问题
I know that the wpf-documentviewer supports the searching in the documents, if the document is a xpsdocument. The search only highlights one hit after the other.
Is it possible to highlight all hits through the search-box?
I have the following code to create and set the document of a DocumentViewer-Control:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
FixedDocument fixedDocument = CreateTestDocument();
this.documentViewer.Document = BuildFixedDocumentSequence(fixedDocument);
}
private static FixedDocumentSequence BuildFixedDocumentSequence(FixedDocument fixedDocument)
{
MemoryStream ms = new MemoryStream();
Uri documentUri = new Uri("pack://document.xps");
Package p = Package.Open(ms, FileMode.Create, FileAccess.ReadWrite);
PackageStore.AddPackage(documentUri, p);
XpsDocument xpsDocument = new XpsDocument(p, CompressionOption.NotCompressed, documentUri.AbsoluteUri);
XpsDocumentWriter dw = XpsDocument.CreateXpsDocumentWriter(xpsDocument);
dw.Write(fixedDocument);
FixedDocumentSequence fixedDocumentSequence = xpsDocument.GetFixedDocumentSequence();
if (fixedDocumentSequence == null)
return null;
return fixedDocumentSequence;
}
public FixedDocument CreateTestDocument()
{
FixedDocument document = new FixedDocument();
PrintDialog printDialog = new PrintDialog();
document.DocumentPaginator.PageSize = new Size(printDialog.PrintableAreaWidth, printDialog.PrintableAreaHeight);
AddPage(document, "This is the first page");
AddPage(document, "This is not the first page");
AddPage(document, "This is the third page");
return document;
}
private void AddPage(FixedDocument document, string content)
{
FixedPage page = new FixedPage
{
Width = document.DocumentPaginator.PageSize.Width,
Height = document.DocumentPaginator.PageSize.Height
};
TextBlock pageText = new TextBlock
{
Text = content,
FontSize = 40,
Margin = new Thickness(96)
};
page.Children.Add(pageText);
PageContent pageContent = new PageContent();
((IAddChild)pageContent).AddChild(page);
document.Pages.Add(pageContent);
}
}
The xaml-code consists just of the documentviewer. Now if i type in "page" into the search-box of the documentviewer and press return, the word "page" on the first page is highlighted. Through another time pressing the return-key the word "page" on the second page is highlighted.
What I want to achieve is that by pressing return for the first time, all words "page" are highlighted.
回答1:
There is no easy way of doing this, that I could find. With a lot of trial and error, but mainly reflection (pun intended;), this can be done - I was still quite amazed when it actually worked.
I subclassed the DocumentViewer, and went from there. The http://reflector.webtropy.com site came in very handy, wouldn't have gotten anywhere without the source code.
The code behind didn't change, take it from the question post.
Usage:
<local:MyDocumentViewer x:Name="documentViewer" />
MyDocumentViewer:
/// <summary>
/// DocumentViewer that has his Search Box overridden in order to select multiple results in the document.
/// Use IsMultiSearchEnabled to turn off this behavior.
/// The number of results can be limited with the MaxSearchResults property.
/// </summary>
public class MyDocumentViewer : DocumentViewer
{
private ToolBar _myfindToolbar; // MS.Internal.Documents.FindToolBar
private object _mydocumentScrollInfo; // MS.Internal.Documents.DocumentGrid
private MethodInfo _miFind; // DocumentViewerBase.Find(FindToolBar)
private MethodInfo _miGoToTextBox; // FindToolBar.GoToTextBox()
private MethodInfo _miMakeSelectionVisible; // DocumentGrid.MakeSelectionVisible()
/// <summary>
/// Limit for returned search results. 0 for no limit, default is int.MaxValue.
/// </summary>
public int MaxSearchResults { get { return (int)GetValue(MaxSearchResultsProperty); } set { SetValue(MaxSearchResultsProperty, value); } }
public static readonly DependencyProperty MaxSearchResultsProperty =
DependencyProperty.Register("MaxSearchResults", typeof(int), typeof(MyDocumentViewer), new PropertyMetadata(int.MaxValue));
/// <summary>
/// Determines if the search of the find toolbox is overridden and multiple search results are selected in the document.
