Windows Phone 8.1 中的文件選取器

Question

我想從 Windows Phone 8.1 的相冊中選擇一張圖片。 為此，我使用了這段代碼，但它給出了錯誤

private async void gallery_Tapped(object sender, TappedRoutedEventArgs e)
        {
            FileOpenPicker opener = new FileOpenPicker();
            opener.ViewMode = PickerViewMode.Thumbnail;
            opener.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
            opener.FileTypeFilter.Add(".jpg");
            opener.FileTypeFilter.Add(".jpeg");
            opener.FileTypeFilter.Add(".png");

            StorageFile file = await opener.PickSingleFileAsync();
            if (file != null)
            {
                // We've now got the file. Do something with it.
                var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
                var bitmapImage = new Windows.UI.Xaml.Media.Imaging.BitmapImage();
                await bitmapImage.SetSourceAsync(stream);

                var decoder = await               Windows.Graphics.Imaging.BitmapDecoder.CreateAsync(stream);
                MyImage.Source=bitmapImage;
            }
            else
            {
                //OutputTextBlock.Text = "The operation may have been cancelled.";
            }
        }

錯誤

Answer 1

我認為您甚至可以在您需要的頁面中處理 OnActivated 事件。 像這樣的東西

CoreApplicationView view = CoreApplication.GetCurrentView();

ImagePath=string.Empty;
FileOpenPicker filePicker = new FileOpenPicker();
filePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
filePicker.ViewMode = PickerViewMode.Thumbnail;

// Filter to include a sample subset of file types
filePicker.FileTypeFilter.Clear();
filePicker.FileTypeFilter.Add(".bmp");
filePicker.FileTypeFilter.Add(".png");
filePicker.FileTypeFilter.Add(".jpeg");
filePicker.FileTypeFilter.Add(".jpg");

filePicker.PickSingleFileAndContinue();
view.Activated += viewActivated; 

private void viewActivated(CoreApplicationView sender, IActivatedEventArgs args1)
{
    FileOpenPickerContinuationEventArgs args = args1 as FileOpenPickerContinuationEventArgs;

    if (args != null)
    {
        if (args.Files.Count == 0) return;

        view.Activated -= viewActivated;
        storageFileWP = args.Files[0];

    }
}

當您從選擇器中選擇文件時，將調用上述方法。 我相信它對你有幫助。

Answer 2

在 Windows Phone 8.1 中使用 FileOpenPicker 從圖片庫中選擇圖片。

步驟 1：在您的 Windows Phone 8.1 應用程序中添加圖片庫功能。

第 2 步：添加 File Open Picker 作為聲明。

步驟 3：向 MainPage.xaml 添加按鈕和圖像。

<Grid>
<Image Name="img"/>
<Button Content="click me" Click="Button_Click"/>
</Grid>

第四步：添加全局變量視圖。

CoreApplicationView view;

步驟 4.1 在頁面構造函數中初始化。

view = CoreApplication.GetCurrentView();

第 5 步：添加代碼以在按鈕單擊事件上調用文件打開選擇器。

private void Button_Click(object sender, RoutedEventArgs e)
{
    FileOpenPicker filePicker = new FileOpenPicker();
    filePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
    filePicker.ViewMode = PickerViewMode.Thumbnail;

    // Filter to include a sample subset of file types
    filePicker.FileTypeFilter.Clear();
    filePicker.FileTypeFilter.Add(".bmp");
    filePicker.FileTypeFilter.Add(".png");
    filePicker.FileTypeFilter.Add(".jpeg");
    filePicker.FileTypeFilter.Add(".jpg");

    filePicker.PickSingleFileAndContinue();
    view.Activated += viewActivated; 
}

第 6 步：在 View 激活事件上將圖像設置為 MainPage。

private async void viewActivated(CoreApplicationView sender, IActivatedEventArgs args1)
{
  FileOpenPickerContinuationEventArgs args = args1 as FileOpenPickerContinuationEventArgs;

  if (args != null)
  {
      if (args.Files.Count == 0) return;

      view.Activated -= viewActivated;
      StorageFile storageFile = args.Files[0];
      var stream = await storageFile.OpenAsync(Windows.Storage.FileAccessMode.Read);
      var bitmapImage = new Windows.UI.Xaml.Media.Imaging.BitmapImage();
      await bitmapImage.SetSourceAsync(stream);

      var decoder = await Windows.Graphics.Imaging.BitmapDecoder.CreateAsync(stream);
      img.Source=bitmapImage;
  }
}

它還允許您拍照並使用它。

參考： 在 Windows Phone 8.1 中使用 FileOpenPicker 從圖片庫中選擇圖片

Answer 3

使用 RoutedEventArgs 而不是 TappedRoutedEventArgs 在 wp 8.1 xaml 中單擊按鈕 不要使用 async 關鍵字

 private void OpenImageFile(object sender, RoutedEventArgs e) { FileOpenPicker filePicker = new FileOpenPicker(); filePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary; filePicker.ViewMode = PickerViewMode.Thumbnail; // Filter to include a sample subset of file types filePicker.FileTypeFilter.Clear(); filePicker.FileTypeFilter.Add(".bmp"); filePicker.FileTypeFilter.Add(".png"); filePicker.FileTypeFilter.Add(".jpeg"); filePicker.FileTypeFilter.Add(".jpg"); filePicker.PickSingleFileAndContinue(); view.Activated += viewActivated; } private void viewActivated(CoreApplicationView sender, IActivatedEventArgs args1) { FileOpenPickerContinuationEventArgs args = args1 as FileOpenPickerContinuationEventArgs; if (args != null) { if (args.Files.Count == 0) return; view.Activated -= viewActivated; StorageFile SelectedImageFile = args.Files[0]; } }

• 並使用 CoreApplicationView 視圖； 類中每個方法之外的任何位置作為全局
• 不要忘記使用 view = CoreApplication.GetCurrentView(); 在 InitializeComponent() 之后的相關頁面類的構造函數內； 方法

我認為這會有所幫助:) 謝謝

Answer 4

var fill = await StorageFile.GetFileFromPathAsync(selectItem.FolderPath); BitmapImage bit = new BitmapImage();

                    if (fill != null)
                    {
                        // We've now got the file. Do something with it.
                        var stream = await fill.OpenAsync(Windows.Storage.FileAccessMode.Read);
                        //var bitmapImage = new Windows.UI.Xaml.Media.Imaging.BitmapImage();
                        //await bitmapImage.SetSourceAsync(stream);
                        bit.SetSource(stream);
                        imgTeste.Source = bit;
                        pvMestre.SelectedIndex = 1;
                    }
                    else
                    {
                        //OutputTextBlock.Text = "The operation may have been cancelled.";
                    }