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我一直在尝试制作用户从 PhotoChooserTask 中选择的图片的副本，并将其用作我的应用程序中的 hubtile 的背景图像，但我无法找到更合适的方法来完成此操作。到目前为止，我可以将 hubtile 图像设置为 PhotoChooserTask_Completed 响应，但我不知道如何对位图执行复制操作，以便在再次启动或重新激活应用程序时保存此图像。到目前为止，我所拥有的如下：

我创建了一个自定义 TileItem 类来管理 HubTiles 的数据

TileItem.cs

public class TileItem
{
    //Old Implementation        
    //public string ImageUri  { get; set; }

    //New Implementation
    public BitmapImage ImageUri { get; set; }
    public string Title  { get; set; }
    public string Notification  { get; set; }
    public bool DisplayNotification
    {
        get { return !string.IsNullOrEmpty(this.Notification); }
    }

    public string Message  { get; set; }
    public string GroupTag   { get; set; }

    //for translation purposes (bound to HubTile Title on MainPage) 
    public string TileName  { get; set; }

MainPage.xaml.cs

PhotoChooserTask photoChooserTask;
TileItem tileItem;

public MainPage()
    {
        InitializeComponent();

        CreateHubTiles();

        photoChooserTask = new PhotoChooserTask();
        photoChooserTask.Completed += new EventHandler<PhotoResult>(photoChooserTask_Completed);
    }

接下来我创建瓷砖并使用自定义设置类来保存我的数据（即现在是位图的“ImageUri”）

public void CreateHubTiles()
    {            
        List<TileItem> tileItems = new List<TileItem>() 
        {
            new TileItem() { ImageUri = Settings.shareImage.Value, Title = "status", /*Notification = "last shared link uri",*/ Message = Settings.statusMessage.Value, GroupTag = "TileGroup", TileName = AppResource.Main_MainPage_HubTile_Status_Title },


            new TileItem() { ImageUri = Settings.linkImage.Value, Title = "link", /*Notification = "last shared status message",*/ Message = Settings.linkUri.Value, GroupTag = "TileGroup", TileName = AppResource.Main_MainPage_HubTile_Link_Title },
        };

        this.tileList.ItemsSource = tileItems;
    }

然后我负责 PhotoChooserTask 处理程序

public void changePictureMenuItem_Tap(object sender, System.Windows.Input.GestureEventArgs e)
    {
        var menuItem = (MenuItem)sender;
        tileItem = menuItem.DataContext as TileItem;  //used in PhotoChooserTask_Completed                

        try
        {
            photoChooserTask.Show();
        }
        catch (System.InvalidOperationException ex)
        {
            //MessageBox.Show("An error occurred");
            MessageBox.Show(AppResource.Main_MainPage_ContextMenu_ChangePicture_Error_Message);
        }
    }

    void photoChooserTask_Completed(object sender, PhotoResult e)
    {

        if (e.TaskResult == TaskResult.OK)
        {
            //BitmapImage bitmap = new BitmapImage();
            //bitmap.SetSource(e.ChosenPhoto);

            //get the correct tileItem that was clicked and set image source to respective hubtile
            string tileTitle = tileItem.Title.ToString();

            switch (tileTitle)
            {
                case "status":

                    tileItem.ImageUri.SetSource(e.ChosenPhoto);  //changes the hubtile image to selected image
                    //Settings.shareImage.Value.Equals(e.ChosenPhoto);

                    //Set the selected image to the shareImage bitmap in the Settings class to persist image
                    Settings.shareImage.Value.Equals(tileItem.ImageUri); //not working!                      
                    break;
                case "link":
                    //Same as above
                    tileItem.ImageUri.SetSource(e.ChosenPhoto);
                    //Settings.linkImage.Value.Equals(e.ChosenPhoto);
                    Settings.linkImage.Value.Equals(tileItem.ImageUri);
                    break;
            }

        }
        else if (e.TaskResult == TaskResult.Cancel)
            //MessageBox.Show("No picture was chosen - operation was cancelled", "Picture not chosen", MessageBoxButton.OK);
            MessageBox.Show(AppResource.Main_MainPage_ContextMenu_ChangePicture_TaskResultCancel_Message, AppResource.Main_MainPage_ContextMenu_ChangePicture_TaskResultCancel_Caption, MessageBoxButton.OK);
        else
            //MessageBox.Show("Error while choosing photo:\n" + e.Error.Message, "Fail", MessageBoxButton.OK);
            //MessageBox.Show("Error while choosing picture", "Fail", MessageBoxButton.OK);
            MessageBox.Show(AppResource.Main_MainPage_ContextMenu_ChangePicture_TaskResultError_Message, AppResource.Main_MainPage_ContextMenu_ChangePicture_TaskResultError_Caption, MessageBoxButton.OK);
    }

最初Settings.shareImage.Value和Settings.linkImage.value已设置，但不会在 PhotoChooserTask_Completed 事件中相应更改或更新。

设置.cs

public static readonly Setting<BitmapImage> shareImage = new Setting<BitmapImage>("shareImage", new BitmapImage(new Uri("/Images/shareStatusImage.jpg", UriKind.Relative)));

public static readonly Setting<BitmapImage> linkImage = new Setting<BitmapImage>("linkImage", new BitmapImage(new Uri("/Images/shareLinkImage.jpg", UriKind.Relative)));

因此，图像仅在应用程序未关闭时更新（在 PhotoChooserTask_Completed 事件中），然后在重新启动或激活时将它们设置回原始图像。如何相应地复制这些图像，以便从 PhotoChooserTask 中选择的图像可以永久用作ImageUri每个 TileItem 的新图像（根据我的第一个类，现在实际上是位图）？

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1 回答 1

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如果我对您的理解正确，您需要找到一种方法将拍摄的图像保存到隔离存储并在下次启动应用程序时加载。看看http://www.windowsphonegeek.com/tips/All-about-WP7-Isolated-Storage---Read-and-Save-Images，它包含保存和加载位图图像的完整代码

于 2012-08-18T10:08:33.443 回答