UWP Dynamisches Rechteck erstellen

Question

Ich bin neu in UWP und meine erste Aufgabe ist crop imagine, jetzt versuche ich zu finden, wie kann ich ein dynamisches Rechteck zum Beschneiden erstellen imagine p.s. Es tut mir leid für die schlechte Grammatik.

Mein Programm muss, um die Datei zu öffnen, dann auf dem Bildschirm dynamisch Rechteck sein muss, die Benutzer bewegen ändern oder kann, und wenn drücken Benutzertaste Bild als Rechteck Größe wird Zuschneiden „Speichern“ ist mein C# -Code Danke)

namespace Crop1 
{ 
    public sealed partial class MainPage : Page 
    { 
     public MainPage() 
     { 
      this.InitializeComponent(); 
     } 

     SoftwareBitmap softwareBitmap; 
     private async void OpenFile(object sender, RoutedEventArgs e) 
     { 
      FileOpenPicker fileOpenPicker = new FileOpenPicker(); 
      fileOpenPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary; 
      fileOpenPicker.FileTypeFilter.Add(".jpg"); 
      fileOpenPicker.ViewMode = PickerViewMode.Thumbnail; 

      var inputFile = await fileOpenPicker.PickSingleFileAsync(); 

      if (inputFile == null) 
      { 
       // The user cancelled the picking operation 
       return; 
      } 

      using (IRandomAccessStream stream = await inputFile.OpenAsync(FileAccessMode.Read)) 
      { 
       // Create the decoder from the stream 
       BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream); 

       // Get the SoftwareBitmap representation of the file 
       softwareBitmap = await decoder.GetSoftwareBitmapAsync(); 
      } 
      if (softwareBitmap.BitmapPixelFormat != BitmapPixelFormat.Bgra8 || 
    softwareBitmap.BitmapAlphaMode == BitmapAlphaMode.Straight) 
      { 
       softwareBitmap = SoftwareBitmap.Convert(softwareBitmap, BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied); 
      } 

      var source = new SoftwareBitmapSource(); 
      await source.SetBitmapAsync(softwareBitmap); 

      // Set the source of the Image control 
      //imageControl.Source = source; 

      p1rect1.Fill = new ImageBrush 
      { 
       ImageSource = source 
      }; 
     } 

     private async void Save(object sender, RoutedEventArgs e) 
     { 
      FileSavePicker fileSavePicker = new FileSavePicker(); 
      fileSavePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary; 
      fileSavePicker.FileTypeChoices.Add("JPEG files", new List<string>() { ".jpg" , ".png"}); 
      fileSavePicker.SuggestedFileName = "image"; 

      var outputFile = await fileSavePicker.PickSaveFileAsync(); 

      if (outputFile == null) 
      { 
       // The user cancelled the picking operation 
       return; 
      } 
      // SoftwareBitmap softwareBitmap; 
      // BitmapDecoder decoder = await BitmapDecoder.CreateAsync(imageControl); 



      SaveSoftwareBitmapToFile(softwareBitmap, outputFile); 

     } 
     private async void SaveSoftwareBitmapToFile(SoftwareBitmap softwareBitmap, StorageFile outputFile) 
     { 
      using (IRandomAccessStream stream = await outputFile.OpenAsync(FileAccessMode.ReadWrite)) 
      { 
       // Create an encoder with the desired format 
       BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, stream); 

       // Set the software bitmap 
       encoder.SetSoftwareBitmap(softwareBitmap); 

       //// Set additional encoding parameters, if needed 
       //encoder.BitmapTransform.ScaledWidth = 320; 
       //encoder.BitmapTransform.ScaledHeight = 240; 
       // encoder.BitmapTransform.Rotation = Windows.Graphics.Imaging.BitmapRotation.Clockwise90Degrees; 
       encoder.BitmapTransform.InterpolationMode = BitmapInterpolationMode.Fant; 
       encoder.IsThumbnailGenerated = true; 

       try 
       { 
        await encoder.FlushAsync(); 
       } 
       catch (Exception err) 
       { 
        switch (err.HResult) 
        { 
         case unchecked((int)0x88982F81): //WINCODEC_ERR_UNSUPPORTEDOPERATION 
                 // If the encoder does not support writing a thumbnail, then try again 
                 // but disable thumbnail generation. 
          encoder.IsThumbnailGenerated = false; 
          break; 
         default: 
          throw err; 
        } 
       } 

       if (encoder.IsThumbnailGenerated == false) 
       { 
        await encoder.FlushAsync(); 
       } 


      } 
     } 
    } 
} 

Answer 1

Sie müssen ein dynamisches Rechteck erstellen, wenn sich der Mauszeiger bewegt. Sie können also für das Steuerelement "root panel" ein für den Zeiger relevantes Ereignis registrieren.

