限制textbox只能输入数字？

如何限制textbox只能输入数字？

如何限制textbox只能输入数字？

解决方案 »

捕获键盘事件，判断键盘上按下的是什么键，如果不是数字键就return
http://topic.csdn.net/u/20090420/14/50ee45c5-95d6-40e9-bd4b-71cbd80f6b53.html
参考C# WinForm开发系列 - TextBox

<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ErrorMessage="RegularExpressionValidator" ControlToValidate="TextBox1" ValidationExpression='"^[0-9]*$"'></asp:RegularExpressionValidator>

这样....

private void textbox1_KeyPress(object sender, KeyPressEventArgs e)

{

if (!char.IsNumber(e.KeyChar) && ((e.KeyChar != '.') && (e.KeyChar != '\b')))

{

e.Handled = true;

}

}

写好 验证数字的正则表达式然后

1 建立微软的验证控件，在控件中填入上面的正则表达式2 或者写到前台的js脚本中，调用自己写的javascript函数来进行验证

1.正则表达式做验证: Regex reg = new Regex(@"^[1-9]\d*$"); ///不匹配 if (!reg.IsMatch(this.Txt_Int.Text, 0))

2.在textBox中写onkeypress="return event.keyCode>=48&&event.keyCode<=57||event.keyCode==46"

使用验证控件或检查键盘输入的ASCLL码

using System;

using System.ComponentModel;

using System.Windows.Forms;

using System.Windows.Forms.Design;

using System.Runtime.InteropServices;

class NumberTextBox:TextBox

{

[DllImport("user32.dll")]

static extern int SetWindowLong(IntPtr hWnd,int nIndex, int dwNewLong);

[DllImport("user32.dll")]

static extern int GetWindowLong(IntPtr hWnd,int nIndex);

const int GWL_STYLE = (-16);

const int ES_NUMBER = 0x2000;

protected override void OnCreateControl ()

{

base.OnCreateControl ();

//将ES_NUMBER添加到窗体样式

int style= GetWindowLong (Handle,GWL_STYLE);

SetWindowLong (Handle,GWL_STYLE,style|ES_NUMBER);

}

}

class test:Form

{

public test()

{

Text = "Number Only TextBox";

NumberTextBox nt = new NumberTextBox();

Controls.Add (nt);

}

static void Main ()

{

Application.EnableVisualStyles();

Application.Run (new test());

}

}本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/ChrisAK/archive/2008/12/27/3623467.aspx

windows 下通用,还带提示.

上面那个用到了API复杂了点.

改了下更简单:)using System;

using System.ComponentModel;

using System.Windows.Forms;

using System.Windows.Forms.Design;

using System.Runtime.InteropServices;

class NumberTextBox:TextBox

{

const int ES_NUMBER = 0x2000;

protected override CreateParams CreateParams

{

get{

CreateParams ret = base.CreateParams;

ret.Style |= ES_NUMBER;

return ret;

}

}

}

class test:Form

{

public test()

{

Text = "Number Only TextBox";

NumberTextBox nt = new NumberTextBox();

Controls.Add (nt);

}

static void Main ()

{

Application.EnableVisualStyles();

Application.Run (new test());

}

}

效果相同

在TextBox的改变事件里写入正则校验或者ASCII比对都可以....

//判断字符是否为数字

public static bool StrIsInt(string Str)

{

try

{

Int32.Parse(this.textbox1.Text);

return true;

}

catch

{

this.label1.Text="请输入数字";

return false;

}

} 回答者： zengwei61 - 经理 四级 2008-10-13 08:47

Option Strict Off

Option Explicit On

Friend Class Form1

Inherits System.Windows.Forms.Form

Private Sub Text1_KeyPress(ByVal eventSender As System.Object, ByVal eventArgs As System.Windows.Forms.KeyPressEventArgs) Handles Text1.KeyPress

Dim KeyAscii As Short = Asc(eventArgs.KeyChar)

If Not IsNumeric(Chr(KeyAscii)) And KeyAscii <> 8 Then

KeyAscii = 0

End If

eventArgs.KeyChar = Chr(KeyAscii)

If KeyAscii = 0 Then

eventArgs.Handled = True

End If

End Sub

End Class

这个可行，已测试，CTRL+C也不能粘贴其它

只能输入数字：“^[0-9]*$”

只能输入n位的数字：“^d{n}$”

只能输入至少n位数字：“^d{n,}$”

只能输入m-n位的数字：“^d{m,n}$”

只能输入零和非零开头的数字：“^(0|[1-9][0-9]*)$”

只能输入有两位小数的正实数：“^[0-9]+(.[0-9]{2})?$”

只能输入有1-3位小数的正实数：“^[0-9]+(.[0-9]{1,3})?$”

只能输入非零的正整数：“^+?[1-9][0-9]*$”

只能输入非零的负整数：“^-[1-9][0-9]*$”

Private Sub txtUserID_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtUserID.KeyPress

'*************************************

'禁止输入非数字

Dim Str As String = txtUserID.Text

If e.KeyChar = Chr(13) Then

e.Handled = True

ElseIf (e.KeyChar < "0" Or e.KeyChar > "9") And e.KeyChar <> Chr(8) Then

e.Handled = True

End If

End Sub

Private Sub txtUserID_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtUserID.TextChanged

'************************************

'输入数字最大值不超过255

Dim Temp As String

If Val(txtUserID.Text) > 255 Then

txtUserID.Text = ""

Else

Temp = txtUserID.Text

End If

End Sub