事件处理程序执行两次 [英] Event Handler executes twice
本文介绍了事件处理程序执行两次的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在使用visual studio 2008编写一个Web应用程序。
如果在运行应用程序时单击了发送按钮,它的事件处理程序执行两次,原因我不知道和从而返回结果两次。
任何人都可以帮助我吗?以下是事件处理程序以防万一:
受保护 Sub btnSend_Click( ByVal 发件人作为 对象, ByVal e As System.EventArgs) Handles btnSend.Click
'用于保存结果的维数组
Dim UserArray 作为用户()= 新用户(){}
btnSend.Enabled = False
'Label1.Text =""
'如果没有输入departmentId,请将d值设置为零以避开错误。否则解析输入的值。
Dim deptId As 整数
如果 txtDeptID.Text<> "" 然后
deptId = 整数 .Parse(txtDeptID.Text)
Else
deptId = 0
结束 如果
尝试
UserArray = myRequests.GetUsers(txtUserID.Text,txtFName.Text,txtLName.Text,txtOName.Text,deptId)
Catch ex As 异常
MsgBox(ex.Message)
结束 尝试
'检查是否有注册用户。
如果 UserArray Nothing < span style ="color:Blue;">然后
'标签1.Text ="没有要显示的结果"
btnSend.Enabled = True
退出 Sub
End 如果
'clear gridview添加新项目
'tableUsers.Rows.Clear()
'检索当前用户的属性并添加到表
对于 每个 eachUser 在 UserArray
'为当前正在检索的用户声明一个新的tableRow
Dim ro As New TableRow
对于 i 作为 整数 = 0 To 3
Dim celCol As TableCell = New TableCell
选择 案例 i
Case 0
celCol.Text = eachUser.userID
Case 1
celCol.Text = eachUser.firstName
Case 2
celCol.Text = eachUser.lastName
案例 3
celCol.Text = eachUser.otherName
End 选择
'将当前单元格添加到行集合中。
ro.Cells.Add(celCol)
Next
''最后,将行添加到表
tableUsers.Rows。添加(ro)
下一步
btnSend.Enabled = True
结束 Sub
解决方案
尝试搜索"btnSend.Click + =";也许您以编程方式在设计器文件或其他地方以及标记代码中注册事件。
protected void Page_Load(object sender,EventArgs e)
{
this.btnSend.Click + = this.btnSend_Click;
}
protected void btnSend_Click(object sender,EventArgs e)
{
// ...
}
i am writing a web application using visual studio 2008.
if the send button is clicked while running the application, it's event handlers executes twice for reasons i dont know and thereby returns the result two times.
can anyone help me? the event handler is below in case it may help:
Protected Sub btnSend_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSend.Click 'dimension array to hold results Dim UserArray As User() = New User() {} btnSend.Enabled = False 'Label1.Text = "" 'if no departmentId is entered, set d value to zero to evade error. else parse the value entered. Dim deptId As Integer If txtDeptID.Text <> "" Then deptId = Integer.Parse(txtDeptID.Text) Else deptId = 0 End If Try UserArray = myRequests.GetUsers(txtUserID.Text, txtFName.Text, txtLName.Text, txtOName.Text, deptId) Catch ex As Exception MsgBox(ex.Message) End Try 'check if there are any registered users. If UserArray Is Nothing Then 'Label1.Text = "There are no results to show" btnSend.Enabled = True Exit Sub End If 'clear gridview to add new items 'tableUsers.Rows.Clear() 'retrieve the properties of the current user and add to table For Each eachUser In UserArray 'declare a new tableRow for current user being retrieved Dim ro As New TableRow For i As Integer = 0 To 3 Dim celCol As TableCell = New TableCell Select Case i Case 0 celCol.Text = eachUser.userID Case 1 celCol.Text = eachUser.firstName Case 2 celCol.Text = eachUser.lastName Case 3 celCol.Text = eachUser.otherName End Select 'add current cell to the row collection. ro.Cells.Add(celCol) Next 'finally, add the row to the table tableUsers.Rows.Add(ro) Next btnSend.Enabled = True End Sub解决方案Try to search for "btnSend.Click +=" maybe you register the event programmatically in the designer file or somewhere else and in Markup code itself.
protected void Page_Load(object sender, EventArgs e) { this.btnSend.Click += this.btnSend_Click; } protected void btnSend_Click(object sender, EventArgs e) { // ... }
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