如何在silverlight中製作xaml文本框只接受最大小數點精度的數字

Question

如何在silverlight中製作xaml文本框只接受最大一個小數點精度的數字。我試過這個問題的答案How to make a textBox accept only Numbers and just one decimal point in Windows 8。但它沒有奏效。我怎樣才能做到這一點 ？

Answer 1

你可以寫這樣的功能，

txtDiscount.KeyDown += new KeyEventHandler(EnsureNumbers); 

//方法只允許數字，

void EnsureNumbers(object sender, KeyEventArgs e) 
    { 
     if (e.Key == Key.Tab) 
     { 
      return; 
     } 
     bool result = EnsureDecimalPlaces(); 
     if (result == false) 
     { 
      var thisKeyStr = ""; 
      if (e.PlatformKeyCode == 190 || e.PlatformKeyCode == 110) 
      { 
       thisKeyStr = "."; 
      } 
      else 
      { 
       thisKeyStr = e.Key.ToString().Replace("D", "").Replace("NumPad", ""); 
      } 
      var s = (sender as TextBox).Text + thisKeyStr; 
      var rStr = "^[0-9]+[.]?[0-9]*$"; 
      var r = new Regex(rStr, RegexOptions.IgnoreCase); 
      e.Handled = !r.IsMatch(s); 
     } 
     else 
     { 
      e.Handled = true; 
     } 
    } 

方法，以確保只有1位小數，

bool EnsureDecimalPlaces() 
    { 

     string inText = txtDiscount.Text; 
     int decPointIndex = inText.IndexOf('.'); 
     if (decPointIndex < 1 || decPointIndex == 1) 
     { 
      return false; 
     } 
     else 
      return true; 
    }