如何使用GridView ShowDeleteButton CommandField显示确认消息

Question

我试图附加一个Javascript函数来确认删除GridView中的记录。我知道这可以在ItemTemplate中使用asp：LinkBut​​ton更容易地完成，但我试图将它附加到CommandField - ShowDeleteButton按钮。

我已尝试按照本教程：display-confirmation-message-on-gridview-deleting

我是GridView的新手，我的实现是在VB.Net而不是C＃。这是我尝试注入Javascript函数的代码，我无法弄清楚我的row.cell引用是如何/为什么错误的：

Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs) _
    Handles GridView1.RowDataBound
    If e.Row.RowState <> DataControlRowState.Edit Then
        If e.Row.RowType = DataControlRowType.DataRow Then  'check for RowType DataRow
            Dim id As String = e.Row.Cells(0).Text      'get the position to be deleted
           Try
            'cast the ShowDeleteButton link to linkbutton
            Dim lb As LinkButton
            Dim i As Integer = 4            'cell we want in the row (relative to 0 not 1) 
            lb = DirectCast(e.Row.Cells(i).Controls(2), LinkButton)
            If lb IsNot Nothing Then        'attach the JavaScript function with the ID as the parameter
                lb.Attributes.Add("onclick", "return ConfirmOnDelete('" & id & "');")
            End If
           Catch ex As Exception
           End Try
        End If
    End If

这是我的GridView标记片段（比所有绑定列更繁忙;我在第一个和唯一的BoundField到达第5列之后计算3个TemplateField项，因此i = 4以上）：

<Columns>
    <asp:BoundField DataField="PositionID" HeaderText="ID" ReadOnly="true" />
    <asp:TemplateField HeaderText="PositionTitle">
        <ItemTemplate>
            <%# Eval("PositionTitle")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox runat="server" ID="txtPositionTitle" Text='<%# Eval("PositionTitle")%>' />
        </EditItemTemplate>
    </asp:TemplateField>
    <asp:TemplateField HeaderText="Incumbent">
        <ItemTemplate>
            <asp:Label ID="lblUser" runat="server" Text='<%# Eval("Incumbent")%>'></asp:Label>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:Label ID="lblUser" runat="server" Text='<%# Eval("Incumbent")%>' Visible = "false"></asp:Label>            
            <asp:DropDownList Width="100%" runat="server" 
               id="ddlUsers" AutoPostBack="true" 
               DataTextField="FullName" DataValueField="UserID"
               OnSelectedIndexChanged="ddlUsers_SelectedIndexChanged">
            </asp:DropDownList> 
        </EditItemTemplate> 
    </asp:TemplateField>
    <asp:TemplateField HeaderText="Backup">
        <ItemTemplate>
            <%#Eval("Backup")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:Label ID="lblBackup" runat="server" Text='<%# Eval("Backup")%>' Visible = "false"></asp:Label>         
            <asp:DropDownList Width="100%" runat="server" 
               id="ddlUsersBackup" AutoPostBack="true" 
               DataTextField="FullName" DataValueField="UserID"
               OnSelectedIndexChanged="ddlUsersBackup_SelectedIndexChanged">
            </asp:DropDownList> 
        </EditItemTemplate>     
    </asp:TemplateField>

    <asp:CommandField ButtonType="Button" ControlStyle-CssClass="coolbutton" 
        ShowEditButton="true" 
        ShowDeleteButton="true"
        ShowCancelButton="true" /> 

当我忽略错误时，Command按钮确实位于第5列：

没有Try / Catch我得到的错误是：

Answer 1

如果您还没有想到，那么您的问题出在ButtonType="Button"：

 <asp:CommandField ButtonType="Button" ControlStyle-CssClass="coolbutton" 
        ShowEditButton="true" 
        ShowDeleteButton="true"
        ShowCancelButton="true" /> 

您无法将命令按钮强制转换为链接按钮。您必须将其定义为链接按钮（有关CommandField类的详细信息，请参阅MSDN）。这是有效的：

<asp:CommandField ButtonType="Link" ControlStyle-CssClass="coolbutton" 
            ShowEditButton="true" 
            ShowDeleteButton="true"
            ShowCancelButton="true" /> 

Answer 2

只需在onclientclick事件上调用javascript函数并要求确认。如果返回true，则可以调用服务器端代码进行删除。

以下是解释代码

<asp:LinkButton ID="lbDelete" runat="server" OnClick="lbDelete_Click" OnClientClick="return fnConfirm();"> Delete</asp:LinkButton>

以下是javascript函数：

<script type="text/javascript">
function fnConfirm() {
    if (confirm("The item will be deleted. Are you sure want to continue?") == true)
        return true;
    else
        return false;
}

您可以在以下链接中查看包含源代码的详细文章

http://www.dotnetpickles.com/2013/03/how-to-show-confirm-message-while.html

由于

Answer 3

我找到了很多C＃答案。

aspx页面：

<asp:CommandField DeleteText="Delete" ShowDeleteButton="true" 
     ButtonType="Button" />

aspx.vb页面：

Protected Sub GridView1_RowDataBound(sender As Object, _
                                 e As GridViewRowEventArgs) _
                                 Handles GridView1.RowDataBound
     If e.Row.RowType = DataControlRowType.DataRow Then

        If (e.Row.RowState <> DataControlRowState.Edit) Then
            Dim oButton As Button
            oButton = CType(e.Row.Cells(14).Controls(0), Button)
            oButton.OnClientClick = _
                "if (confirm(""Are you sure you wish to Delete?"") == false) return;"
        End If

    End If
End Sub