ApplicationCommands用于表示应用程序程序员经常遇到的常见命令,类似于ctrl+c
在WPF中,许多控件都自动集成了固有的命令集。比如文本框TextBox就提供了复制(Copy),粘贴(Paste),裁切(Cut),撤消(Undo)和重做(Redo)命令等。
WPF提供常用应用程序所用的命令集,常用的命令集包括:ApplicationCommands, ComponentCommands, NavigationCommands, MediaCommands和EditingCommands。
ApplicationCommands(应用程序命令): CancelPrint:取消打印 Close:关闭 ContextMenu:上下文菜单 Copy:复制 CorrectionList: Gets the value that represents the Correction List command. Cut:剪切 Delete:删除 Find:查找 Help:帮助 New:新建 NotACommand:不是命令,被忽略 Open:打开 Paste:粘贴 Print:打印 PrintPreview:打印预览 Properties:属性 Redo:重做 Replace:取代 Save:保存 SaveAs:另存为 SelectAll:选择所有的 Stop:停止 Undo:撤消
ComponentCommands(组件命令): ExtendSelection:后接Down/Left/Right/Up, 比如:ExtendSelectionDown(Shift+Down,Extend Selection Down),ExtendSelectionLeft等 Move:后接Down/Left/Right/Up, 如:MoveDown MoveFocus:后接Down/Forward/Back/Up, 如:MoveFocusDown MoveFocusPage:后接Down/Up,如:MoveFocusPageUp MoveTo:后接End/Home/PageDown/PageUp,比如:MoveToPageDown ScrollByLine ScrollPage:后接Down/Left/Right/Up,比如:ScrollPageLeft SelectTo:End/Home/PageDown/PageUp,比如:SelectToEnd
NavigationCommands(导航命令): Browse浏览: 后接Back/Forward/Home/Stop, 比如:BrowseBack 缩放显示:DecreaseZoom, IncreaseZoom, Zoom Favorites(收藏) 页面:FirstPage, LastPage, PreviousPage, NextPage,GoToPage NavigateJournal Refresh(刷新) Search(搜索)
MediaCommands(多媒体控制命令): Treble高音:DecreaseTreble,IncreaseTreble Bass低音:BoostBass,DecreaseBass,IncreaseBass Channel频道:ChannelDown,ChannelUp MicrophoneVolume麦克风音量调节:DecreaseMicrophoneVolume,IncreaseMicrophoneVolume,MuteMicrophoneVolume ToggleMicrophoneOnOff:麦克风开关 Volume音量: DecreaseVolume,IncreaseVolume,MuteVolume Rewind, FastForward(回放,快进) Track轨道:PreviousTrack,NextTrack [上一段(节)] Play,Pause,Stop,Record(播放,暂停,停止,录制) TogglePlayPause Select选择
EditingCommands(编辑/排版类命令): Align对齐:AlignCenter,AlignJustify,AlignLeft,AlignRight(居中,撑满,左对齐,右对齐) Backspace退格 TabForward,TabBackward(Tab前缩,Tab向后) FontSize字体大小:DecreaseFontSize,IncreaseFontSize Indentation缩排:DecreaseIndentation, IncreaseIndentation Delete删除: Delete选中部分,DeleteNextWord:删除后一字,DeletePreviousWord:删除前一字 EnterLineBreak:换行 EnterParagraphBreak:换段 CorrectSpellingError/IgnoreSpellingError:纠正/忽略拼写错误 MoveUpByLine,MoveDownByLine: 上/下移一行, MoveUpByPage,MoveDownByPage: 上/下移一页 MoveUpByParagraph,MoveDownByParagraph: 上/下移一段 MoveLeftByCharacter/MoveRightByCharacter:左/右移一字符 MoveLeftByWord/MoveRightByWord 左/右移一词 