Converting Android View to Bitmap

Converting Android View to Bitmap
The parameter Canvas of the onDraw method in the View class is the background of View painting. to convert a View to a Bitmap, the painting operation on the Canvas is actually drawn to the Bitmap. The process of converting a View to a Bitmap is also called a screenshot. The methods in the View class involved in converting View to Bitmap include:

   protected void onDraw(Canvas canvas)   public void buildDrawingCache()   public void destroyDrawingCache()   public Bitmap getDrawingCache()   public void setDrawingCacheEnabled(boolean enabled)

 

The following are examples of common View screenshots: 1. View-to-Bitmap

public final Bitmap screenShot(View view) {        if (null == view) {            throw new IllegalArgumentException("parameter can't be null.");        }        view.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);        view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());        view.setDrawingCacheEnabled(true);        view.buildDrawingCache();        Bitmap bitmap = view.getDrawingCache();        return bitmap;    }  

 

2. The Activity is converted to Bitmap without the status bar.

public final Bitmap screenShot(Activity activity) {        if (null == activity) {            throw new IllegalArgumentException("parameter can't be null.");        }        View view = activity.getWindow().getDecorView();        view.setDrawingCacheEnabled(true);        view.buildDrawingCache();        Bitmap b1 = view.getDrawingCache();        Rect frame = new Rect();        view.getWindowVisibleDisplayFrame(frame);        int statusBarHeight = frame.top;        Point point = new Point();        activity.getWindowManager().getDefaultDisplay().getSize(point);        int width = point.x;        int height = point.y;        Bitmap b2 = Bitmap.createBitmap(b1, 0, statusBarHeight, width, height - statusBarHeight);        view.destroyDrawingCache();        return b2;    }

 

3. ScrollView to long Bitmap (similar to the screenshot of a hammer tab)

 public final Bitmap screenShot(ScrollView scrollView) {        if (null == scrollView) {            throw new IllegalArgumentException("parameter can't be null.");        }        int height = 0;        Bitmap bitmap;        for (int i = 0, s = scrollView.getChildCount(); i < s; i++) {            height += scrollView.getChildAt(i).getHeight();            scrollView.getChildAt(i).setBackgroundResource(android.R.drawable.screen_background_light);        }        bitmap = Bitmap.createBitmap(scrollView.getWidth(), height, Bitmap.Config.ARGB_8888);        final Canvas canvas = new Canvas(bitmap);        scrollView.draw(canvas);        return bitmap;    }