TextBox中只能输入数字的几种常用方法(C#)

TextBox中只能输入数字的几种常用方法(C#)

private void tBox_KeyPress(object sender, KeyPressEventArgs e)

        {

            if (e.KeyChar == 0x20) e.KeyChar = (char)0;  //禁止空格键

            if ((e.KeyChar == 0x2D) && (((TextBox)sender).Text.Length == 0)) return;   //处理负数

            if (e.KeyChar > 0x20)

            {

                try

                {

                    double.Parse(((TextBox)sender).Text + e.KeyChar.ToString());

                }

                catch

                {

                    e.KeyChar = (char)0;   //处理非法字符

                }

            }

        }

private void TextBox_KeyPress(object sender, KeyPressEventArgs e)

   {

    if(e.KeyChar!=8&&!Char.IsDigit(e.KeyChar))

    {

      e.Handled = true;

    }

   }

或者private void TextBox_KeyPress(object sender, KeyPressEventArgs e)

   {

    if(e.KeyChar!='\b'&&!Char.IsDigit(e.KeyChar))

    {

      e.Handled = true;

    }

}

private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)

{

if(e.KeyChar!='\b')//这是允许输入退格键

{

if((e.KeyChar<'0')||(e.KeyChar>'9'))//这是允许输入0-9数字

{

e.Handled = true;

}

}

} 

private void button1_Click(object sender, EventArgs e) 

{ 

string text = this.textBox1.Text; 

if (text != null) 

MessageBox.Show(text); 

} 

private void textBox1_Validating(object sender, CancelEventArgs e) 

{ 

const string pattern = @"^\d+\.?\d+$"; 

string content = ((TextBox)sender).Text; 

if (!(Regex.IsMatch(content, pattern))) 

{ 

errorProvider1.SetError((Control)sender, "只能输入数字!"); 

e.Cancel = true; 

} 

else 

errorProvider1.SetError((Control)sender, null); 

}

private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)

{

if(e.KeyChar=='.' && this.textBox1.Text.IndexOf(".")!=-1)

{

e.Handled=true;

}

if(!((e.KeyChar>=48 && e.KeyChar<=57) || e.KeyChar=='.' || e.KeyChar==8))

{

e.Handled=true;

}

}

  private void tbx_LsRegCapital_KeyPress(object sender, KeyPressEventArgs e)

        {

            if (!Char.IsNumber(e.KeyChar) && !Char.IsPunctuation(e.KeyChar) && !Char.IsControl(e.KeyChar))

            {

                e.Handled = true;//消除不合适字符

            }

            else if (Char.IsPunctuation(e.KeyChar))

            {

                if (e.KeyChar != '.' || this.textBox1.Text.Length == 0)//小数点

                {

                    e.Handled = true;

                }

                if (textBox1.Text.LastIndexOf('.') != -1)

                {

                    e.Handled = true;

                }

            }      

        }

利用ASCII码处理办法、

{

            if ((e.KeyChar <= 48 || e.KeyChar >=57) && (e.KeyChar != 8) && (e.KeyChar != 46))

              e.Handled = true;

================48代表0，57代表9，8代表空格，46代表小数点

}

来自：http://bbs.bccn.net/thread-205138-1-1.html