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GridView中记录的删除。我知道使用ItemTemplate中的asp:LinkButton可以更容易地做到这一点，但是我正在尝试将它附加到CommandField - ShowDeleteButton按钮。

我试着遵循本教程：display-confirmation-message-on-gridview-deleting

我是GridView新手，我的实现是用VB.Net而不是C#实现的。下面是我尝试注入Javascript函数的代码，我不知道为什么我的row.cell引用是错误的：

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

下面是我的GridView标记片段(比所有绑定的列都要多一点；我在第一个也是唯一的TemplateField到达第5列之后计数了3个TemplateField项，因此i=4)：

<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，命令按钮确实在第5列中：

​

​

在没有尝试/捕获的情况下，我得到的错误是：

​

Answer 1

如果您还没有搞清楚，那么您的问题就出现在ButtonType="Button"中：

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

不能用命令按钮来链接按钮。您必须将其定义为链接按钮(有关MSDN类的详细信息，请参阅CommandField )。这是行之有效的：

<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函数并请求确认。如果它返回true，则可以调用服务器端代码来删除。

下面是解释的代码

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

下面是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;
}

​

您可以在下面的链接中使用源代码查看详细文章。

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

谢谢

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