/// </summary>
public bool IsMultiSearchEnabled { get { return (bool)GetValue(IsMultiSearchEnabledProperty); } set { SetValue(IsMultiSearchEnabledProperty, value); } }
public static readonly DependencyProperty IsMultiSearchEnabledProperty =
DependencyProperty.Register("IsMultiSearchEnabled", typeof(bool), typeof(MyDocumentViewer), new PropertyMetadata(true));
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
if (IsMultiSearchEnabled)
{
// get some private fields from the base class DocumentViewer
_myfindToolbar = this.GetType().GetPrivateFieldOfBase("_findToolbar").GetValue(this) as ToolBar;
_mydocumentScrollInfo = this.GetType().GetPrivateFieldOfBase("_documentScrollInfo").GetValue(this);
// replace button click handler of find toolbar
EventInfo evt = _myfindToolbar.GetType().GetEvent("FindClicked");
ReflectionHelper.RemoveEventHandler(_myfindToolbar, evt.Name); // remove existing handler
evt.AddEventHandler(_myfindToolbar, new EventHandler(OnFindInvoked)); // attach own handler
// get some methods that will need to be invoked
_miFind = this.GetType().GetMethod("Find", BindingFlags.NonPublic | BindingFlags.Instance);
_miGoToTextBox = _myfindToolbar.GetType().GetMethod("GoToTextBox");
_miMakeSelectionVisible = _mydocumentScrollInfo.GetType().GetMethod("MakeSelectionVisible");
}
}
/// <summary>
/// This is replacing DocumentViewer.OnFindInvoked(object sender, EventArgs e)
/// </summary>
private void OnFindInvoked(object sender, EventArgs e)
{
IList allSegments = null; // collection of text segments
TextRange findResult = null; // could also use object, does not need type
//Give ourselves focus, this ensures that the selection
//will be made visible after it's made.
this.Focus();
// Drill down to the list of selected text segments: DocumentViewer.TextEditor.Selection.TextSegments
object textEditor = this.GetType().GetProperty("TextEditor", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(this); // System.Windows.Documents.TextEditor
object selection = textEditor.GetType().GetProperty("Selection", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(textEditor); // System.Windows.Documents.TextSelection
FieldInfo fiTextSegments = selection.GetType().GetPrivateFieldOfBase("_textSegments");
IList textSegments = fiTextSegments.GetValue(selection) as IList; // List<System.Windows.Documents.TextSegment>
// Clearing the selection in order to start search from the beginning of the document. I suspect there might be a better way of doing this.
object segmentStart = textSegments[0].GetType().GetField("_start", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(textSegments[0]); // get segment start (one textsegment is always present)
int currentOffset = (int)segmentStart.GetType().GetProperty("System.Windows.Documents.ITextPointer.Offset", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(segmentStart); // get offset of segment start
segmentStart = segmentStart.GetType().GetMethod("CreatePointer", new Type[] { segmentStart.GetType(), typeof(int) }).Invoke(segmentStart, new object[] { segmentStart, -currentOffset }); // set the offset back to 0
textSegments[0] = textSegments[0].GetType().GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, new Type[] { segmentStart.GetType(), segmentStart.GetType() }, null)
.Invoke(new object[] { segmentStart, segmentStart}); // create a new textsegment with resetted offset
for (int i = 1; i < textSegments.Count; i++)
{
textSegments.RemoveAt(i); // remove all other segments
}
// Always search down
_myfindToolbar.GetType().GetProperty("SearchUp").SetValue(_myfindToolbar, false);
// Search and collect the find results
int resultCount = 0;
do
{
// invoke: DocumentViewerBase.Find(findToolBar)
findResult = _miFind.Invoke(this, new object[] { _myfindToolbar }) as TextRange;
if (findResult != null)
{
// get the selected TextSegments of the search
textSegments = fiTextSegments.GetValue(selection) as IList; // List<System.Windows.Documents.TextSegment>
if (allSegments == null)
allSegments = textSegments; // first search find, set whole collection
else
allSegments.Add(textSegments[0]); // after first find, add to collection
resultCount++;
}
}
while (findResult != null && (MaxSearchResults == 0 || resultCount < MaxSearchResults)); // stop if no more results were found or limit is exceeded
if (allSegments == null)
{
// alert the user that we did not find anything
string searchText = _myfindToolbar.GetType().GetProperty("SearchText").GetValue(_myfindToolbar) as string;
string messageString = string.Format("Searched the document. Cannot find '{0}'.", searchText);
MessageBox.Show(messageString, "Find", MessageBoxButton.OK, MessageBoxImage.Asterisk);
}
else
{
// set the textsegments field to the collected search results
fiTextSegments.SetValue(selection, allSegments);
// this marks the text. invoke: DocumentGrid.MakeSelectionVisible()
_miMakeSelectionVisible.Invoke(_mydocumentScrollInfo, null);
}
// put the focus back on the findtoolbar textbox to search again. invoke: FindToolBar.GoToTextBox()
_miGoToTextBox.Invoke(_myfindToolbar, null);
}
}
public static class ReflectionExtensions
{
/// <summary>
/// Gets private field of base class. Normally, they are not directly accessible in a GetField call.
