在Silverlight 2中创建密码输入框

Silverlight Beta2中，没有提供密码输入框控件，估计在正式版里应该提供吧。Chris Pietschmann自己写了一个，原文地址是： 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