Android图片拉伸和缩放

    private void initialize() {  
        DisplayMetrics dm = getResources().getDisplayMetrics();  
        mScreenWidth = dm.widthPixels;//屏幕宽  
        mScreenHeight = dm.heightPixels;//屏幕高  
        //mScreenWidth =100;
        //mScreenHeight =100;//缩放
        //mScreenWidth =500;
        //mScreenHeight =500;//放大
        Bitmap bmp = ((BitmapDrawable)getResources().getDrawable(R.drawable.show)).getBitmap();//源图片 
        Bitmap mBitmap = Bitmap.createScaledBitmap(bmp, mScreenWidth, mScreenHeight, true); //按指定大小转换
    }