按下按钮后动态创建的表单消失

Question

我在 PlaceHolder 控件中动态创建了表单，该控件位于 InsertItemTemplate 的 FormView 中。我有一个按钮，在该按钮上可以看到 FOrmView 内的单击表单，并且在表单内我有一个用于插入的按钮。如果我单击插入按钮，在后面的代码中动态创建的表单部分将消失。

这是asp页面中的代码：

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">

   <asp:Button ID="btnShowForm" runat="server" BackColor="#336699" Font-Names="Arial" Font-Size="9pt" ForeColor="White" Text="Show Form" Width="160px"/>

   <br>

   <asp:FormView ID="FV" runat="server" DefaultMode="Edit" Width="100%">

   <InsertItemTemplate>

         <table style="width:60%; border: 1px solid black; border-collapse: collapse;">

         <asp:PlaceHolder ID="plControlUnos" runat="server" />

         <tr>
         <td style="height:30px; text-align:center;" colspan="7">

         <asp:Button ID="save" runat="server"  BackColor="#336699" Font-Names="Arial" Font-Size="9pt" ForeColor="White" Text="Insert" Width="140px" CommandName="insert"/> 
         <asp:Button ID="cancel" runat="server"  BackColor="#336699" Font-Names="Arial" Font-Size="9pt" ForeColor="White" Text="Cancel" Width="140px" CommandName="cancel"/>  

         </td>
         </tr>
        </table>

</InsertItemTemplate>

</asp:FormView>

</asp:Content>

这是创建表单的其他部分并放入 PlaceHolder 的方法：

Sub BindData()

Dim strConnString As String = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString
Dim con As New SqlConnection(strConnString)
Dim cmd As New SqlCommand()

cmd.CommandType = CommandType.Text
cmd.CommandText = "SELECT NAZIV, NAZIV_POLJA FROM PR;" & _
"SELECT NAZIV, NAZIV_POLJA FROM PP"

cmd.Connection = con

Using sda As New SqlDataAdapter()
    cmd.Connection = con
    sda.SelectCommand = cmd

    Using ds As New DataSet

        Try
            con.Open()
            sda.Fill(ds)
   Dim holder As PlaceHolder = CType(FV.FindControl("plControlUnos"), PlaceHolder)

   For Each Row As DataRow In ds.Tables(0).Rows


                holder.Controls.Add(New LiteralControl("<tr style='border: 1px solid black; height:30px;'>"))
                holder.Controls.Add(New LiteralControl("<td style='padding-right:40px; width:400px; text-align:right; background-color:lightgray;border: 1px solid black;'><b>"))

                holder.Controls.Add(New LiteralControl(Row(columnName:="Naziv")))

                holder.Controls.Add(New LiteralControl("</b></td>"))
                holder.Controls.Add(New LiteralControl("<td style='width:300px; text-align:center; background-color:lightgray;border: 1px solid black;'>"))

                Dim txtNOV As New TextBox()
                txtNOV.ID = "txtNOV_" + Row(columnName:="NAZIV_POLJA") + "_KOMADA"
                txtNOV.CssClass = "txtFormat"
                holder.Controls.Add(txtNOV)

                holder.Controls.Add(New LiteralControl("</td>"))
                holder.Controls.Add(New LiteralControl("<td style='width:300px; text-align:center; background-color:lightgray;border: 1px solid black;'>"))

                Dim txtNOV_SUM As New TextBox()
                txtNOV_SUM.ID = "txtNOV_" + Row(columnName:="NAZIV_POLJA") + "_KOMADA_sum"
                txtNOV_SUM.CssClass = "txtFormat"
                txtNOV_SUM.Enabled = False
                holder.Controls.Add(txtNOV_SUM)

                holder.Controls.Add(New LiteralControl("</td>"))
                holder.Controls.Add(New LiteralControl("</tr>"))

    Next

            holder.Controls.Add(New LiteralControl("<tr style='border: 1px solid black; height:30px;'>"))
            holder.Controls.Add(New LiteralControl("<td colspan='2' style='text-align:center; background-color:lightgray;border: 1px solid black;'><b>UKUPNO NOVČANICE</b></td>"))
            holder.Controls.Add(New LiteralControl("<td style='width:300px; text-align:center; background-color:lightgray;border: 1px solid black;'>"))

            Dim txtNOV_KOMADA As New TextBox()
            txtNOV_KOMADA.ID = "txtNOV_KOMADA"
            txtNOV_KOMADA.CssClass = "txtFormat"
            txtNOV_KOMADA.Enabled = False
            holder.Controls.Add(txtNOV_KOMADA)

            holder.Controls.Add(New LiteralControl("</td>"))
            holder.Controls.Add(New LiteralControl("<td style='width:300px; text-align:center; background-color:lightgray;border: 1px solid black;'>"))

            Dim txtNOV_KOMADA_sum As New TextBox()
            txtNOV_KOMADA_sum.ID = "txtNOV_KOMADA_sum"
            txtNOV_KOMADA_sum.CssClass = "txtFormat"
            txtNOV_KOMADA_sum.Enabled = False
            holder.Controls.Add(txtNOV_KOMADA_sum)

            holder.Controls.Add(New LiteralControl("</td>"))
            holder.Controls.Add(New LiteralControl("</tr>"))

            holder.Controls.Add(New LiteralControl("<tr style='border: 1px solid black; height:25px;'>"))
            holder.Controls.Add(New LiteralControl("<td rowspan='9' style='width:100px; text-align:center; background-color:lightgray;border: 1px solid black;' ><b>B)</b></td>" & _
                                                   "<td colspan='3' style='padding-left:40px;width:100px; text-align:left; background-color:lightgray;border: 1px solid black;'><b>Kovani novac</b></td>" & _
                                                   "</tr>"))
        Catch ex As Exception
            Response.Write("Error:" & ex.ToString)
        Finally
            cmd.Parameters.Clear()
            con.Close()
        End Try

    End Using
End Using
End Sub

这是点击我的表单的按钮：

Protected Sub btnShowForm_Click(sender As Object, e As EventArgs) Handles btnShowForm.Click

If IsPostBack Then

    FV.Visible = True
    FV.ChangeMode(FormViewMode.Insert)
    BindData()

End If

End Sub

这是我的表单中的按钮（插入），点击表单消失：

 Protected Sub FV_ItemCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.FormViewCommandEventArgs) Handles FV.ItemCommand

 If e.CommandName = "insert" Then

 Then

 End Sub

我需要做些什么来阻止我的表单在单击按钮后消失？

Answer 1

需要在每次页面加载时（重新）创建动态控件，其中包括 PostBack。

所以将BindData() 放在Page_Load 中

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    BindData()       
End Sub