VB中能不能将文本框的输入数值限定为一个范围

比如，你要对Text1的输入进行限制。可以使用下面代码：

Private Sub Text1_Change()
If Val(Trim(Text1.Text)) < 0 Or Val(Trim(Text1.Text)) > 255 Then
Text1.Text = ""
End If
End Sub
Private Sub Text1_KeyPress(KeyAscii As Integer)
 '禁止输入非数字字符
    If KeyAscii < 48 Or KeyAscii > 57 Then
    KeyAscii = 0
    End If
End Sub

Private Sub Text1_Change() Text1 = Int(Val(Text1)) If Text1 > 255 Then Text1 = 255 End Sub

不知道这个行不行,你先试一试

dim rgbvalue as integer

dim rgbvalueback as integer

dim r as integer

dim g as integer

dim b as integer

r = hscrollbar1.value

g = hscrollbar2.value

b = hscrollbar3.value

textbox1.text = r

textbox2.text = g

textbox3.text = b

rgbvalue = rgb(r, g, b)

rgbvalueback = rgb(255 - r, 255 - g, 255 - b)

me.backcolor = system.drawing.colortranslator.fromole(rgbvalue)

label1.backcolor = system.drawing.colortranslator.fromole(rgbvalue)

label2.backcolor = system.drawing.colortranslator.fromole(rgbvalue)

label3.backcolor = system.drawing.colortranslator.fromole(rgbvalue)

label1.forecolor = system.drawing.colortranslator.fromole(rgbvalueback)

label2.forecolor = system.drawing.colortranslator.fromole(rgbvalueback)

label3.forecolor = system.drawing.colortranslator.fromole(rgbvalueback)