麻煩從GridView控件

Question

羣雄，排數

我有以下的GridView：

 <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="SysInvoiceID" DataSourceID="SqlDataSource1"> 
      <Columns> 
       <asp:BoundField DataField="SysInvoiceID" HeaderText="SysInvoiceID" ReadOnly="True" SortExpression="SysInvoiceID" /> 
       <asp:BoundField DataField="BillMonth" HeaderText="BillMonth" SortExpression="BillMonth" /> 
       <asp:BoundField DataField="InvoiceDate" HeaderText="InvoiceDate" ReadOnly="True" SortExpression="InvoiceDate" /> 
       <asp:BoundField DataField="InvoiceNumber" HeaderText="InvoiceNumber" SortExpression="InvoiceNumber" /> 
       <asp:BoundField DataField="Net" HeaderText="Net" SortExpression="Net" /> 
       <asp:BoundField DataField="VAT" HeaderText="VAT" SortExpression="VAT" /> 
       <asp:BoundField DataField="Gross" HeaderText="Gross" SortExpression="Gross" /> 
       <asp:ButtonField CommandName="ViewInvoice" HeaderText=" " ShowHeader="True" Text="View" /> 
      </Columns> 
     </asp:GridView> 

這裏是代碼隱藏頁：

public partial class PagingTest01 : System.Web.UI.Page 
{ 

protected void Page_Load(object sender, EventArgs e) 
{ 

} 

void GridView1_RowCommand(Object sender, GridViewCommandEventArgs e) 
{ 
    // If multiple buttons are used in a GridView control, use the 
    // CommandName property to determine which button was clicked. 
    if (e.CommandName == "ViewInvoice") 
    { 
     // Convert the row index stored in the CommandArgument 
     // property to an Integer. 
     int index = Convert.ToInt32(e.CommandArgument); 

     // Retrieve the row that contains the button clicked 
     // by the user from the Rows collection. 
     GridViewRow row = GridView1.Rows[index]; 
     // Now you have access to the gridviewrow. 

     ViewButton_Click(row); 
    } 
} 




protected void ViewButton_Click(GridViewRow row) 
{ 
    byte[] FileImage = GetImageData(0,row); 

     if (FileImage != null) 
     { 
      base.Response.Clear(); 
      base.Response.Buffer = true; 
      base.Response.ContentType = "Application/x-pdf"; 
      base.Response.ContentEncoding = Encoding.Default; 
      string attachment = string.Format("attachment;filename=\"Invoice_{0}.pdf\"", "Customer1"); 
      base.Response.AddHeader("content-disposition", attachment); 
      base.Response.BinaryWrite(FileImage); 
      base.Response.Flush(); 
      base.Response.Close(); 
      base.Response.End(); 
     } 
} 





public byte[] GetImageData(int sysInvoiceID, GridViewRow row) 
    { 

     string strUserID = CommonCode.GetCurrentUserID().ToString(); 
     string strCustomerID = CommonCode.GetCurrentCustomerID().ToString(); 
     byte[] numArray; 

     string strConnectionString = "Data Source=TESTSERV;Initial Catalog=DB_Invoices;Persist Security Info=True"; 
     SqlConnection connection = new SqlConnection(strConnectionString); 
     SqlCommand command = new SqlCommand("select FileImage from DB_Invoices.dbo.Bills WHERE (FileType = 'PDF' AND SysInvoiceID = @ID)", connection); 
     command.Parameters.AddWithValue("@ID", GridView1.Rows[row].Cells[0].Text); 

     SqlDataAdapter da = new SqlDataAdapter(command); 
     DataSet ds = new DataSet(); 

     try 
     { 
      connection.Open(); 



      da.Fill(ds); 
      DataRow item = ds.Tables[0].Rows[0]; 
      byte[] item1 = (byte[])item["FileImage"]; 
      ds.Tables.Clear(); 
      numArray = item1; 


     } 
     catch (Exception ex) 
     { 
      throw ex; 
     } 
     finally 
     { 
      connection.Close(); 
     } 
     return numArray; 
    } 



} 

所以基本上我有很多行的GridView控件，每一個在其旁邊有一個「查看」按鈕。點擊'View'時，我試圖使用GridView1_RowCommand，它應該在傳遞到ViewButton_Click之前獲取點擊的行。然後這將調用GetImageData並通過行號到該行：

command.Parameters.AddWithValue("@ID", GridView1.Rows[row].Cells[0].Text); 

細胞0是SysInvoiceID列，因此，如果正確的行通過，@ID將被分配一個SysInvoiceID。

然而，'行'似乎並不是一個有效的參數，但我想不出爲什麼不... ...除非我必須明確地將其轉換爲int嗎？任何幫助將非常感激！謝謝。

Answer 1

我剛纔評論這是側面說明但也許這是你的問題，因爲你提到「它似乎並沒有一個有效的說法，但我想不出爲什麼不......除非我必須明確地將其轉換爲int「。

如果ID是int你應該使用int.Parse(celltext)，othwerwise數據庫中獲取了錯誤的類型，因爲AddWithValue需要推斷值的類型。

所以使用：

command.Parameters.AddWithValue("@ID", int.Parse(GridView1.Rows[row].Cells[0].Text)); 

除此之外，您還沒有添加事件處理程序GridView1_RowCommand。

<asp:GridView ID="GridView1" OnRowCommand="GridView1_RowCommand" runat="server" AutoGenerateColumns="False" DataKeyNames="SysInvoiceID" DataSourceID="SqlDataSource1"> 
    .... 

並且您也未將CommandArgument設置爲該行的索引。無論如何，如果您需要行索引，我會使用不同的方法。使用模板字段和控件，例如Button。然後使用它的NamingContainer屬性來獲取參考「GridViewRow`，這裏有一個例子：Get Row Index on Asp.net Rowcommand event

Answer 2

使用本：

int index = ((GridViewRow)((WebControl)sender)).RowIndex; 

到位

int index = Convert.ToInt32(e.CommandArgument);