从ITemplate内部动态创建的ImageButton中触发RowCommand事件

Question

我有一个基于DropDownList的值的动态创建的GirdView。 我使用了Itemplate接口产生的字段：

public class CreateItemTemplateOrder : ITemplate 
{ 
    ImageButton imgbtn_up; 
    ImageButton imgbtn_down; 

    string s_imgbtn_up_name; 
    string s_imgbtn_up_ImageUrl; 
    string s_imgbtn_up_CommandName; 
    string s_imgbtn_up_CommandArgument; 

    public CreateItemTemplateOrder(string imgbtn_up_name, string imgbtn_up_ImageUrl, string imgbtn_up_CommandName, string imgbtn_up_CommandArgument) 
    { 

     this.s_imgbtn_up_name = imgbtn_up_name; 
     this.s_imgbtn_up_ImageUrl = imgbtn_up_ImageUrl; 
     this.s_imgbtn_up_CommandName = imgbtn_up_CommandName; 
     this.s_imgbtn_up_CommandArgument = imgbtn_up_CommandArgument; 

    } 

    public void InstantiateIn(Control objContainer) 
    { 
     imgbtn_up = new ImageButton(); 
     imgbtn_up.DataBinding += new EventHandler(imgbtn_up_DataBinding); 
     objContainer.Controls.Add(imgbtn_up); 
    } 

    private void imgbtn_up_DataBinding(object sender, EventArgs e) 
    { 
     ImageButton imgbtn_up = (ImageButton)sender; 
     imgbtn_up.ID = s_imgbtn_up_name; 
     imgbtn_up.ImageUrl = s_imgbtn_up_ImageUrl; 
     imgbtn_up.CommandName = s_imgbtn_up_CommandName; 
     imgbtn_up.CommandArgument = s_imgbtn_up_CommandArgument; 
     imgbtn_up.CausesValidation = false; 
    } 
} 

现在我想火RowCommand从命令参数和命令名称此动态生成列一定到这的ImageButton

代码得到这个工作是：

Protected void inizializza_gw_tipi(){ 
     TemplateField order_col = new TemplateField; 
     order_col.ItemTemplate = new CreateItemTemplateOrdine("imgbtn_up", "~/imgs/Up.gif", "minus", "order"); 
     order_col.HeaderText = "order"; 
     order_col.SortExpression = "order"; 

     gw_tipi.Columns.Add(order_col); 
} 

所有这些代码工作正常，但在ImageButton的单击时没有从GridView的火灾RowCommand

编辑： 我调用DropDownList的SelectedIndexChanged事件中的过程ddl_tipi_SelectedIndexChanged（Object sender，System.EventArgs e） inizializza_gw_tipi（）; gw_tipi.DataBind（）; }

Protected Sub inizializza_gw_tipi() 
     Using cn As New SqlConnection(shared_foos.connectionString) 
     Using cmd As New SqlCommand("SELECT nome_tabella, nome_campo_id, nome_campo_nome, nome_campo_descrizione, has_order FROM maschere_tipi WHERE id = @id", cn) 
      cmd.Parameters.AddWithValue("id", IIf(Session("sel_val") Is Nothing, "", Session("sel_val"))) 
      cn.Open() 
      Dim rdr As SqlDataReader = cmd.ExecuteReader 
      rdr.Read() 
      If rdr.HasRows Then 
       Dim b_crea_controllo As Boolean = True 
       'controllo se mettere o no la colonna ordine 
       If rdr("has_order") = True Then 
        'controllo che la colonna non sia già stata inserita, 
        'se è già stata inserita la rimuovo e la ricreo 
        For i As Integer = 0 To gw_tipi.Columns.Count - 1 
         If gw_tipi.Columns(i).HeaderText = "ordine" Then 
          'gw_tipi.Columns.Remove(gw_tipi.Columns(i)) 
          b_crea_controllo = False 
         End If 
        Next 

        If b_crea_controllo = True Then 

         Dim ordine_col As New TemplateField() 
         ordine_col.ItemTemplate = New CreateItemTemplateOrdine("lbl_ordine", "ordine", "imgbtn_up", "~/imgs/Up.gif", "meno", "ordine", "imgbtn_down", "~/imgs/Down.gif", "piu", "ordine", AddressOf ImageCommand) 
         ordine_col.HeaderText = "ordine" 
         ordine_col.SortExpression = rdr("nome_campo_nome") 

         gw_tipi.Columns.Add(ordine_col) 

        End If 
       End If 

       b_crea_controllo = True 

       For i As Integer = 0 To gw_tipi.Columns.Count - 1 
        If gw_tipi.Columns(i).HeaderText = rdr("nome_campo_nome") Then 
         b_crea_controllo = False 
        End If 
       Next 

       If b_crea_controllo = True Then 
        Dim nome_col As New TemplateField() 
        nome_col.ItemTemplate = New CreateItemTemplateLabel("lbl_nome", rdr("nome_campo_nome")) 
        nome_col.HeaderText = rdr("nome_campo_nome") 
        nome_col.SortExpression = rdr("nome_campo_nome") 
        gw_tipi.Columns.Add(nome_col) 
       End If 

       b_crea_controllo = True 

       For i As Integer = 0 To gw_tipi.Columns.Count - 1 
        If gw_tipi.Columns(i).HeaderText = rdr("nome_campo_descrizione") Then 
         b_crea_controllo = False 
        End If 
       Next 

       If b_crea_controllo = True Then 
        Dim descrizione_col As New TemplateField() 
        descrizione_col.ItemTemplate = New CreateItemTemplateLabel("lbl_descrizione", rdr("nome_campo_descrizione")) 
        descrizione_col.HeaderText = rdr("nome_campo_descrizione") 
        descrizione_col.SortExpression = rdr("nome_campo_descrizione") 
        gw_tipi.Columns.Add(descrizione_col) 
       End If 

       Dim str_order_by As String = " ORDER BY " 
       Dim str_ordine As String = "" 

       If rdr("has_order") = True Then 
        str_ordine = ", ordine " 
        str_order_by &= "ordine" 
       Else 
        str_order_by &= rdr("nome_campo_nome") 
       End If 

       Dim sqlds_tipi As New SqlDataSource(shared_foos.connectionString, "SELECT " & rdr("nome_campo_id") & ", " & rdr("nome_campo_nome") & ", " & rdr("nome_campo_descrizione") & str_ordine & " FROM " & rdr("nome_tabella") & str_order_by) 

       gw_tipi.DataSource = sqlds_tipi 

      End If 
     End Using 
    End Using 

End Sub 

Answer 1

我把你的代码原样并测试过。这段代码没有错误。行命令也被正确触发。我认为问题在于你创建的动态gridview的事件绑定。

对于要触发的行命令，必须在每次回发时创建gridview。并且该事件应该受到约束。

您提供的代码并不完全是我所需要的。它没有网格视图的初始化。

以下应该给你一些见解。

GridView GV = new GridView(); //Make sure to create the grid view on every postback and populate it. Alternatively (i dont know if its a good practice.) you can store a reference of gridview in session. 
GV.RowCommand += new GridViewCommandEventHandler(GV_RowCommand); //bind the row command event. this should solve the problem. 

服务器不记录动态创建的控件。所以当回发发生时，gridview控件不存在。因此不会触发任何事件。

Answer 2

我有同样的问题 - 但我的问题是在母版页EnableViewState =“false”。 onrowcommand工作正常后，我设置他的母版页使用EnableViewState =“true”。