MoveToDocumentStart/MoveToDocumentEnd:到文章开头/结尾 MoveToLineStart/MoveToLineEnd:到一行的开头/结尾 SelectUpByLine,SelectDownByLine:向上/下选一行 SelectUpByPage,SelectDownByPage:向上/下选一页 SelectUpByParagraph,SelectDownByParagraph:向上/下选一段 SelectLeftByCharacter,SelectRightByCharacter:向左/右选中一字 SelectLeftByWord,SelectRightByWord:向左/右选中一词 SelectToDocumentStart,SelectToDocumentEnd: 选中到篇头/篇尾 SelectToLineStart/SelectToLineEnd:选中到行首/行尾 ToggleBold, ToggleItalic, ToggleUnderline(加粗,斜体,下划线) ToggleBullets, ToggleNumbering(列表:加点,加数字) ToggleInsert:插入 ToggleSuperscript,ToggleSubscript(上标字,下标字)
先来举一个简单的例子:
XAML代码: <StackPanel> <Menu> <MenuItem Command="ApplicationCommands.Paste" /> </Menu> <TextBox /> </StackPanel>
C#代码: StackPanel mainStackPanel = new StackPanel(); TextBox pasteTextBox = new TextBox(); Menu stackPanelMenu = new Menu(); MenuItem pasteMenuItem = new MenuItem();
stackPanelMenu.Items.Add(pasteMenuItem); mainStackPanel.Children.Add(stackPanelMenu); mainStackPanel.Children.Add(pasteTextBox);
pasteMenuItem.Command = ApplicationCommands.Paste;
上面代码演示了将对文本框设置为焦点时,菜单项可用,点击菜单项时,将执行粘贴命令。
下面列出关于Command的四个概念和四个小问题: 1、WPF中Command(命令)的四个概念: (1)命令command:要执行的动作。 (2)命令源command source:发出命令的对象(继承自ICommandSource)。 (3)命令目标command target:执行命令的主体 (4)命令绑定command binding:映射命令逻辑的对象 比如在上面示例中,粘贴(Paste)就是命令(command), 菜单项(MenuItem)是命令源(command source), 文本框(TextBox)是命令目标对象(command target), 命令绑定到command binding文本框(TextBox)控件上。
提示:WPF中的命令都继承自ICommand接口。ICommand暴露两个方法:Execute方法、 CanExecute方法和一个事件:CanExecuteChanged。 继承自ICommandSource的有:ButtonBase, MenuItem, Hyperlink和InputBinding。 而Button,GridViewColumnHeader,ToggleButton,RepeatButton继承自ButtonBase。System.Windows.Input.KeyBinding和MouseBinding继承自InputBinding。
2、四个小问题: (1)如何指定Command Sources? XAML:(请将“ApplicationCommands.Properties”换成对应的ApplicationCommands属性值,比如:ApplicationCommands.Copy) <StackPanel> <StackPanel.ContextMenu> <ContextMenu> <MenuItem Command="ApplicationCommands.Properties" /> </ContextMenu> </StackPanel.ContextMenu> </StackPanel>
同等的C#代码: StackPanel cmdSourcePanel = new StackPanel(); ContextMenu cmdSourceContextMenu = new ContextMenu(); MenuItem cmdSourceMenuItem = new MenuItem();
cmdSourcePanel.ContextMenu = cmdSourceContextMenu; cmdSourcePanel.ContextMenu.Items.Add(cmdSourceMenuItem);
cmdSourceMenuItem.Command = ApplicationCommands.Properties;
(2)如何指定快捷键?
