VB文本框限制输入类型

VB文本框可以利用Ascii字符来限定输入的内容类型，这里我分了两大部分来阐述怎样限制数据类型，其实原理都是一样的，都是Ascii字符范围设定的问题，大家可以根据Ascii表来限制数据类型。

一、私有过程，不可调用

1、限定只输入汉字

代码：

Private Sub txtDirector_KeyPress(KeyAscii As Integer)If KeyAscii >= -20319 And KeyAscii <= -3652 Or KeyAscii = 8 Then          Else          KeyAscii = 0          MsgBox "请输入汉字！", vbOKOnly + vbExclamation, "警告"          txtDirector.SetFocus          End IfEnd Sub

这条语句用来判断输入的字符是否是汉字，如果不是汉字，就把这个输入的字符屏蔽掉。
keyAscii=0的字符是“空格”，keyAscii=8的字符是“退格”
 

2、限定只输入数字 

 查ASCII码表，得到0的ASCII码是48。输入以下语句：

 If KeyAscii < 48 Or KeyAscii > 57 Then KeyAscii = 0

这条语句用来判断输入的字符是否在0-9的范围，如果不在这个范围，就把这个输入的字符屏蔽掉。（。其他的地方和上面的代码原理都是一样的 。

 
如果输入的数字可能是小数，那么还要添加如下代码：
 If KeyAscii = 46 And Not CBool(InStr(txbNumber, ".")) Then Exit Sub

