oreeee
2012-2-11 10:50 AM
Public Class Form1
Private Sub GroupBox1_Enter(sender As System.Object, e As System.EventArgs) Handles GroupBox1.Enter
Dim message As String
If CheckBox1.CheckState = 1 Then
Message = Message & CheckBox1.Text & vbNewLine
End If
End Sub
--------------------------------------------------------------------------------------
令我不解的是上面有标红色颜色的Message有浅青色的线，给的提示是Variable 'message' is used before it has been assigned a value. A null reference exception could result at runtime.
这是怎么回事呢？
我在这里自学的：
http://www.homeandlearn.co.uk/NET/nets4p14.html
Private Sub GroupBox1_Enter(sender As System.Object, e As System.EventArgs) Handles GroupBox1.Enter
Dim message As String
If CheckBox1.CheckState = 1 Then
Message = Message & CheckBox1.Text & vbNewLine
End If
End Sub
--------------------------------------------------------------------------------------
令我不解的是上面有标红色颜色的Message有浅青色的线，给的提示是Variable 'message' is used before it has been assigned a value. A null reference exception could result at runtime.
这是怎么回事呢？
我在这里自学的：
http://www.homeandlearn.co.uk/NET/nets4p14.html