XAML代码: <Window.InputBindings> <KeyBinding Key="B" Modifiers="Control" Command="ApplicationCommands.Open" /> </Window.InputBindings>
C#代码: KeyGesture OpenKeyGesture = new KeyGesture( Key.B, ModifierKeys.Control);
KeyBinding OpenCmdKeybinding = new KeyBinding(ApplicationCommands.Open,OpenKeyGesture); this.InputBindings.Add(OpenCmdKeybinding); //也可以这样(下面一句与上面两句的效果等同): //ApplicationCommands.Open.InputGestures.Add(OpenKeyGesture); (3)如何Command Binding? XAML代码: <Window.CommandBindings> <CommandBinding Command="ApplicationCommands.Open" Executed="OpenCmdExecuted" CanExecute="OpenCmdCanExecute"/> </Window.CommandBindings>
C#代码: CommandBinding OpenCmdBinding = new CommandBinding( ApplicationCommands.Open, OpenCmdExecuted, OpenCmdCanExecute);
this.CommandBindings.Add(OpenCmdBinding);
具体的事件处理: C#代码: void OpenCmdExecuted(object target, ExecutedRoutedEventArgs e) { MessageBox.Show("The command has been invoked."); }
void OpenCmdCanExecute(object sender, CanExecuteRoutedEventArgs e) { e.CanExecute = true; }
(4)如何设置Command Target并进行绑定Command Binding? XAML代码: <StackPanel> <Menu> <MenuItem Command="ApplicationCommands.Paste" CommandTarget="{Binding ElementName=mainTextBox}" /> </Menu> <TextBox Name="mainTextBox"/> </StackPanel> C#代码: StackPanel mainStackPanel = new StackPanel(); TextBox mainTextBox= new TextBox(); Menu stackPanelMenu = new Menu(); MenuItem pasteMenuItem = new MenuItem();
stackPanelMenu.Items.Add(pasteMenuItem); mainStackPanel.Children.Add(stackPanelMenu); mainStackPanel.Children.Add(mainTextBox);
pasteMenuItem.Command = ApplicationCommands.Paste;
以上例子全是单条命令绑定的情形,事实上,你也可以多个按钮多条命令绑定到同一控件上,比如: <StackPanel xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Orientation="Horizontal" Height="25"> <Button Command="Cut" CommandTarget="{Binding ElementName=textBoxInput}" Content="{Binding RelativeSource={RelativeSource Self}, Path=Command.Text}"/> <Button Command="Copy" CommandTarget="{Binding ElementName=textBoxInput}" Content="{Binding RelativeSource={RelativeSource Self}, Path=Command.Text}"/> <Button Command="Paste" CommandTarget="{Binding ElementName=textBoxInput}" Content="{Binding RelativeSource={RelativeSource Self}, Path=Command.Text}"/> <Button Command="Undo" CommandTarget="{Binding ElementName=textBoxInput}" Content="{Binding RelativeSource={RelativeSource Self}, Path=Command.Text}"/> <Button Command="Redo" CommandTarget="{Binding ElementName=textBoxInput}" Content="{Binding RelativeSource={RelativeSource Self}, Path=Command.Text}"/> <TextBox x:Name="textBoxInput" Width="200"/> </StackPanel>
最后,贴出一个完整点的例子:
XAML代码: <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="WPFCommand.Window1" Title="MenuItemCommandTask" x:Name="Window" Width="500" Height="400" > <Window.CommandBindings> <CommandBinding Command="ApplicationCommands.Open" Executed="OpenCmdExecuted" CanExecute="OpenCmdCanExecute"/> <CommandBinding Command="Help" CanExecute="HelpCanExecute" Executed="HelpExecuted" /> </Window.CommandBindings> <Window.InputBindings> <KeyBinding Command="Help" Key="F2" /> <KeyBinding Command="NotACommand" Key="F1" /> </Window.InputBindings> <Canvas> <Menu DockPanel.Dock="Top"> <MenuItem Command="ApplicationCommands.Paste" Width="75" /> </Menu> <TextBox BorderBrush="Black" BorderThickness="2" TextWrapping="Wrap" Text="这个TextBox未成为焦点之前,粘贴菜单不可用。" Width="476" Height="41" Canvas.Left="8" Canvas.Top="25"/> <Button Command="ApplicationCommands.Open" Height="32" Width="223" Content="测试弹出对话框" Canvas.Left="8" Canvas.Top="70"/> </Canvas> </Window>
对应的C#代码: using System; using System.IO; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Navigation;
namespace WPFCommand { public partial class Window1 { public Window1() { this.InitializeComponent(); } void OpenCmdExecuted(object target, ExecutedRoutedEventArgs e) { MessageBox.Show("测试弹出对话框,命令已执行!"); }
void OpenCmdCanExecute(object sender, CanExecuteRoutedEventArgs e) { e.CanExecute = true; }
void HelpCanExecute(object sender, CanExecuteRoutedEventArgs e) { e.CanExecute = true; }
void HelpExecuted(object sender, ExecutedRoutedEventArgs e) { System.Diagnostics.Process.Start("http://www.BrawDraw.com/"); } } }
你不妨试试在程序执行之后,按下F1或F2试试效果,是不是按F2时浏览器指向"http://www.BrawDraw.com/",而按F1时没有任何效果?这是因为这两句: <KeyBinding Command="Help" Key="F2" /> <KeyBinding Command="NotACommand" Key="F1" /> 当按F2时,Help命令执行;当按F1时,由于Command="NotACommand",即窗口忽略此命令的执行。
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