问题
What is the fastest way to export DataGridView rows in the range of 460328 - 800328 to Excel or into an SQL Server database table with out using Microsoft office interop as interop is quite slow and heavy on system resources?
回答1:
For exporting to Excel, if you aren't using the XML based 2007 or 2010, Interop is pretty much the only way to go. It's not as bad as it's reputation though. I'll list a few solutions.
1 To Excel
First add a Microsoft.Office.Interop.Excel component reference to your project. This should be under the .NET tab in Project -> Add Reference. add the using statement to your form:
using Excel = Microsoft.Office.Interop.Excel;
add a button control, and add this code to it's body:
private void btnExport_Click(object sender, EventArgs e)
{
Excel.Application app = new Excel.Application();
app.Visible = true;
Excel.Workbook wb = app.Workbooks.Add(1);
Excel.Worksheet ws = (Excel.Worksheet)wb.Worksheets[1];
// changing the name of active sheet
ws.Name = "Exported from gridview";
ws.Rows.HorizontalAlignment = HorizontalAlignment.Center;
// storing header part in Excel
for (int i = 1; i < dataGridView1.Columns.Count + 1; i++)
{
ws.Cells[1, i] = dataGridView1.Columns[i - 1].HeaderText;
}
// storing Each row and column value to excel sheet
for (int i = 0; i < dataGridView1.Rows.Count - 1; i++)
{
for (int j = 0; j < dataGridView1.Columns.Count; j++)
{
ws.Cells[i + 2, j + 1] = dataGridView1.Rows[i].Cells[j].Value.ToString();
}
}
// sizing the columns
ws.Cells.EntireColumn.AutoFit();
// save the application
wb.SaveAs("c:\\output.xls",Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive , Type.Missing, Type.Missing, Type.Missing, Type.Missing);
// Exit from the application
app.Quit();
}
}
2 - to SQL Server
This requires no interop. For ease of use, pass your List object to the event executing the inserts. If you have tables set up to correspond to your grid view column, it's easy. Here, I use a sproc.
private void btnToSQL_Click(object sender, EventArgs e)
{
string connStr = @"Data Source=(local)\sqlexpress;Initial Catalog=rTALIS;Integrated Security=True";
var cn = new SqlConnection(connStr);
var cm = new SqlCommand("exec usp_InsertRecord", cn);
cm.CommandType = System.Data.CommandType.StoredProcedure;
try
{
cn.Open();
foreach (Row r in rows)
{
cm.Parameters.Clear();
cm.Parameters.AddWithValue("@Number1", r.Number1);
cm.Parameters.AddWithValue("@Number2", r.Number2);
cm.Parameters.AddWithValue("@Number3", r.Number3);
cm.Parameters.AddWithValue("@Number4", r.Number4);
cm.Parameters.AddWithValue("@Number5", r.Number5);
cm.Parameters.AddWithValue("@Number6", r.Number6);
cm.Parameters.AddWithValue("@Number7", r.Number7);
cm.Parameters.AddWithValue("@Date1", r.Date1);
cm.ExecuteNonQuery();
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
cn.Close();
}
}
Let me know if I need to tweak this for you. In the original example, I had List rows = new List(); declared in the form_Load method. This worked for that solution, but it's scope is now too limited. I have moved it up/out into the class, so that in can be called anywhere on the form (specifically btnToSQL_Click). I have commented it out below:
List<Row> rows = new List<Row>();
private void Form1_Load(object sender, EventArgs e)
{
//var rows = new List<Row>(); //limited scope
var sr = new StreamReader(@"C:\so_test.txt");
while (!sr.EndOfStream)
{
string s = sr.ReadLine();
if (!String.IsNullOrEmpty(s.Trim()))
{
rows.Add(new Row(s));
}
}
sr.Close();
dataGridView1.DataSource = rows;
}
回答2:
For transferring to Excel, this is the fastest method that I've found (although it does use Office InterOp). Loop through each cell in the DataGridView and assign it to an array of objects. Then assign the entire array to an Excel Range. This is much faster than assigning a value to each Excel cell individually because it only invokes InterOp once. Pardon the VB:
Sub Export()
Dim xlApp As New Excel.Application
Dim wb As Excel.Workbook = xlApp.Workbooks.Add
Dim ws As Excel.Worksheet = wb.Worksheets(1)
Dim dgv as DataGridView = MyDataGridView
Dim ExportArray(dgv.Rows.Count, dgv.Columns.Count - 1) As Object
Dim j, i As Integer
For j = 0 To dgv.Columns.Count - 1
ExportArray(0, j) = dgv.Columns(j).Name
For i = 1 To dgv.Rows.Count
ExportArray(i, j) = dgv(j, i - 1).Value
Next
Next
Dim col As String = ColNumtoLetter(j)
ws.Range("A1:" & col & i).Value = ExportArray
End Sub
Private Function ColNumtoLetter(ByVal iCol As Integer) As String
Dim Result As String = ""
Dim iAlpha As Integer = Int(iCol / 26.001)
Dim iRemainder As Integer = iCol - (iAlpha * 26)
If iAlpha > 0 Then
Result = Chr(iAlpha + 64)
End If
If iRemainder > 0 Then
Result = Result & Chr(iRemainder + 64)
End If
Return Result
End Function
The second method just translates the final column number to the corresponding Excel column name.
See "Fast Exporting from DataSet to Excel" and "Export Data to Excel Much Faster" for more info.