当输入小数点时，程序判断文本框中是否已有小数点（因为一个小数中不可能有多个小数点），如果没有小数点，则允许输入。

二、公有过程，在模块中可调用

代码：

Option ExplicitPublic Enum FormatType    [数字_正整数] = 0    [数字_正负整数] = 1    [数字_正小数] = 2    [数字_正负小数] = 3    [字母_任意书写] = 4    [字母_锁定小写] = 5    [字母_锁定大写] = 6    [汉字_锁定中文] = 7End EnumFunction TextFormat(txtObj As TextBox, KeyAscii As Integer, Optional FormatType As FormatType = 0) As IntegerDim ReturnKeyCode As Integer    Select Case FormatType        Case 0            ReturnKeyCode = TextFormat_0(txtObj, KeyAscii)        Case 1            ReturnKeyCode = TextFormat_1(txtObj, KeyAscii)        Case 2            ReturnKeyCode = TextFormat_2(txtObj, KeyAscii)        Case 3            ReturnKeyCode = TextFormat_3(txtObj, KeyAscii)        Case 4            ReturnKeyCode = TextFormat_4(txtObj, KeyAscii)        Case 5            ReturnKeyCode = TextFormat_5(txtObj, KeyAscii)        Case 6            ReturnKeyCode = TextFormat_6(txtObj, KeyAscii)        Case 7            ReturnKeyCode = TextFormat_7(txtObj, KeyAscii)    End Select    TextFormat = ReturnKeyCodeEnd Function'====================================================='数字_正整数'=====================================================Private Function TextFormat_0(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_0 = KeyAscii: Exit Function    If KeyAscii = Asc("0") And Len(txtObj.Text) = 0 Then TextFormat_0 = 0: Exit Function    If KeyAscii < Asc("0") Or KeyAscii > Asc("9") Then        TextFormat_0 = 0        Exit Function    End If    TextFormat_0 = KeyAsciiEnd Function'====================================================='数字_正负整数'=====================================================Private Function TextFormat_1(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_1 = KeyAscii: Exit Function    If KeyAscii = Asc("0") And Len(txtObj.Text) = 0 Then TextFormat_1 = 0: Exit Function    If KeyAscii = Asc("-") And Len(txtObj.Text) > 0 Then TextFormat_1 = 0: Exit Function    If KeyAscii = Asc("-") And Len(txtObj.Text) = 0 Then TextFormat_1 = KeyAscii: Exit Function    If KeyAscii < Asc("0") Or KeyAscii > Asc("9") Then        TextFormat_1 = 0        Exit Function    End If    TextFormat_1 = KeyAsciiEnd Function'====================================================='数字_正小数'=====================================================Private Function TextFormat_2(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_2 = KeyAscii: Exit Function    If KeyAscii = Asc(".") And InStr(1, txtObj.Text, ".") > 0 Then TextFormat_2 = 0: Exit Function    If (KeyAscii = Asc(".") Or KeyAscii = Asc("0")) And Len(txtObj.Text) = 0 Then txtObj.Text = "0.": txtObj.SelStart = Len(txtObj.Text): TextFormat_2 = 0: Exit Function    If KeyAscii = Asc(".") Then TextFormat_2 = KeyAscii: Exit Function    If KeyAscii < Asc("0") Or KeyAscii > Asc("9") Then        TextFormat_2 = 0        Exit Function    End If    TextFormat_2 = KeyAsciiEnd Function'====================================================='数字_正负小数'=====================================================Private Function TextFormat_3(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_3 = KeyAscii: Exit Function    If KeyAscii = Asc("-") And Len(txtObj.Text) > 0 Then TextFormat_3 = 0: Exit Function    If KeyAscii = Asc("-") And InStr(1, txtObj.Text, "-") = 0 Then TextFormat_3 = KeyAscii: Exit Function    If KeyAscii = Asc(".") And InStr(1, txtObj.Text, ".") > 0 Then TextFormat_3 = 0: Exit Function    If (KeyAscii = Asc(".") Or KeyAscii = Asc("0")) And Len(txtObj.Text) < 2 Then txtObj.Text = txtObj.Text & "0.": txtObj.SelStart = Len(txtObj.Text): TextFormat_3 = 0: Exit Function    If KeyAscii = Asc(".") Then TextFormat_3 = KeyAscii: Exit Function    If KeyAscii < Asc("0") Or KeyAscii > Asc("9") Then        TextFormat_3 = 0        Exit Function    End If    TextFormat_3 = KeyAsciiEnd Function'====================================================='字母_任意书写'=====================================================Private Function TextFormat_4(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_4 = KeyAscii: Exit Function    If Not ((KeyAscii >= Asc("a") And KeyAscii <= Asc("z")) Or (KeyAscii >= Asc("A") And KeyAscii <= Asc("Z"))) Then        TextFormat_4 = 0        Exit Function    End If    TextFormat_4 = KeyAsciiEnd Function'====================================================='字母_锁定小写'=====================================================Private Function TextFormat_5(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_5 = KeyAscii: Exit Function    If Not ((KeyAscii >= Asc("a") And KeyAscii <= Asc("z")) Or (KeyAscii >= Asc("A") And KeyAscii <= Asc("Z"))) Then        TextFormat_5 = 0        Exit Function    End If    If KeyAscii >= Asc("A") And KeyAscii <= Asc("Z") Then KeyAscii = KeyAscii + 32    TextFormat_5 = KeyAsciiEnd Function'====================================================='字母_锁定大写'=====================================================Private Function TextFormat_6(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_6 = KeyAscii: Exit Function    If Not ((KeyAscii >= Asc("a") And KeyAscii <= Asc("z")) Or (KeyAscii >= Asc("A") And KeyAscii <= Asc("Z"))) Then        TextFormat_6 = 0        Exit Function    End If    If KeyAscii >= Asc("a") And KeyAscii <= Asc("z") Then KeyAscii = KeyAscii - 32    TextFormat_6 = KeyAsciiEnd Function'====================================================='汉字_锁定中文'=====================================================Private Function TextFormat_7(txtObj As TextBox, KeyAscii As Integer) As Integer    If KeyAscii = 8 Then TextFormat_7 = KeyAscii: Exit Function    If KeyAscii >= 0 And KeyAscii <= 255 Then        TextFormat_7 = 0        Exit Function    End If    TextFormat_7 = KeyAsciiEnd Function