ppShapeFormatEMF As Long = 5
    '
    If ch Is Nothing Then Err.Raise 91, methodName, "Chart not set"
    '
    Dim pp As Object
    Dim slide As Object
    Dim errNumber As Long
    '
    Set pp = CreateObject("PowerPoint.Application")
    With pp.Presentations.Add(msoFalse) 'False so it's not Visible
        Set slide = .Slides.AddSlide(.Slides.Count + 1, .Designs(1).SlideMaster.CustomLayouts(1))
    End With
    '
    ch.Parent.Copy
    On Error Resume Next
    slide.Shapes.Paste.Export filePath, ppShapeFormatEMF
    errNumber = Err.Number
    On Error GoTo 0
    '
    pp.Quit
    If Err.Number <> 0 Then Err.Raise Err.Number, methodName, "Error while exporting to file"
End Sub

You would use it like:

ExportChartToEMF ActiveChart, "[FolderPath]\[FileName].emf"

If you really need .svg then unfortunately the functionality is not exposed to VBA although it works manually in Excel and PowerPoint via the Save as Picture dialog (right-click on chart shape).

In short, you cannot fully automate the export of chart to .svg file unless you go through an intermediate format (like .emf or .pdf) or manually saving to .svg via the Save as Picture dialog.



来源：https://stackoverflow.com/questions/65131924/export-excel-chart-to-svg-creates-an-empty-file

标签
excel
vba
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