[C#][Reprint] Several common methods that can only enter numbers in Winform TextBox (C#)

Method 1: 
 
private void tBox_KeyPress(object sender, KeyPressEventArgs e) 
 
 { 
            if (e.KeyChar == 0x20) e.KeyChar = (char)0; //Disable the space key 
            if ((e.KeyChar == 0x2D) && (( (TextBox)sender).Text.Length == 0)) return; //Handle negative numbers 
            if (e.KeyChar> 0x20) 
            { 
                try 
                { 
                    double.Parse(((TextBox)sender).Text + e.KeyChar.ToString( )); 
                } 
                catch 
                { 
                    e.KeyChar = (char)0; //Handling illegal characters 
                } 
            } 
} 
 
Method two: 
 
private void TextBox_KeyPress(object sender, KeyPressEventArgs e) 
 { 
    if(e.KeyChar!=8&&!Char.IsDigit(e.KeyChar)) 
    { 
      e.Handled = true; 
    } 
} 
or 
 
private void TextBox_KeyPress(object sender, KeyPressEventArgs e) 
{ 
    if(e.KeyChar!='\b'&&!Char.IsDigit(e.KeyChar)) 
    { 
      e.Handled = true; 
    } 
 
} 
 
Method 3: 
 
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) 
{ 
if(e.KeyChar!='\b')//This is to allow the backspace key to be entered 
{ 
if((e.KeyChar<'0')||(e.KeyChar>'9'))//This is Allows to enter 0-9 numbers 
{ 
e.Handled = true;  
} 
} 
} 
 
方法四: 
 
private void textBox1_Validating(object sender, CancelEventArgs e)  
{  
const string pattern = @"^\d+\.?\d+{1}quot;;  
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);  
} 
 
方法五: 
 
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; 
} 
 
} 
 
方法六： 
 
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; 
                } 
            }       
  }   
 
Method 7: 
 
Use ASCII code processing method, 
{ 
 
            if ((e.KeyChar <= 48 || e. KeyChar >=57) && (e.KeyChar != 8) && (e.KeyChar != 46)) 
              e.Handled = true; 
===============48 represents 0, 57 represents 9, 8 represents a space, 46 represents a decimal point