http://pietschsoft.com/post/2008/03/PasswordTextBox-for-Silverlight-2-Beta-1.aspx
创建一个PasswordTextBox.cs类，代码如下：
/// Copyright 2008 Chris Pietschmann (http://pietschsoft.com)
/// This work is licensed under a Creative Commons Attribution 3.0 United States License
/// http://creativecommons.org/licenses/by/3.0/us/
///
/// This is a Password TextBox built for use with Silverlight 2 Beta 1
/// The reason this was built, is because the standard TextBox in
/// Silverlight 2 Beta 1 does not have Password support.
/// Original Link: http://pietschsoft.com/post/2008/03/PasswordTextBox-for-Silverlight-2-Beta-1.aspx
///
using System.Windows.Controls;
namespace SilverlightPasswordTextBox
{
public partial class PasswordTextBox : TextBox
{
public PasswordTextBox()
{
this.TextChanged += new TextChangedEventHandler(PasswordTextBox_TextChanged);
this.KeyDown += new System.Windows.Input.KeyEventHandler(PasswordTextBox_KeyDown);
}
#region Event Handlers
public void PasswordTextBox_TextChanged(object sender, TextChangedEventArgs e)
{
if (base.Text.Length ＞= _Text.Length)
_Text += base.Text.Substring(_Text.Length);
DisplayMaskedCharacters();
}
public void PasswordTextBox_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
int cursorPosition = this.SelectionStart;
int selectionLength = this.SelectionLength;
// Handle Delete and Backspace Keys Appropriately
if (e.Key == System.Windows.Input.Key.Back
|| e.Key == System.Windows.Input.Key.Delete)
{
if (cursorPosition ＜ _Text.Length)
_Text = _Text.Remove(cursorPosition, (selectionLength ＞ 0 ? selectionLength : 1));
}
base.Text = _Text;
this.Select((cursorPosition ＞ _Text.Length ? _Text.Length : cursorPosition), 0);
DisplayMaskedCharacters();
}
#endregion
#region Private Methods
private void DisplayMaskedCharacters()
{
int cursorPosition = this.SelectionStart;
// This changes the Text property of the base TextBox class to display all Asterisks in the control
base.Text = new string(_PasswordChar, _Text.Length);
this.Select((cursorPosition ＞ _Text.Length ? _Text.Length : cursorPosition), 0);
}
#endregion
#region Properties
private string _Text = string.Empty;
/// ＜summary＞
/// The text associated with the control.
/// ＜/summary＞
public new string Text
{
get { return _Text; }
set
{
_Text = value;
DisplayMaskedCharacters();
}
}
private char _PasswordChar = '*';
/// ＜summary＞
/// Indicates the character to display for password input.
/// ＜/summary＞
public char PasswordChar
{
get { return _PasswordChar; }
set { _PasswordChar = value; }
}
#endregion
}
}
使用方法：
＜UserControl x:Class="SilverlightApplication1.Page"
xmlns="http://schemas.microsoft.com/client/2007"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:myctl="clr-namespace:SilverlightApplication1; assembly=SilverlightApplication1" Width="600" Height="480"＞
＜Grid x:Name="LayoutRoot" Background="White"＞
＜Canvas Canvas.Top="20"＞
＜myctl:PasswordTextBox x:Name="UserPassword" Width="200" Height="30" Canvas.Top="40" Canvas.Left="20"＞＜/myctl:PasswordTextBox＞
＜/Canvas＞
＜/Grid＞
＜/UserControl＞
注意：要先加入名称空间，具体的值是：
clr-namespace:名称空间全名; assembly=程序集名称
通过使用，发现两个问题：
1，＜myctl:PasswordTextBox PasswordChar="" /＞设置会报错
2，Text="初始值"仍旧是明文