Dann können Sie mithilfe der RenderTargetBitmap-Klasse ein geclipptes Bild erstellen und speichern.

Ich habe ein Codebeispiel für Ihre Referenz gemacht:

<Canvas PointerMoved="Grid_PointerMoved" PointerReleased="Grid_PointerReleased" PointerPressed="Grid_PointerPressed"> 
    <Image x:Name="image"> 
    </Image> 
    <Rectangle x:Name="rect" StrokeThickness="4" Stroke="#FFEA18A7" Visibility="Collapsed"/> 
</Canvas> 

PointerPoint Point1, Point2; 
    SoftwareBitmap softwareBitmap; 
    private async void OpenFile() 
    { 
     FileOpenPicker fileOpenPicker = new FileOpenPicker(); 
     fileOpenPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary; 
     fileOpenPicker.FileTypeFilter.Add(".jpg"); 
     fileOpenPicker.ViewMode = PickerViewMode.Thumbnail; 

     var inputFile = await fileOpenPicker.PickSingleFileAsync(); 

     if (inputFile == null) 
     { 
      // The user cancelled the picking operation 
      return; 
     } 

     using (IRandomAccessStream stream = await inputFile.OpenAsync(FileAccessMode.Read)) 
     { 
      // Create the decoder from the stream 
      BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream); 

      // Get the SoftwareBitmap representation of the file 
      softwareBitmap = await decoder.GetSoftwareBitmapAsync(); 
     } 
     if (softwareBitmap.BitmapPixelFormat != BitmapPixelFormat.Bgra8 || 
softwareBitmap.BitmapAlphaMode == BitmapAlphaMode.Straight) 
     { 
      softwareBitmap = SoftwareBitmap.Convert(softwareBitmap, BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied); 
     } 

     var source = new SoftwareBitmapSource(); 
     await source.SetBitmapAsync(softwareBitmap); 

     image.Source = source; 
    } 

    private void Grid_PointerPressed(object sender, PointerRoutedEventArgs e) 
    { 
     Point1 = e.GetCurrentPoint(image); 
    } 

    private void Grid_PointerMoved(object sender, PointerRoutedEventArgs e) 
    { 
     Point2 = e.GetCurrentPoint(image); 
    } 

    private async void Grid_PointerReleased(object sender, PointerRoutedEventArgs e) 
    { 
     Point2 = e.GetCurrentPoint(image); 
     rect.Visibility = Visibility.Visible; 
     rect.Width = (int)Math.Abs(Point2.Position.X - Point1.Position.X); 
     rect.Height = (int)Math.Abs(Point2.Position.Y - Point1.Position.Y); 
     rect.SetValue(Canvas.LeftProperty, (Point1.Position.X < Point2.Position.X) ? Point1.Position.X : Point2.Position.X); 
     rect.SetValue(Canvas.TopProperty, (Point1.Position.Y < Point2.Position.Y) ? Point1.Position.Y : Point2.Position.Y); 
     await Task.Delay(100); 
     RectangleGeometry geometry = new RectangleGeometry(); 
     geometry.Rect = new Rect(Point1.Position,Point2.Position); 
     image.Clip = geometry; 
    } 

    private async void Save() 
    { 
     RenderTargetBitmap bitmap = new RenderTargetBitmap(); 
     await bitmap.RenderAsync(image); 
     var pixelbuffer = await bitmap.GetPixelsAsync(); 
     var savefolder = ApplicationData.Current.LocalFolder; 
     var savefile = await savefolder.CreateFileAsync("snapshot.png",CreationCollisionOption.GenerateUniqueName); 
     using (var filestream = await savefile.OpenAsync(FileAccessMode.ReadWrite)) 
     { 
      var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId,filestream); 
      encoder.SetPixelData(BitmapPixelFormat.Bgra8,BitmapAlphaMode.Ignore,(uint)bitmap.PixelWidth,(uint)bitmap.PixelHeight,DisplayInformation.GetForCurrentView().LogicalDpi,DisplayInformation.GetForCurrentView().LogicalDpi,pixelbuffer.ToArray()); 
      await encoder.FlushAsync(); 
     } 
    }