/// </summary>
public static FieldInfo GetPrivateFieldOfBase(this Type type, string fieldName)
{
BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.NonPublic;
// Declare variables
FieldInfo fieldInfo = null;
// Search as long as there is a type
while (type != null)
{
// Use reflection
fieldInfo = type.GetField(fieldName, bindingFlags);
// Yes, do we have a field?
if (fieldInfo != null) break;
// Get base class
type = type.BaseType;
}
// Return result
return fieldInfo;
}
}
/// <summary>
/// http://www.codeproject.com/Articles/103542/Removing-Event-Handlers-using-Reflection
/// </summary>
public static class ReflectionHelper
{
static Dictionary<Type, List<FieldInfo>> dicEventFieldInfos = new Dictionary<Type, List<FieldInfo>>();
static BindingFlags AllBindings
{
get { return BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static; }
}
static List<FieldInfo> GetTypeEventFields(Type t)
{
if (dicEventFieldInfos.ContainsKey(t))
return dicEventFieldInfos[t];
List<FieldInfo> lst = new List<FieldInfo>();
BuildEventFields(t, lst);
dicEventFieldInfos.Add(t, lst);
return lst;
}
static void BuildEventFields(Type t, List<FieldInfo> lst)
{
//BindingFlags.FlattenHierarchy only works on protected & public, doesn't work because fields are private
// Uses .GetEvents and then uses .DeclaringType to get the correct ancestor type so that we can get the FieldInfo.
foreach (EventInfo ei in t.GetEvents(AllBindings))
{
Type dt = ei.DeclaringType;
FieldInfo fi = dt.GetField(ei.Name, AllBindings);
if (fi != null)
lst.Add(fi);
}
}
static EventHandlerList GetStaticEventHandlerList(Type t, object obj)
{
MethodInfo mi = t.GetMethod("get_Events", AllBindings);
return (EventHandlerList)mi.Invoke(obj, new object[] { });
}
public static void RemoveAllEventHandlers(object obj) { RemoveEventHandler(obj, ""); }
public static void RemoveEventHandler(object obj, string EventName)
{
if (obj == null)
return;
Type t = obj.GetType();
List<FieldInfo> event_fields = GetTypeEventFields(t);
EventHandlerList static_event_handlers = null;
foreach (FieldInfo fi in event_fields)
{
if (EventName != "" && string.Compare(EventName, fi.Name, true) != 0)
continue;
// STATIC Events have to be treated differently from INSTANCE Events...
if (fi.IsStatic)
{
if (static_event_handlers == null)
static_event_handlers = GetStaticEventHandlerList(t, obj);
object idx = fi.GetValue(obj);
Delegate eh = static_event_handlers[idx];
if (eh == null)
continue;
Delegate[] dels = eh.GetInvocationList();
if (dels == null)
continue;
EventInfo ei = t.GetEvent(fi.Name, AllBindings);
foreach (Delegate del in dels)
ei.RemoveEventHandler(obj, del);
}
else
{
EventInfo ei = t.GetEvent(fi.Name, AllBindings);
if (ei != null)
{
object val = fi.GetValue(obj);
Delegate mdel = (val as Delegate);
if (mdel != null)
{
foreach (Delegate del in mdel.GetInvocationList())
ei.RemoveEventHandler(obj, del);
}
}
}
}
}
}
来源：https://stackoverflow.com/questions/15292203/highlight-all-hits-in-documentviewer