vb编程问题

Private Sub Command1_Click()
If Text1.Text = "" And Text2.Text = "" Then
Text3.Text = "0"
endif
If Text1.Text <> "" And Text2.Text <> "" Then
Text3.Text = "3"
endif
If Text1.Text = "1" And Text2.Text = "" Then
Text3.Text = "1"
endif
If Text1.Text = "" And Text2.Text = "2" Then
Text3.Text = "2"
endif
End Sub

Private Sub Form_Load()
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
End Sub

这种题目。。。太没技术含量。建议你多看看书好了。

也就空值的判断，加上txt1的change事件。

这个程序从思路和实现上来说都是很简单的。就是分几种不同的情况进行判断而已。IF TEXT空 THEN TEXT＝。。。类似这样的语句。相信你只要看些基本的书籍就是编写了。

Private Sub Command1_Click()

If (Text1.Text = "" And Text2.Text = "") Then Text3.Text = "0"
If (Text1.Text <> "" And Text2.Text <> "") Then Text3.Text = "3"

If Text1.Text = "1" Then Text3.Text = "1"
If Text2.Text = "2" Then Text3.Text = "2"

End Sub

Private Sub Form_Load()
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""

End Sub

首先清空你工程所有代码，将以上代码直接复制后，直接运行就可以。
当然你要先建立三个文本框，一个Command1按钮才行.在文本框输入完后要点Command1才能得到效果。