为什么我的活动会运行两次？

Question

我有一个按钮

 <asp:Button ID="Button1" runat="server" Text="Button"  onclick="Button1_Click" UseSubmitBehavior="False" />

我的活动是

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim con As New SqlConnection(ConfigurationManager.ConnectionStrings("Document_RecordConnectionString1").ToString())
        con.Open()
        Dim del As New SqlCommand(" delete from TableA where RefNo = '" & Request.QueryString("RefNo") & "'", con)
        del.ExecuteNonQuery()
        For i As Integer = 0 To displayCBL.Items.Count - 1

            If displayCBL.Items(i).Selected Then
                Dim cmd As New SqlCommand("Insert into TableA (RefNo,Text,InsertDate) values('" & Request.QueryString("RefNo") & "','" & displayCBL.Items(i).Value & "',getdate())", con)
                cmd.ExecuteNonQuery()

            End If
        Next
        con.Close()
End Sub

我注意到我的子例程运行了两次，因此插入了两次数据（调试器和 SQL Server 分析器都确认了这一点）。有什么我想念的吗？

Answer 1

答案很简单。上面的代码两次调用事件。同时拥有onclick="Button1_Click" 或Handles Button1.Click 是错误的。任选其一即可。

您可以阅读更多内容：

OnClick and Handles Caution: Events Firing Twice

ASP.Net OnClick vs Function() Handles buttonName.Click