c# - 如何在 TextBlock 中显示变化的时间？

Question

所以我有一个秒表，我只想将它显示在文本 block 上。我该怎么做？

Answer 1

创建一个 TimerViewModel，看起来像这样:

public class TimerViewModel : INotifyPropertyChanged
{
    public TimerViewModel()
    {
        timer = new DispatcherTimer();
        timer.Interval = TimeSpan.FromSeconds(1);
        timer.Tick += new EventHandler(timer_Tick);
        timer.Start();
        startTime = DateTime.Now;
    }

    private DispatcherTimer timer;
    private DateTime startTime;
    public event PropertyChangedEventHandler PropertyChanged;
    public TimeSpan TimeFromStart { get { return DateTime.Now - startTime; } }

    private void timer_Tick(object sender, EventArgs e)
    {
        RaisePropertyChanged("TimeFromStart");
    }

    private void RaisePropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

在您的代码隐藏中像这样实例化它:

public partial class TimerPage : UserControl
{
    public TimerPage()
    {
        InitializeComponent();
        timerViewModel = new TimerViewModel();
        DataContext = timerViewModel;
    }

    private TimerViewModel timerViewModel;
}

然后像这样绑定(bind)它:

<Grid x:Name="LayoutRoot" Background="White">
    <TextBlock Text="{Binding TimeFromStart}" />
</Grid>

像魅力一样工作。我敢肯定，您需要稍微修改基本概念，但让 DispatcherTimer 触发 PropertyChanged 通知的基本思想才是关键。