回答3:
Check out Create Excel files from C# without office as this refers to using EPPlus which works very well - I was able to create my CSV data from the data table and the bulk load in memory the Excel file to stream out. Simply a few lines of code. Varible csvData is string value of all your csvData.
using( ExcelPackage pck = new ExcelPackage( ) )
{
//Create the worksheet
ExcelWorksheet ws = pck.Workbook.Worksheets.Add( "Sheet1" );
// set the delimiter
etf.Delimiter = ',';
etf.EOL = "\n";
etf.TextQualifier = "\"";
//Load the datatable into the sheet, starting from cell A1. Print the column names on row 1
ws.Cells["A1"].LoadFromText( csvData, etf );
return pck.GetAsByteArray( );
}
回答4:
One option would be to write data to a CSV file instead of an Excel file. Excel would have no problem reading it afterwards.
If you're not familiar, in CSV (i.e. Comma Separated) files the fields are separated by commas and rows are separated by newlines (\n or \r\n).
Something like (may not compile!):
private void WriteData() {
using (var file = System.IO.StreamWriter(@"C:\Path\To\File.csv")) {
foreach (var row in dataGrid.Rows) {
foreach (var cell in row.Cells) {
// Note that if some cells contain commas,
// you'd need to wrap them in quotes.
file.Write(cell.Value).Write(",");
}
}
file.Write("\n");
}
}
For faster performance, it may also be a good idea collect a few hundred (or thousand) rows into a single string and then write it to a file, instead of writing cell-by-cell.
回答5:
Here I used DataTable to write data to excel file. I think data Grid View also same to the DataTable.
First get data from Database:
db.GetData(sqlgetprint);
It's call for method that method is:
class DataBaseConnection
{
private OdbcConnection conn1 = new OdbcConnection(@"FILEDSN=C:/OTPub/Ot.dsn;" + "Uid=sa;" + "Pwd=otdata@123;"); //"DSN=Ot_DataODBC;" + "Uid=sa;" + "Pwd=otdata@123;"
//select
public System.Data.DataTable GetData(string sql)
{
try
{
conn1.Open();
OdbcDataAdapter adpt = new OdbcDataAdapter(sql, conn1);
DataTable dt = new DataTable();
adpt.Fill(dt);
conn1.Close();
return dt;
}
catch (Exception ex)
{
conn1.Close();
throw ex;
}
}
}
After that create Object for DataBaseConncetion Class in your working form
DataBaseConnection db = new DataBaseConnection();
In your Button Click Event you can Write this Code to Write to the Excel file
string sqlgetprint = "SELECT Service_No,Full_name, Acc_No, OP_date, On_time, Off_time, OP_hours, Payment FROM Print_Op ORDER BY Service_No , OP_date";
DataTable dtall = db.GetData(sqlgetprint);
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.Filter = "Excel Documents (*.xls)|*.xls";
saveFileDialog1.FileName = "Employee Details.xls";
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
string fname = saveFileDialog1.FileName;
StreamWriter wr = new StreamWriter(fname);
for (int i = 0; i < dtall.Columns.Count; i++)
{
wr.Write(dtall.Columns[i].ToString().ToUpper() + "\t");
}
wr.WriteLine();
//write rows to excel file
for (int i = 0; i < (dtall.Rows.Count); i++)
{
for (int j = 0; j < dtall.Columns.Count; j++)
{
if (dtall.Rows[i][j] != null)
{
wr.Write(Convert.ToString(dtall.Rows[i][j]) + "\t");
}
else
{
wr.Write("\t");
}
}
//go to next line
wr.WriteLine();
}
//close file
wr.Close();
if (File.Exists(fname))
{
System.Diagnostics.Process.Start(fname);
}
}
}
catch (Exception)
{
MessageBox.Show("Error Create Excel Sheet!");
}
回答6:
This may be faster way,
using Excel = Microsoft.Office.Interop.Excel;
public static void SaveGridToExcel(DataGridView DGV)
{
if (DGV.Rows.Count > 0)
{
string filename = "";
SaveFileDialog SV = new SaveFileDialog();
SV.Filter = "EXCEL FILES|*.xlsx;*.xls";
DialogResult result = SV.ShowDialog();
if (result == DialogResult.OK)
{
filename = SV.FileName;
bool multiselect = DGV.MultiSelect;
DGV.MultiSelect = true;
DGV.SelectAll();
DGV.ClipboardCopyMode = DataGridViewClipboardCopyMode.EnableAlwaysIncludeHeaderText;
Clipboard.SetDataObject(DGV.GetClipboardContent());
var results = System.Convert.ToString(Clipboard.GetData(DataFormats.Text));
DGV.ClearSelection();
DGV.MultiSelect = multiselect;
Microsoft.Office.Interop.Excel.Application XCELAPP = null;
Microsoft.Office.Interop.Excel.Workbook XWORKBOOK = null;
Microsoft.Office.Interop.Excel.Worksheet XSHEET = null;
object misValue = System.Reflection.Missing.Value;
XCELAPP = new Excel.Application();
XWORKBOOK = XCELAPP.Workbooks.Add(misValue);
XCELAPP.DisplayAlerts = false;
XCELAPP.Visible = false;
XSHEET = XWORKBOOK.ActiveSheet;
XSHEET.Paste();
XWORKBOOK.SaveAs(filename, Excel.XlFileFormat.xlOpenXMLWorkbook);
XWORKBOOK.Close(false);
XCELAPP.Quit();
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(XSHEET);
System.Runtime.InteropServices.Marshal.ReleaseComObject(XWORKBOOK);
System.Runtime.InteropServices.Marshal.ReleaseComObject(XCELAPP);
}
catch { }
}
}
}
来源：https://stackoverflow.com/questions/11742446/what-is-the-fastest-way-to-export-datagridview-rows-to-excel-or-into-an-sql-serv