Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

If Not Page.IsPostBack Then
Dim lab As New Label

PlaceHolder1.Controls.Add(lab)
lab.ID = "lab1"
lab.Text = "标签文本"

End If

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim mylab As Label

mylab = PlaceHolder1.FindControl("lab1")
Dim mystr As String
mystr = mylab.Text
Response.Write(mystr)
End Sub



为什么它就运行错误呢。可以把控件添加到页面。但是为什么在点击按钮取控件值的时候就运行错误了呢,

试看看：

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim mylab As Label
mylab=new label

mylab = PlaceHolder1.FindControl(lab1)
Dim mystr As String
mystr = mylab.Text
Response.Write(mystr)
End Sub

要是遍历控件的话是否能将起值取出呢。怎么遍力呢

我也遇到的这样的问题!一起关注如果解决了请和我联系,我的qq:153129771
我现在只是知道 在回传之后动态生成的控件会消失 因此在用findcontrol()
这样的函数是会报错的 !

動態生成的是不是用JS的？你刷新後會重新讀取頁面，當然會把動態生成的控件給干掉的。

http://lujian811.blog.163.com