Comment exporter gridview vers Excel dans ASP.net en utilisant C#?

Question

Est-ce que quelqu'un sait comment exporter un gridview dans ASP.net vers Excel ??

J'utilise ce code, mais je ne peux pas accéder à mon gridview parce qu'il est nul

protected void BtnExport_Click(object sender, EventArgs e) 
{ 
    DataTable dtOriginal = new DataTable(); 
    dtOriginal = (DataTable)gvRapporten.DataSource; //Return Table consisting data 

    //Create Tempory Table 
    DataTable dtTemp = new DataTable(); 

    //Creating Header Row 
    dtTemp.Columns.Add("<b>Melder</b>"); 
    dtTemp.Columns.Add("<b>Onderwerp</b>"); 
    dtTemp.Columns.Add("<b>Oplosser</b>"); 
    dtTemp.Columns.Add("<b>Niveau 2</b>"); 
    DataRow drAddItem; 
    for (int i = 0; i < dtOriginal.Rows.Count; i++) 
    { 
     drAddItem = dtTemp.NewRow(); 
     drAddItem[0] = dtOriginal.Rows[i][0].ToString();//Melder 
     drAddItem[1] = dtOriginal.Rows[i][1].ToString();//Onderwerp 
     drAddItem[2] = dtOriginal.Rows[i][2].ToString();//Oplosser 
     drAddItem[3] = dtOriginal.Rows[i][3].ToString();//Niveau 2 

     dtTemp.Rows.Add(drAddItem); 
    } 

    //Temp Grid 
    DataGrid dg = new DataGrid(); 
    dg.DataSource = dtTemp; 
    dg.DataBind(); 
    ExportToExcel("Report.xls", dg); 
    dg = null; 
    dg.Dispose(); 
} 

private void ExportToExcel(string strFileName, DataGrid dg) 
{ 
    Response.ClearContent(); 
    Response.AddHeader("content-disposition", "attachment; filename=" + strFileName); 
    Response.ContentType = "application/excel"; 
    System.IO.StringWriter sw = new System.IO.StringWriter(); 
    HtmlTextWriter htw = new HtmlTextWriter(sw); 
    dg.RenderControl(htw); 
    Response.Write(sw.ToString()); 
    Response.End(); 
} 

Answer 1

pouvez-vous essayer?

System.IO.StringWriter sw = new System.IO.StringWriter(); 
HtmlTextWriter htw = new HtmlTextWriter(sw); 
Response.AddHeader("content-disposition", "attachment; filename=" + strFileName); 
Response.ClearContent(); 

Response.AddHeader("content-disposition", attachment); 

dg.RenderControl(htw); 
Response.Write(sw.ToString()); 
Response.Flush(); 
Response.End(); 

Answer 2

code Vous génère simplement une Html-table (qui est ce que ASP.Net rend un GridView/DataGrid) et rien autre. Excel peut gérer cela et l'afficher comme une Table mais ce n'est pas vraiment un fichier xls - ou csv.

La propriété DataSource d'un GridView est toujours null/nothing après la publication. Vous devez générer à nouveau DataSource avant de l'exporter vers Excel.

Ce code convertit tout datatable à un csv-String:

C#

public static string tableToCsv(DataTable DT) 
{ 
    System.Text.StringBuilder csv = new System.Text.StringBuilder(); 
    System.Text.StringBuilder rowData = new System.Text.StringBuilder(); 
    DataRow DR = null; 
    DataColumn DC = null; 

    foreach (DataColumn DC_loopVariable in DT.Columns) { 
     DC = DC_loopVariable; 
     rowData.Length = 0; 
     rowData.Append((rowData.Length > 0 ? ";" : "").ToString()); 
     rowData.Append(DC.ColumnName); 
    } 
    csv.Append(rowData.ToString()).Append(Strings.Chr(13)); 

    foreach (DataRow DR_loopVariable in DT.Rows) { 
     DR = DR_loopVariable; 
     rowData.Length = 0; 

     foreach (DataColumn DC_loopVariable in DT.Columns) { 
      DC = DC_loopVariable; 
      rowData.Append((rowData.Length > 0 ? ";" : "").ToString()); 
      rowData.Append(DR[DC.ColumnName].ToString()); 
     } 
     csv.Append(rowData.ToString()).Append(Strings.Chr(13)); 
    } 
    return csv.ToString(); 
} 

VB

Public Shared Function tableToCsv(ByVal DT As DataTable) As String 
    Dim csv As New System.Text.StringBuilder 
    Dim rowData As New System.Text.StringBuilder 
    Dim DR As DataRow 
    Dim DC As DataColumn 

    For Each DC In DT.Columns 
     rowData.Length = 0 
     rowData.Append(IIf(rowData.Length > 0, ";", "").ToString) 
     rowData.Append(DC.ColumnName) 
    Next 
    csv.Append(rowData.ToString).Append(Chr(13)) 

    For Each DR In DT.Rows 
     rowData.Length = 0 

     For Each DC In DT.Columns 
      rowData.Append(IIf(rowData.Length > 0, ";", "").ToString) 
      rowData.Append(DR.Item(DC.ColumnName).ToString) 
     Next 
     csv.Append(rowData.ToString).Append(Chr(13)) 
    Next 
    Return csv.ToString 
End Function 

Answer 3

Dim dt As DataTable = ViewState("FinalState") 
Dim GV As New GridView 
GV.DataSource = dt ' UpdateDataTable(ViewState("FinalTable")) 
GV.DataBind() 
Response.Clear() 
Response.Buffer = True 
Response.AddHeader("content-disposition", "attachment;filename=ProspectsBank.xls") 
Response.Charset = "" 
Response.ContentType = "application/vnd.ms-excel" 
Dim sw As New StringWriter() 
Dim hw As New HtmlTextWriter(sw) 
For i As Integer = 0 To GV.Rows.Count - 1 
    'Apply text style to each Row 
    GV.Rows(i).Attributes.Add("class", "textmode") 
Next 
GV.RenderControl(hw) 
Dim style As String = "<style> .textmode { mso-number-format:\@; } </style>" 
Response.Write(style) 
Response.Output.Write(sw.ToString()) 
clsLog.SaveLogValue(Request.ServerVariables("REMOTE_ADDR"), "SearchAudienceForMagazine.aspx", "User Export Data From Our Databank in EXCEL format. Current they Exported " & dt.Rows.Count & " Data.", Session("User_TypeId"), Session("User_Name")) 
Response.Flush() 
Response.End()