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[ASP.net教程]WPF学习之路(五) 实例:写字板(续)


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="1">      <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="2" 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...