imageView2 = (ImageView) findViewById(R.id.img2);        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);        //创建一个与bitmap一样大小的bitmap2        Bitmap bitmap2 = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());        Canvas canvas = new Canvas(bitmap2);        //主要以这个对象调用旋转方法        Matrix matrix = new Matrix();        //以图片中心作为旋转中心，旋转180°        matrix.setRotate(180, bitmap2.getWidth() / 2, bitmap2.getHeight() / 2);        Paint paint = new Paint();        //设置抗锯齿,防止过多的失真        paint.setAntiAlias(true);        canvas.drawBitmap(bitmap, matrix, paint);        //将旋转后的图片设置到界面上        imageView2.setImageBitmap(bitmap2);