WPF立即更改圖像源

Question

我已經設法解決了如何以編程方式更改WPF窗體中的圖像，但我真的很努力解決如何立即執行此操作。我有一個在多個進程的進展報告的GUI，下面的代碼工作，以改變形象：

cacheBuilderStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox-complete.png")); 

但這並不即時更新的形象，我很茫然如何，我力重繪GUI。我已經試過這兩個但又似乎都不產生任何影響：

 cacheBuilderStatus.InvalidateVisual(); 
     cacheBuilderStatus.UpdateLayout(); 

我甚至想這無濟於事：

 BitmapImage cbImage = new BitmapImage(); //(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     cbImage.BeginInit(); 
     cbImage.CacheOption = BitmapCacheOption.None; 
     cbImage.UriCachePolicy = new System.Net.Cache.RequestCachePolicy(System.Net.Cache.RequestCacheLevel.BypassCache); 
     cbImage.CacheOption = BitmapCacheOption.OnLoad; 
     cbImage.CreateOptions = BitmapCreateOptions.IgnoreImageCache; 
     cbImage.UriSource = new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png"); 
     cbImage.EndInit(); 

如果有人可以幫助我瞭解如何做到這一點，我會非常感謝。

謝謝。

編輯：有問題的圖像的XAML是：

  <Image x:Name="cacheBuilderStatus" Grid.Row="0" Grid.Column="3" HorizontalAlignment="Center" Width="20" Source="Resources/checkbox.png"/> 

，並在後臺的代碼如下所示：

 // Reset progress images 
    private void resetStatus() 
    { 
     BitmapImage cbImage = new BitmapImage(); //(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     cbImage.BeginInit(); 
     cbImage.CacheOption = BitmapCacheOption.None; 
     cbImage.UriCachePolicy = new System.Net.Cache.RequestCachePolicy(System.Net.Cache.RequestCacheLevel.BypassCache); 
     cbImage.CacheOption = BitmapCacheOption.OnLoad; 
     cbImage.CreateOptions = BitmapCreateOptions.IgnoreImageCache; 
     cbImage.UriSource = new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png"); 
     cbImage.EndInit(); 

     cacheBuilderStatus.InvalidateVisual(); 
     cacheBuilderStatus.UpdateLayout(); 

     cacheBuilderStatus.Source = cbImage; 
     ciUserStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     accessCiUserStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     configItemStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     enumerationsStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     serviceOfferingStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     workItemStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     websiteStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
     appPoolStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox.png")); 
    } 


    // Buttons event handlers 
    // Restart portal 
    private void primaryToggleButton_Checked(object sender, RoutedEventArgs e) 
    { 
     // Result variables 
     string serviceRestartResult; 
     bool cIUserResult; 
     bool accessUserWIResult; 
     bool configurationItemsResult; 
     bool enumerationResult; 
     bool serviceOfferingResult; 
     bool workItemResult; 
     string websiteRestartResult; 
     string appPoolRestartResult; 

     // Pull timeout variables from app.config 
     serviceStatusChangeTimeout = Int32.Parse(ConfigurationManager.AppSettings.Get("serviceStatusChangeTimeout")); 
     websiteStatusChangeTimeout = Int32.Parse(ConfigurationManager.AppSettings.Get("websiteStatusChangeTimeout")); 

     // Get current DateTIme for LastModified tests 
     DateTime time = DateTime.Now.ToUniversalTime(); 


     // Reset status images 
     resetStatus(); 
     Thread.Sleep(5000); 

     // Service restart 
     serviceRestartResult = MidTier.ServiceRestart(serviceStatusChangeTimeout); 
     if (serviceRestartResult == "Success") 
     { 
      // If success set service status icon to completed image 
      cacheBuilderStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox-complete.png")); 
     } 
     else 
     { 
      // If fail set image to failed red cross, display error text and error text margin to 5 and height to Auto. 
      cacheBuilderStatus.Source = new BitmapImage(new Uri("pack://application:,,,/WpfCustomControlLibrary1;component/Resources/checkbox-error.png")); 
      displayErrorText(serviceRestartResult); 
     } 

Answer 1

您的代碼來改變圖像看起來很好，並應立即更新。我認爲你的問題在於你在UI線程上處理了一些信息，因此它不會更新。

您的處理應該始終移動到後臺線程，否則您將鎖定UI線程直到完成並且無法更新。

例如，如果你這樣做：

private void button_Click(object sender, RoutedEventArgs e) 
{ 
    myImage.Source = new BitmapImage(new Uri(@"e:\icons\transfer1.ico")); 
} 

它會立刻更新。但是，如果你在那裏做處理喜歡所以它不會：

private void button_Click(object sender, RoutedEventArgs e) 
{ 
    myImage.Source = new BitmapImage(new Uri(@"e:\icons\transfer1.ico")); 
    Thread.Sleep(5000); //simulate doing stuff 
} 

因此，而不是做處理在不同的線程像這樣：

private async void button_Click(object sender, RoutedEventArgs e) 
{ 
    myImage.Source = new BitmapImage(new Uri(@"e:\icons\transfer1.ico")); 

    await Task.Run(() => 
     { 
      //Do work here 
      Thread.Sleep(5000); 
     }); 
}