android bit地图对角线旋转和画图

Bitmap对角线进行旋转（右上左下）：

public Bitmap convert(Bitmap mBitmap, int width, int height) {		int w = mBitmap.getWidth();		int h = mBitmap.getHeight();		Bitmap newBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);		Canvas mCanvas = new Canvas(newBitmap);		Matrix matrix = new Matrix();		matrix.postScale(1, -1);		matrix.postRotate(-90);		Bitmap mBitmap2 = Bitmap.createBitmap(mBitmap, 0, 0, w, h, matrix, true);		mCanvas.drawBitmap(mBitmap2, new Rect(0, 0, mBitmap2.getWidth(), mBitmap2.getHeight()), new Rect(0, 0, width, height), null);		return newBitmap;	}

? 在Bitmap上画图：

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public Bitmap drawRect(Bitmap bitmap) {		Paint paint = new Paint();		paint.setColor(Color.RED);		paint.setStyle(Style.STROKE);		Bitmap newBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);		Canvas mCanvas = new Canvas(newBitmap);		mCanvas.drawBitmap(bitmap, 0, 0, null);		mCanvas.drawRect(0, 0, 20, 20, paint);		mCanvas.save(Canvas.ALL_SAVE_FLAG);		mCanvas.restore();		return newBitmap;	}

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