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我正在开发一个 WPF 应用程序并遵循 MVVM 方法。当用户单击“Enter”按钮时，我必须在我的登录屏幕上显示忙碌指示符，这意味着在进行身份验证时。在“Enter”按钮上，我有一个名为“EnterCommand”的 ICommand，它会检查身份验证，然后在身份验证成功时加载 MainWindow。

private ICommand _EnterCommand;
public ICommand EnterCommand
{
    get
    {
        return _EnterCommand ?? (_EnterCommand = new DelegateCommand(() =>
        {
            Thread objThread = new Thread(LoadApplication);
            objThread.SetApartmentState(ApartmentState.STA);
            objThread.Start();

        }));
    }
}

IsBusy 属性绑定到这个 showprogress

private bool _ShowProgress = false;
public bool ShowProgress
{
    get { return _ShowProgress; }
    set
    {
        if (_ShowProgress != value)
        {
            _ShowProgress = value;
            FirePropertyChanged("ShowProgress");
        }
    }
}

我正在这个命令上创建一个线程，然后从(bool Property name : ShowProgress)MVVM 设置 IsBusy 属性。

在加载应用程序中：

public void LoadApplication()
{
    ShowProgress= true;
    if (AuthenticateUser)
    {
        MainWindow objMainWindow = new MainWindow();
        objMainWindow.Show();
        Application.Current.MainWindow.Close();
    }
    ShowProgress= false;
}

Error: objMainWindow.Show()正在抛出错误 - 调用线程无法访问此对象，因为不同的线程拥有它。

同样在 App.xaml 中，我将 StartupUri 设置为我的“登录”窗口。

只要用户单击“Enter”按钮，就可以显示忙碌指示器，但是在显示主窗口时失败。

busyindicator只要我的MainWindow（即主屏幕）未启动，我就必须显示。

Error: objMainWindow.Show() in LoadApplication()正在抛出错误 - 调用线程无法访问此对象，因为不同的线程拥有它。

Stack Trace:
   at System.Windows.Markup.XamlReader.RewrapException(Exception e, Uri baseUri)
   at System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlReader templateReader, XamlObjectWriter currentWriter)
   at System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlObjectWriter objectWriter)
   at System.Windows.FrameworkTemplate.LoadOptimizedTemplateContent(DependencyObject container, IComponentConnector componentConnector, IStyleConnector styleConnector, List`1 affectedChildren, UncommonField`1 templatedNonFeChildrenField)
   at System.Windows.FrameworkTemplate.LoadContent(DependencyObject container, List`1 affectedChildren)
   at System.Windows.StyleHelper.ApplyTemplateContent(UncommonField`1 dataField, DependencyObject container, FrameworkElementFactory templateRoot, Int32 lastChildIndex, HybridDictionary childIndexFromChildID, FrameworkTemplate frameworkTemplate)
   at System.Windows.FrameworkTemplate.ApplyTemplateContent(UncommonField`1 templateDataField, FrameworkElement container)
   at System.Windows.FrameworkElement.ApplyTemplate()
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.StackPanel.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.Control.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.Grid.MeasureCell(Int32 cell, Boolean forceInfinityV)
   at System.Windows.Controls.Grid.MeasureCellsGroup(Int32 cellsHead, Size referenceSize, Boolean ignoreDesiredSizeU, Boolean forceInfinityV)
   at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
   at System.Windows.Controls.ContentPresenter.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Documents.AdornerDecorator.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Controls.Border.MeasureOverride(Size constraint)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Window.MeasureOverrideHelper(Size constraint)
   at System.Windows.Window.MeasureOverride(Size availableSize)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.Interop.HwndSource.SetLayoutSize()
   at System.Windows.Interop.HwndSource.set_RootVisualInternal(Visual value)
   at System.Windows.Interop.HwndSource.set_RootVisual(Visual value)
   at System.Windows.Window.SetRootVisual()
   at System.Windows.Window.SetRootVisualAndUpdateSTC()
   at System.Windows.Window.SetupInitialState(Double requestedTop, Double requestedLeft, Double requestedWidth, Double requestedHeight)
   at System.Windows.Window.CreateSourceWindow(Boolean duringShow)
   at System.Windows.Window.CreateSourceWindowDuringShow()
   at System.Windows.Window.SafeCreateWindowDuringShow()
   at System.Windows.Window.ShowHelper(Object booleanBox)
   at System.Windows.Window.Show()
   at RBS.MIB.DS.Reporting.UI.MainViewModelStartupWindow.LoadApplication() in C:\DSReporting\trunk\Projects\csharp\UI\RBS.MIB.DS.Reporting.UI\StartUpWindow\StartupViewModel\MainViewModelStartupWindow.cs:line 104
   InnerException: System.InvalidOperationException
   Message=The calling thread cannot access this object because a different thread owns it.
4

1 回答 1

1

Please try this:

private BackgroundWorker _BgWorker;

public LoginFormViewModel()
{
    _BgWorker = new BackgroundWorker();
    _BgWorker.DoWork += new DoWorkEventHandler(bgw_DoWork);
    _BgWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bgw_RunWorkerCompleted);
    _BgWorker.ProgressChanged += new ProgressChangedEventHandler(bgw_ProgressChanged);
    _BgWorker.RunWorkerAsync();
}

void bgw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    // write your code to check authentication
}

void bgw_DoWork(object sender, DoWorkEventArgs e)
{
   // write you code to open window
}

void bgw_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    // write the code for busy indicator like 
    ShowProgress= true;
}

Hope this may help you.

于 2013-06-26T10:46:01.490 回答