c# - 简单的闪烁文本

Question

我正在尝试使用 C#/WPF 中尽可能少的代码来构建一个闪烁“Hello World”文本的简单演示项目。我写的编译和运行，但实际上并没有使文本闪烁(它基于每 2 秒触发一次并更改标签可见性的计时器。关于为什么文本不闪烁或更有效的方法的任何想法方法是什么？代码:

using System;
using System.Timers;
using System.Windows;

namespace BlinkingText
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        static Timer _timer;
        static MainWindow window = new MainWindow();

    public MainWindow()
    {
        InitializeComponent();

        Start();
    }

    public static void Start()
    {
        var timer = new Timer(2000);
        timer.Elapsed += new ElapsedEventHandler(_timer_Elapsed);
        timer.Enabled = true;
        _timer = timer;
    }

    public static void _timer_Elapsed(object sender, ElapsedEventArgs e)
    {

        if (window.HelloWorldLabel.Visibility == Visibility.Hidden)
        {
            Application.Current.Dispatcher.Invoke((Action)delegate
            {
                window.HelloWorldLabel.Visibility = Visibility.Visible;
            });
        }
        else
        {
            Application.Current.Dispatcher.Invoke((Action)delegate
            {
                window.HelloWorldLabel.Visibility = Visibility.Hidden;
            });
      }
    }
  }
}

Answer 1

应用程序中的文本不会闪烁，因为您在隐藏的 MainWindow 实例中更改了标签的可见性，这与您在屏幕上看到的不一样。

创建者

static MainWindow window = new MainWindow();

但从未显示。

除此之外，您应该像这样使用 DispatcherTimer:

public partial class MainWindow : Window
{
    private readonly DispatcherTimer timer =
        new DispatcherTimer { Interval = TimeSpan.FromSeconds(2) };

    public MainWindow()
    {
        InitializeComponent();

        timer.Tick += Timer_Tick;
        timer.Start();
    }

    private void Timer_Tick(object sender, EventArgs e)
    {
        HelloWorldLabel.Visibility = HelloWorldLabel.Visibility == Visibility.Visible
            ? Visibility.Hidden : Visibility.Visible;
    }
}

---

您也可以完全在 XAML 中执行类似的操作，例如像这样:

<TextBlock Text="Hello, World.">
    <TextBlock.Triggers>
        <EventTrigger RoutedEvent="Loaded">
            <BeginStoryboard>
                <Storyboard>
                    <ObjectAnimationUsingKeyFrames
                        Storyboard.TargetProperty="Visibility"
                        Duration="0:0:4" RepeatBehavior="Forever">

                        <DiscreteObjectKeyFrame
                            KeyTime="0:0:0"
                            Value="{x:Static Visibility.Visible}"/>
                        <DiscreteObjectKeyFrame
                            KeyTime="0:0:2"
                            Value="{x:Static Visibility.Hidden}"/>
                    </ObjectAnimationUsingKeyFrames>
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger>
    </TextBlock.Triggers>
</TextBlock>