Windows 8实用窍门系列：16.Windows 8的右键菜单

　　在Windows 8中的控件中有TextBox等输入控件的ContextMenuOpening事件和Button等非输入控件的RightTapped事件。

　　本文中将讲述者两个事件的用法。这两个事件的

　　PopupMenu是右键弹出菜单的具体类。

　　首先我们看具体菜单类的实例化和获取项目代码

/// <summary>
/// 设置右键点击点击具体处理细节
/// </summary>
/// <param name="sender"></param>
public async void SetRightClick(object sender)
{
//增加菜单
PopupMenu menu = new PopupMenu();
menu.Commands.Add(new UICommand("复制0", null, 0));
menu.Commands.Add(new UICommand("剪切1", null, 1));
menu.Commands.Add(new UICommand("粘贴2", null, 2));
menu.Commands.Add(new UICommandSeparator());
menu.Commands.Add(new UICommand("Full Screen", null, 3));
menu.Commands.Add(new UICommand("Snap Screen", null, 4));
//获取选择的菜单项
var cmd = await menu.ShowForSelectionAsync(GetRectPosition((FrameworkElement)sender));
if (cmd != null)
{
switch ((int)cmd.Id)
{
case 0:
tbText.Text = "选择了（" + cmd.Label + "） ,其ID为" + cmd.Id;
break;
case 1:
tbText.Text = "选择了（" + cmd.Label + "）,其ID为" + cmd.Id;
break;
case 2:
tbText.Text = "选择了（" + cmd.Label + "） ,其ID为" + cmd.Id;
break;
case 3:
tbText.Text = "选择了（" + cmd.Label + "） ,其ID为" + cmd.Id;
break;
case 4:
tbText.Text = "选择了（" + cmd.Label + "） ,其ID为" + cmd.Id;
break;
}
}
else
{
tbText.Text = "上下文菜单";
}
}
//获取菜单位置
Rect GetRectPosition(FrameworkElement element)
{
GeneralTransform btnform = element.TransformToVisual(null);
Point point = btnform.TransformPoint(new Point());
return new Rect(point, new Size(element.ActualWidth, element.ActualHeight));
}

　　然后我们看看注册两个控件的右键处理事件如下：

/// <summary>
/// Invoked when this page is about to be displayed in a Frame.
/// </summary>
/// <param name="e">Event data that describes how this page was reached.  The Parameter
/// property is typically used to configure the page.</param>
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
//上下文菜单
this.tbName.ContextMenuOpening += tbName_ContextMenuOpening;
//右键菜单
this.gdMenu.RightTapped += gdMenu_RightTapped;
}

/// <summary>
/// 右键菜单事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void gdMenu_RightTapped(object sender, RightTappedRoutedEventArgs e)
{
SetRightClick(sender);
}

/// <summary>
/// 上下文菜单
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void tbName_ContextMenuOpening(object sender, ContextMenuEventArgs e)
{
SetRightClick(sender);
}

/// <summary>
/// 事件卸载
/// </summary>
/// <param name="e"></param>
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
base.OnNavigatedFrom(e);
//上下文菜单
this.tbName.ContextMenuOpening -= tbName_ContextMenuOpening;
//右键菜单
this.gdMenu.RightTapped -= gdMenu_RightTapped;
}

　　再次看看前台Xaml代码如下：

<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}" Name="gdMenu">
<TextBox HorizontalAlignment="Left" Margin="141,164,0,0" TextWrapping="Wrap"
Name="tbName" Text="" VerticalAlignment="Top" Height="157" Width="540"/>
<TextBox HorizontalAlignment="Left" Margin="210,353,0,0" TextWrapping="Wrap"
Name="tbText" Text="" VerticalAlignment="Top" Width="290"/>
</Grid>

　　如需源码请点击 Win8Menu.rar 下载,下面是效果图.