Android UI SurfaceView的使用-绘制单个图型或多个图形

新建MyView类继承自SurfaceView:

public class MyView extends SurfaceView implements SurfaceHolder.Callback {

	private Paint paint;
	public MyView(Context context) {
		super(context);
		paint=new Paint();
		paint.setColor(Color.RED);
		getHolder().addCallback(this);
	}
	public void draw(){
		//绘制画布前锁定画布
		Canvas canvas=getHolder().lockCanvas();
		canvas.drawColor(Color.WHITE);
		//从画布的50x50开始绘制，绘制到100x100,绘制面积50x50
		canvas.drawRect(50, 50, 100, 100, paint);
		//将第一条线顺时针旋转90度
		canvas.save(); //将画布处可编辑状态
		canvas.rotate(90,getWidth()/2,getHeight()/2); //按中心点进行旋转
		canvas.drawLine(0, getHeight()/2, getWidth(), getHeight(), paint);
		canvas.restore();// 将画布复原
		canvas.drawLine(0, getHeight()/2+100, getWidth(), getHeight()+100, paint);

		//绘制画布结束后解锁画布
		getHolder().unlockCanvasAndPost(canvas);
	}
	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		draw();
	}

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
	}

MainActivity:

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyView(this));
    }

效果：

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