vb中关于textbox和buton问题 - 编程论坛

#2

fenglingdihu2010-04-15 17:03

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If TextBox1.Text.Length = 0 Then  '这里是关键
            button1.Visible = False
        Else ： button1.Visible = True
        End If

    End Sub

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        If TextBox1.Text.Length = 0 Then
            button1.Visible = False
        Else ： button1.Visible = True
        End If

    End Sub
End Class 哈哈，终于作出来了

#3

ouxianzhi5202010-04-15 22:52

回复 2楼 fenglingdihu

你这是判断是否有内容，不一定是数值啊。
还应该加一句判断是不是数字

#4

trovar2010-04-16 17:21

回复 2楼 fenglingdihu

多谢！~

#5

yjjpp2302010-05-13 10:04

顶顶！！

#6

faruier2010-05-13 16:11

顶顶顶1

#7

sherry_tm2010-05-14 12:51

你的判断文本框中是否是数字可以用js实现
<script language=javascript>
function onlyNum()
{
if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105)))
//考虑小键盘上的数字键
event.returnvalue=false;
}
</script>
要求文本框中只输数字

#8

sywzs2010-05-14 14:30

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        Button1.Visible = IIf(IsNumeric(TextBox1.Text), True, False)
    End Sub

#9

ouxianzhi5202010-05-16 22:02

以下是引用sywzs在2010-5-14 14:30:51的发言：

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        Button1.Visible = IIf(IsNumeric(TextBox1.Text), True, False)
    End Sub

顶上！