使用捏来放大和缩小一些不需要的背景应该复制的颜色出现并且像素质量低 android 低于 9 版本 Xamarin android [英] Using pinch to zoomin and zoomout some unwanted background should copied color appeared and pixel quality low android below 9 version Xamarin android

问题描述

每当我使用两个手指捏合来放大和缩小时，一些不需要的背景应该复制的颜色出现我的相机页面渲染器，如果我单点触摸或触摸它似乎在我捏合时没有出现用两根手指放大它出现在我的屏幕上

Whenever i using wo fingers pinch to zoomin and zoomout some unwanted background should copied color appeared my camerapagerenderer if i single touch or touch it not seems to be apppear when i pinch to zoomin using two fingers it appears on my screen

    public override bool OnTouchEvent(MotionEvent e)
            {
                
                switch (e.Action & MotionEventActions.Mask)
                {
                    case MotionEventActions.Down:
                        oldDist = getFingerSpacing(e);
                        break;
                    case MotionEventActions.Move:
                        float newDist = getFingerSpacing(e);
                        if (newDist > oldDist)
                        {
                            //mCamera is your Camera which used to take picture, it should already exit in your custom Camera
                            handleZoom(true, camera);
                        }
                        else if (newDist < oldDist)
                        {
                            handleZoom(false, camera);
                        }
                        oldDist = newDist;
                        break;
                }
                return true;
            }
    
    private void handleZoom(bool isZoomIn, global::Android.Hardware.Camera camera)
            {
                global::Android.Hardware.Camera.Parameters parameters = camera.GetParameters();
                if (parameters.IsZoomSupported)
                {
                    int maxZoom = parameters.MaxZoom;
                    int zoom = parameters.Zoom;
                    
                    if (isZoomIn && zoom < maxZoom)
                    {
                        zoom++;
                    }
                    else if(zoom > 0)
                    {
                        zoom--;
                    }
                    parameters.Zoom = zoom;
                    camera.SetParameters(parameters);
                }
                else
                {
                    Android.Util.Log.Error("lv", "zoom not supported");
                }
            }
        private static float getFingerSpacing(MotionEvent e)
            {
         if(e.PointerCount==2)
    {
               int pointerIndex = e.FindPointerIndex(_activePointerId);
                float x = e.GetX(pointerIndex);
                float y = e.GetY(pointerIndex);
        return (float)Math.Sqrt(x * x + y * y);
    }
        }

推荐答案

您可以查看下面的代码.它适用于 Android 10.0，没有色调.

You could check the code below. It works on Android 10.0 with no color shades.

 class CameraPageRenderer : PageRenderer, TextureView.ISurfaceTextureListener
{
    global::Android.Hardware.Camera camera;
    global::Android.Widget.Button takePhotoButton;
    global::Android.Widget.Button toggleFlashButton;
    global::Android.Widget.Button switchCameraButton;
    global::Android.Views.View view;

    Activity activity;
    CameraFacing cameraType;
    TextureView textureView;
    SurfaceTexture surfaceTexture;

    bool flashOn;

    public CameraPageRenderer(Context context) : base(context)
    {
    }

    float oldDist = 1f;
    public override bool OnTouchEvent(MotionEvent e)
    {

        switch (e.Action & MotionEventActions.Mask)
        {
            case MotionEventActions.Down:
                oldDist = getFingerSpacing(e);
                break;
            case MotionEventActions.Move:
                float newDist = getFingerSpacing(e);
                if (newDist > oldDist)
                {
                    //mCamera is your Camera which used to take picture, it should already exit in your custom Camera
                    handleZoom(true, camera);
                }
                else if (newDist < oldDist)
                {
                    handleZoom(false, camera);
                }
                oldDist = newDist;
                break;
        }
        return true;
    }
    private static float getFingerSpacing(MotionEvent e)
    {
        if (e.PointerCount == 2)
        {
            float x = e.GetX(0) - e.GetX(1);
            float y = e.GetY(0) - e.GetY(1);
            return (float)Math.Sqrt(x*x + y*y);
        }

        return 0;
    }

    private void handleZoom(bool isZoomIn, global::Android.Hardware.Camera camera)
    {
        //camera.StopPreview();
        //  camera.Release();
        // camera = global::Android.Hardware.Camera.Open((int)cameraType);
        global::Android.Hardware.Camera.Parameters parameters = camera.GetParameters();
        if (parameters.IsZoomSupported)
        {
            int maxZoom = parameters.MaxZoom;
            int zoom = parameters.Zoom;

            if (isZoomIn && zoom < maxZoom)
            {
                zoom++;
            }
            else if (zoom > 0)
            {
                zoom--;
            }
            parameters.Zoom = zoom;
            camera.SetParameters(parameters);
            camera.SetPreviewTexture(surfaceTexture);
            PrepareAndStartCamera();
        }
        else
        {
            Android.Util.Log.Error("lv", "zoom not supported");
        }
    }


    protected override void OnElementChanged(ElementChangedEventArgs<Page> e)
    {
        base.OnElementChanged(e);
        if (e.OldElement != null || Element == null)
        {
            return;
        }

        try
        {
            SetupUserInterface();
            //SetupEventHandlers();
            AddView(view);
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine(@"           ERROR: ", ex.Message);
        }
    }

    void SetupUserInterface()
    {
        activity = this.Context as Activity;
        view = activity.LayoutInflater.Inflate(Resource.Layout.CameraLayout, this, false);
        cameraType = CameraFacing.Back;

        textureView = view.FindViewById<TextureView>(Resource.Id.textureView);
        textureView.SurfaceTextureListener = this;
    }

   
    protected override void OnLayout(bool changed, int l, int t, int r, int b)
    {
        base.OnLayout(changed, l, t, r, b);
        var msw = MeasureSpec.MakeMeasureSpec(r - l, MeasureSpecMode.Exactly);
        var msh = MeasureSpec.MakeMeasureSpec(b - t, MeasureSpecMode.Exactly);

        view.Measure(msw, msh);
        view.Layout(0, 0, r - l, b - t);
    }

    public void OnSurfaceTextureAvailable(SurfaceTexture surface, int width, int height)
    {
        camera = global::Android.Hardware.Camera.Open((int)cameraType);
        textureView.LayoutParameters = new FrameLayout.LayoutParams(width, height);
        surfaceTexture = surface;

        camera.SetPreviewTexture(surface);
        PrepareAndStartCamera();
    }

    public bool OnSurfaceTextureDestroyed(SurfaceTexture surface)
    {
        camera.StopPreview();
        camera.Release();
        return true;
    }

    public void OnSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height)
    {
        PrepareAndStartCamera();
    }

    public void OnSurfaceTextureUpdated(SurfaceTexture surface)
    {

    }

    void PrepareAndStartCamera()
    {
        camera.StopPreview();

        var display = activity.WindowManager.DefaultDisplay;
        if (display.Rotation == SurfaceOrientation.Rotation0)
        {
            camera.SetDisplayOrientation(90);
        }

        if (display.Rotation == SurfaceOrientation.Rotation270)
        {
            camera.SetDisplayOrientation(180);
        }

        camera.StartPreview();
    }       
}

更新:Android 6.0 上的结果

Update: The result on Android 6.0

这篇关于使用捏来放大和缩小一些不需要的背景应该复制的颜色出现并且像素质量低 android 低于 9 版本 Xamarin android的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！