Command

ICommand:

bool CanExcecute: 表示命令是否可以执行

Execute(object）：执行命令，并输入object参数

CanExecuteChanged:

ICommandSource:

Command, CommandParameter, CommandTarget

CommandBinding

定义和关联Command的具体实现

<Window.CommandBindings>
	<CommandBinding Command="Application.Open" 
      Executed="OpenCmdExecuted"
      CanExecute="OpenCmdCanExecute" />
</Window.CommandBindings>

Routed Command

当调用CanExeucte方法时，分别会产生CanExecute和PreviewCanExecute

当调用Execute方法时，会产生Executed和PreviewExecuted

Command Repository

WPF中内置的命令包括：

ApplicationCommands, NavigationCommands, MediaCommands, EditingCommands, ComponentCommands

<Window>
	<Window.CommandBindings>
  	<CommandBinding Command="Help" CanExecute="HelpCanExecute"
          Executed="HelpExecuted" />
  </Window.CommandBindings>
  <Window.InputBindings>
    <KeyBinding Command="Help" Key="H" Modifiers="Ctrl"/>
    <MouseBinding Command="Help" MouseAction="LeftDoubleClick"/>
  </Window.InputBindings>
  <StackPanel>
  	<Button Command="Help" Content="帮助"/>
  </StackPanel>
</Window>

private void HelpCanExecute(object sender, CanExecuteRoutedEventArgs e)
{
	e.CanExecute=true;
    e.Handle=true;
}

InputBindings

可以将鼠标或者键盘的事件和Command关联起来。

<Label Style="{StaticResource FS_Label}" HorizontalContentAlignment="Left" FontSize="14" Content="{Binding ItemName}" Width="{Binding Path=ActualWidth, ElementName=deviceStatusListBox}" Background="Transparent">
   <Label.InputBindings>
       <MouseBinding MouseAction="LeftDoubleClick" Command="{Binding DataContext.MenuItemDoubleClickCommand, UpdateSourceTrigger=PropertyChanged, ElementName=deviceStatusListBox}" CommandParameter="{Binding Path=SelectedItem, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBox}}}"/>
   </Label.InputBindings>
</Label>

Command Parameter:

Parameter的值是支持绑定的，也可以是普通的值

<Button Command="NavigationCommands.Zoom" 
  CommandParameter="{Binding ElementName=txtZoom, Path=Text}">
  Zoom To Value
</Button>

UI event to command:

需要使用到Prism的框架。

<Window ...
  xmlns:i="http://schemas.microsoft.com/xaml/behaviors"
        xmlns:prism="http://prismlibrary.com/">
<ListBox Grid.Row="1" Margin="5" ItemsSource="{Binding Items}" SelectionMode="Single">
   <i:Interaction.Triggers>
       <!-- This event trigger will execute the action when the corresponding event is raised by the ListBox. -->
       <i:EventTrigger EventName="SelectionChanged">
           <!-- This action will invoke the selected command in the view model and pass the parameters of the event to it. -->
           <prism:InvokeCommandAction Command="{Binding SelectedCommand}" TriggerParameterPath="AddedItems" />
       </i:EventTrigger>
   </i:Interaction.Triggers>
</ListBox>
</Window>