Question

在vb.net中,怎样表达TextBox.Text值的变动

怎样表达TextBox.Text值的变动，我知道如果是事件的话应该是TextChenged。

我是想表达成这样，在省略号的地方怎样表达为TextBox.Text值的变动

If TextBox1.Text…… Then
MessageBox(你好！)
End If

也就是在语句中表达如果TextBox1的Text值变动，就弹出“你好”。
在省略号的地方应该填成什么？

Answer 1

Public Class Form1

Public flag As Boolean = False

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
flag = True
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Timer1.Enabled = True
End Sub

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
If flag = True Then
flag = False
MsgBox("你好！")
End If
End Sub

End Class

Answer 2

if textbox1.text<>empty then
MessageBox(你好！)
End If