如何使用MVVM模式实现进度条

  • Z时代
  • 2024-01-10
  • 分类：问答

我有一个基于MVVM设计模式的WPF应用程序。

我希望在应用程序中实现一个遵循MVVM模式的进度条。

有没有人对如何实现这一建议？

提前致谢

回答：

通常，您的UI会简单地绑定到VM中的属性：

<ProgressBar Value="{Binding CurrentProgress, Mode=OneWay}" 
             Visibility="{Binding ProgressVisibility}"/>

您的VM将使用a BackgroundWorker在后台线程上进行工作，并定期更新该CurrentProgress值。像这样：

public class MyViewModel : ViewModel
{
    private readonly BackgroundWorker worker;
    private readonly ICommand instigateWorkCommand;
    private int currentProgress;
    public MyViewModel()
    {
        this.instigateWorkCommand = 
                new DelegateCommand(o => this.worker.RunWorkerAsync(), 
                                    o => !this.worker.IsBusy);
        this.worker = new BackgroundWorker();
        this.worker.DoWork += this.DoWork;
        this.worker.ProgressChanged += this.ProgressChanged;
    }
    // your UI binds to this command in order to kick off the work
    public ICommand InstigateWorkCommand
    {
        get { return this.instigateWorkCommand; }
    }
    public int CurrentProgress
    {
        get { return this.currentProgress; }
        private set
        {
            if (this.currentProgress != value)
            {
                this.currentProgress = value;
                this.OnPropertyChanged(() => this.CurrentProgress);
            }
        }
    }
    private void DoWork(object sender, DoWorkEventArgs e)
    {
        // do time-consuming work here, calling ReportProgress as and when you can
    }
    private void ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        this.CurrentProgress = e.ProgressPercentage;
    }
}

以上是 如何使用MVVM模式实现进度条 的全部内容， 来源链接： utcz.com/qa/419115.html

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