我正在使用自己的类,派生自ContentControl(我们称之为MyControl)我希望用户能够为我的控件订阅KeyDown和KeyUp事件。
我遇到的问题是MyControl似乎没有收到任何关键事件。我推断这可能是一个焦点问题。例如,如果我向项目添加一个按钮,以编程方式将焦点设置在MyControl上,那么我将开始接收这些事件。问题是,只要我点击任何地方,包括我自己的控制,它似乎失去焦点(无论哪种方式,键不再工作)。我无法通过单击任何一个来恢复它,但似乎我必须使用MyControl.Focus方法。
所以,我的问题是:如何通过点击它来使控件能够接受焦点?
另外,为了您的乐趣,我在下面添加了一个小样本项目来演示我遇到的问题:
MainPage.xaml中
<Page
x:Class="Focus.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Focus"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="300"/>
</Grid.ColumnDefinitions>
<Grid x:Name="BG">
</Grid>
<StackPanel Grid.Column="1" Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<Button Content="Focus" Click="FocusClick"/>
</StackPanel>
<TextBlock x:Name="InfoText" FontSize="16" TextWrapping="Wrap" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
</StackPanel>
</Grid>
</Page>
MainPage.xaml.cs中
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
namespace Focus
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
public static MainPage Current;
public MyControl ctrl;
public MainPage()
{
this.InitializeComponent();
Current = this;
ctrl = new MyControl();
BG.Children.Add(ctrl);
ctrl.KeyDown += ctrl_KeyDown;
ctrl.KeyUp += ctrl_KeyUp;
}
void ctrl_KeyUp(object sender, KeyRoutedEventArgs e)
{
ShowInfo("Pressed " + e.Key);
}
private void ctrl_KeyDown(object sender, KeyRoutedEventArgs e)
{
ShowInfo("Released " + e.Key);
}
/// <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)
{
}
public void ShowInfo(string text)
{
InfoText.Text = text + Environment.NewLine + InfoText.Text;
}
private void FocusClick(object sender, RoutedEventArgs e)
{
ctrl.Focus(FocusState.Programmatic);
}
}
}
MyControl.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Foundation;
using Windows.UI;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Shapes;
using Windows.UI.Xaml;
namespace Focus
{
public class MyControl : ContentControl
{
public MyControl()
: base()
{
LinearGradientBrush lb = new LinearGradientBrush();
lb.StartPoint = new Point(0, 0);
lb.EndPoint = new Point(1, 1);
lb.GradientStops.Add(new GradientStop() { Color = Colors.Red, Offset = 0, });
lb.GradientStops.Add(new GradientStop() { Color = Colors.Yellow, Offset = 1, });
Rectangle rect = new Rectangle();
rect.Width = 800;
rect.Height = 1000;
rect.Fill = lb;
this.Content = rect;
}
}
}
这是通过名为Focus的空白项目完成的。 上面的3个文件分别是MainPage.xaml,MainPage.xaml.cs和MyControl.cs。
答案 0 :(得分:0)
我已经运行了您的示例,看起来WinRT中存在一些错误,您可以阅读此MSDN Thread。作为一种变通方法,您可以添加对您的控件LostFocus
事件的订阅:
ctrl.LostFocus += ctrl_LostFocus;
void ctrl_LostFocus(object sender, RoutedEventArgs e)
{
((MyControl)sender).Focus(FocusState.Programmatic);
}
每次丢失时手动将焦点设置到控件上。 但对我而言,这是一个糟糕的解决方案,因为你的控制权总是会集中精力。当然,您可以扩展此方法以提供一些额外的逻辑。