将SKSurface转换为SKBitmap，并在不同设备尺寸上将其调整为特定大小的图像 [英] Convert SKSurface to SKBitmap and resize into a image of a specific size on different device sizes

问题描述

我有一个Xamarin表单视图，根据触摸事件，我可以更改图像

I have a Xamarin forms view where based on touch events i can alter the image

 <StackLayout > 
        <skia:SKCanvasView x:Name="canvasView"
                           PaintSurface="ImageCanvas_PaintSurface"  
                           EnableTouchEvents="True" 
                           HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"
                           IgnorePixelScaling="True"// not sure if i need this??
                           Touch="OnTouch" />
        <Button Text="Generate Image" Clicked="CreateButton_Clicked"/>
    </StackLayout>

我需要根据在表面上绘制的图像生成准确的1060 x 550的图像

I need to generate a image of exactly 1060 x 550 based on what is drawn on the surface

 void ImageCanvas_PaintSurface(object sender, SKPaintSurfaceEventArgs args)
     {
            var surface = args.Surface;
            var canvas = surface.Canvas;

        /// paint bitmaps/text on canvas etc 


        // Save the image to local storage
        ViewModel.SaveImage(surface.Snapshot()); 
     }

到目前为止，我可以看到，如果我可以将从surface.Snapshot()返回的SKImage转换为SKBitmap，则可以使用Resize()函数.我该怎么做?

As far i can see If i could convert the SKImage which is returned from the surface.Snapshot() into a SKBitmap, I could use the Resize() function. How do i do this?

谢谢！

推荐答案

您可以拍照并将其另存为SKImage在设备文件夹中，然后将其作为流获取并调整大小并再次保存

You can take picture and save it as SKImage in device folder after that you get it as stream and resize it and re-save it again

        SKImage snapI = e.Surface.Snapshot();
        SKData pngImage = snapI.Encode();
        var x=  Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal), "FolderName");
        var fullpath = x+"PicName.png";
        File.WriteAllBytes(fullpath, pngImage.ToArray());
        SKBitmap bitmap = SKBitmap.Decode(fullpath);
        var dstInfo = new SKImageInfo(1060, 550);

        bitmap.Resize(dstInfo, SKBitmapResizeMethod.Hamming);

您可以根据需要进一步改善和优化代码.

You can ameliorate and optimize the code more as your needs.

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