WordPad 2.0
上一期实现了一虽然建议但是功能比较全面的Wordpad程序，但是程序代码略显繁琐，这一期更新改进版。
MainWindows.xaml
添加 <Window.CommandBindings>节点，响应保存和关闭命令
<Window.CommandBindings>
<CommandBinding Command="Close" Executed="CloseCommand" />
<CommandBinding Command="Save" Executed="SaveCommand" CanExecute="SaveCanExecute" />
</Window.CommandBindings>
Menu
<MenuItem Header="File">
<MenuItem Header="Copy" Command="Copy" />
<MenuItem Header="Paste" Command="Paste" />
<MenuItem Header="Cut" Command="Cut" />
<Separator></Separator>
<MenuItem Header="Save" Command="Save" />
<MenuItem Header="Close" Command="Close" />
</MenuItem>
Tool
<ToolBar Grid.Row="">
<Button Command="Copy">
<Image Source="/Images/Copy16x16.png" />
</Button>
<Button Command="Paste">
<Image Source="/Images/Paste16x16.png" />
</Button>
<Button Command="Cut">
<Image Source="/Images/Cut16x16.png" />
</Button>
<Button Command="Save">
<Image Source="/Images/Save16x16.png" />
</Button>
<Button Command="Close">
<Image Source="/Images/Close16x16.png" />
</Button>
</ToolBar>
TextBox
<TextBox Grid.Row="" AcceptsReturn="True" TextChanged="TextBox_TextChanged" />
MainWindow.xmal.cs
public partial class MainWindow : Window
{
private bool isDirty = false; public MainWindow()
{
InitializeComponent();
} private void CloseCommand(object sender, ExecutedRoutedEventArgs e)
{
MessageBox.Show("CloseCommand triggered with " + e.Source);
App.Current.Shutdown();
} private void SaveCommand(object sender, ExecutedRoutedEventArgs e)
{
MessageBox.Show("SaveCommand triggered with " + e.Source);
isDirty = false;
} private void SaveCanExecute(object sender, CanExecuteRoutedEventArgs e)
{
e.CanExecute = isDirty;
} private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
isDirty = true;
}
}
邮件菜单，快捷键，状态控制等功能已经全部实现
解析
所有功能都是通过Command来驱动的
用到的Command
ApplicationCommands.Save
ApplicationCommands.Paste
ApplicationCommands.Cut
ApplicationCommands.Save
ApplicationCommands.Close
TextBox直接支持前三种命令（WordPad1.0中原版使用的是TextBlock，不支持这三种命令，小编手滑，勿用了TextBox）
保存和关闭命令需要有响应的命令处理函数，首先设置Menu和ToolBar的Command属性，通过Command Binding关联Command和处理函数
执行Command时，会触发Execute事件。触发CanExecute事件时，事件处理函数需要返回CanExecute属性，告知系统是否可用
To be continue...