获得图像

1.使用BitmapDrawable获取位图
Resources res = context.getResources();
            // cache handles to our key sprites & other drawables
            mLanderImage = context.getResources().getDrawable(
                    R.drawable.lander_plain);
2. 使用BitmapFactory获取位图
mBackgroundImage = BitmapFactory.decodeResource(res,
                    R.drawable.earthrise);
3.使用Canvas类显示位图
public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new Panel(this));
    }
   
    class Panel extends View{      
        public Panel(Context context) { 
            super(context);
        }     
        public void onDraw(Canvas canvas){ 
            Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.pic180); 
            canvas.drawColor(Color.BLACK); 
            canvas.drawBitmap(bmp, 10, 10, null); 
        } 
    }
}
4.位图缩放
  Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.pic180); 
            Matrix matrix=new Matrix();
            matrix.postScale(0.2f, 0.2f);
            Bitmap dstbmp=Bitmap.createBitmap(bmp,0,0,bmp.getWidth(),
            bmp.getHeight(),matrix,true);
            canvas.drawColor(Color.BLACK); 
            canvas.drawBitmap(dstbmp, 10, 10, null); 
5.位图旋转
  Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.pic180); 
            Matrix matrix=new Matrix();
            matrix.postScale(0.8f, 0.8f);
            matrix.postRotate(45);
            Bitmap dstbmp=Bitmap.createBitmap(bmp,0,0,bmp.getWidth(),
            bmp.getHeight(),matrix,true);
            canvas.drawColor(Color.BLACK);
            canvas.drawBitmap(dstbmp, 10, 10, null);