在textchanged事件上自定義ASP.NET TextBox

Question

我想讓TextBox控件僅在TextBox中有多個字符時觸發TextChanged事件。

謝謝。

Answer 1

Public Class ZTextBox 
Inherits System.Windows.Forms.TextBox 
Public Event ZTextChanged(ByVal sender As Object, ByVal e As System.EventArgs) 

Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs) 
    MyBase.OnPaint(e) 

    'Add your custom paint code here 
End Sub 

Private Sub ZTextBox_TextChanged1(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.TextChanged 
    If Me.Text.Length > 3 Then 
     RaiseEvent ZTextChanged(sender, e) 
    End If 
End Sub End Class 

，你可以用你的表格下面

Private Sub ZTextBox1_ZTextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ZTextBox1.ZTextChanged 
    MsgBox(1) 
End Sub 

Answer 2

我想你會需要一個自定義控件，它繼承了自定義事件的文本框控件，在內部事件中執行檢查，並在看到合適的時候觸發自定義事件。