如何將gridview轉換爲excel？

Question

我想將gridview轉換爲excel .xls，但它會拋出錯誤，當我點擊確定後，它會轉換，但整個頁面出現在Excel中。 我想盡一切可能的內容類型，我有Excel 2010中

錯誤：

the file you are trying to convert is in a different format than specified by the file extension

代碼：

protected void btnTransactionDetails_Click(object sender, EventArgs e) 
    { 
     try 
     { 
      LabelResult.Text = ""; 
      //GetReport(); 
      int BusID= Convert.ToInt32(DropDownListBuses.SelectedValue); 
      int AccountID= Convert.ToInt32(DropDownList1.SelectedValue); 
      DateTime FromDate = Convert.ToDateTime(FromDateTextBox.Text); 
      DateTime ToDate = Convert.ToDateTime(ToDateTextBox.Text); 
      DataTable dt= new DataTable(); 
      dt= Activities.GetLedger(AccountID, BusID, FromDate, ToDate); 
      GridViewLedger.DataSource= dt; 
      GridViewLedger.DataBind(); 
      ViewState["Ledger"]= dt; 

     } 
     catch (Exception ex) 
     { 
      LabelResult.Text = ex.Message; 
     } 

    } 

protected void btnExportToExcel_Click(object sender, EventArgs e) 
    { 
     try 
     { 
      Response.Clear(); 
      Response.AddHeader("content-disposition", "attachment;filename=LedgerReport_" + FromDateTextBox.Text + " To " + ToDateTextBox.Text + ".xls"); 
      Response.ContentType = "application/vnd.xlsx"; 
      System.IO.StringWriter stringWrite = new System.IO.StringWriter(); 
      System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite); 

      htmlWrite.Write("<table><tr><td colspan='4'><center>Report Date : " + FromDateTextBox.Text + " To " + FromDateTextBox.Text + "</center></td></tr></table>"); 
      GridViewLedger.AllowPaging = false; 
      GridViewLedger.AllowSorting = false; 
      // showAttendance(); 
      GridViewLedger.DataSource = (DataSet)ViewState["Ledger"]; 
      GridViewLedger.DataBind(); 
      for (int i = 0; i <= GridViewLedger.Columns.Count - 1; i++) 
      { 

       GridViewLedger.HeaderRow.Cells[i].Style.Add("background-color", "#2FA4E7"); 
       GridViewLedger.HeaderRow.Cells[i].Style.Add("color", "#FFFFFF"); 

      } 


      for (int i = 0; i < GridViewLedger.Rows.Count; i++) 
      { 
       GridViewRow row = GridViewLedger.Rows[i]; 

       row.Cells[3].Style.Add("background-color", "#73a839"); 
       row.Cells[3].Style.Add("color", "#FFFFFF"); 

       row.Cells[4].Style.Add("background-color", "#DA272D"); 
       row.Cells[4].Style.Add("color", "#FFFFFF"); 

      } 

      GridViewLedger.RenderControl(htmlWrite); 
      string style = @"<style> .textmode { mso-number-format:\@; } </style>"; 
      Response.Write(style); 
      Response.Write(stringWrite.ToString()); 
      Response.End(); 
     } 
     catch (Exception x) 
     { 
      // ResultLabel.ResultLabelAttributes(x.Message, ProjectUserControls.Enums.ResultLabel_Color.Red); 
     } 
    } 

Answer 1

改變這一行

（數據集）的ViewState [「萊傑「];到（DataTable）ViewState [「Ledger」];

您正試圖強制轉換數據表爲DataSet 你會得到以下異常

無法投型「System.Data.DataTable」的對象鍵入「System.Data.DataSet中」。

因爲的ViewState [「總帳」]包含數據表（已分配數據表的話）

---

我創建了一個示例項目它究竟是你的代碼相同。它的工作精細對我來說請檢查

protected void Page_Load(object sender, EventArgs e) 
    { 
     if (!IsPostBack) 
     { 
      DataTable table = new DataTable(); 
      table.Columns.Add("Dosage", typeof(int)); 
      table.Columns.Add("Drug", typeof(string)); 
      table.Columns.Add("Patient", typeof(string)); 
      table.Columns.Add("Date", typeof(DateTime)); 

      // Here we add five DataRows. 
      table.Rows.Add(25, "Indocin", "David", DateTime.Now); 
      table.Rows.Add(50, "Enebrel", "Sam", DateTime.Now); 
      table.Rows.Add(10, "Hydralazine", "Christoff", DateTime.Now); 
      table.Rows.Add(21, "Combivent", "Janet", DateTime.Now); 
      table.Rows.Add(100, "Dilantin", "Melanie", DateTime.Now); 
      GridView1.DataSource = table; 
      GridView1.DataBind(); 
      ViewState["Ledger"] = table; 
     } 
    } 

    protected void Button1_Click(object sender, EventArgs e) 
    { 
     Response.Clear(); 
     Response.AddHeader("content-disposition", "attachment;filename=LedgerReport.xls"); 
     Response.ContentType = "application/vnd.xls"; 
     System.IO.StringWriter stringWrite = new System.IO.StringWriter(); 
     System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite); 

     htmlWrite.Write("<table><tr><td colspan='4'><center>Report Date </center></td></tr></table>"); 
     GridView1.AllowPaging = false; 
     GridView1.AllowSorting = false; 
     GridView1.DataSource = (DataTable)ViewState["Ledger"]; 
     GridView1.DataBind(); 
     for (int i = 0; i <= GridView1.Columns.Count - 1; i++) 
     { 
      GridView1.HeaderRow.Cells[i].Style.Add("background-color", "#2FA4E7"); 
      GridView1.HeaderRow.Cells[i].Style.Add("color", "#FFFFFF"); 

     } 

     GridView1.RenderControl(htmlWrite); 
     string style = @"<style> .textmode { mso-number-format:\@; } </style>"; 
     Response.Write(style); 
     Response.Write(stringWrite.ToString()); 
     Response.End(); 
    } 
    public override void VerifyRenderingInServerForm(Control control) 
    { 
     /* Confirms that an HtmlForm control is rendered for the specified ASP.NET 
      server control at run time. */ 
    }