【Android】38.使用SurfaceView绘制图形

38.使用SurfaceView绘制图形

1.下载素材。

本节素材源码，请在公众号回复" AS12192 "。

2.SurfaceView绘制单个图形。

1.新建MyView。

public class MyView extends SurfaceView implements Callback {

	private Paint paint = null;

	public MyView(Context context) {
		super(context);
		paint = new Paint();
		paint.setColor(Color.BLUE);
		getHolder().addCallback(this);
	}

	public void draw() {
		Canvas canvas = getHolder().lockCanvas();
		canvas.drawColor(Color.WHITE);
		canvas.drawRect(0, 0, 800, 300, paint);
		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) { }

}

2.修改MainActivity。

public class MainActivity extends AppCompatActivity{

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

}

3.效果图。

3.SurfaceView绘制多个图形。

1.新建MyView。

public class MyView extends SurfaceView implements Callback {

	private Paint paint = null;

	public MyView(Context context) {
		super(context);
		paint = new Paint();
		paint.setColor(Color.BLUE);
		getHolder().addCallback(this);
	}

	public void draw() {
		Canvas canvas = getHolder().lockCanvas();
		canvas.drawColor(Color.WHITE);
		canvas.save();
		canvas.rotate(90, getWidth()/2,getHeight()/2);
		canvas.drawLine(0, getHeight() / 2, getWidth(), getHeight(), paint);
		canvas.restore();
		canvas.drawLine(0, getHeight() / 2 + 100, getWidth(), getHeight() + 100, paint);
		getHolder().unlockCanvasAndPost(canvas);
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
		draw();
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) { }

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) { }

}

2.修改MainActivity。

public class MainActivity extends AppCompatActivity{

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

}

3.效果图。

4.SurfaceView绘制组合图形。

1.新建Contanier。

public class Contanier {

	private List<Contanier> children = null;
	private float x = 0, y = 0;

	public Contanier() {
		children = new ArrayList<Contanier>();
	}

	public void draw(Canvas canvas) {
		canvas.save();
		canvas.translate(getX(), getY());
		childrenView(canvas);
		for (Contanier c : children) {
			c.draw(canvas);
		}
		canvas.restore();
	}

	public void childrenView(Canvas canvas) {
	}

	public void addChildrenView(Contanier child) {
		children.add(child);
	}

	public void removeChildrenView(Contanier child) {
		children.remove(child);
	}

	public float getX() {
		return x;
	}

	public void setX(float x) {
		this.x = x;
	}

	public float getY() {
		return y;
	}

	public void setY(float y) {
		this.y = y;
	}

}

2.新建Circle。

public class Circle extends Contanier {

	private Paint paint = null;

	public Circle() {
		paint = new Paint();
		paint.setColor(Color.YELLOW);
	}

	@Override
	public void childrenView(Canvas canvas) {
		super.childrenView(canvas);
		canvas.drawCircle(500, 500, 500, paint);
	}
}

3.新建Rect。

public class Rect extends Contanier {

	private Paint paint = null;
	private GameView view = null;
	public Rect() {
		paint = new Paint();
		paint.setColor(Color.BLACK);
	}

	@Override
	public void childrenView(Canvas canvas) {
		super.childrenView(canvas);
		canvas.drawRect(0, 0, 1000, 1000, paint);
		this.setY(this.getY() + 5);
		this.setX(this.getX() + 5);
	}
}

4.新建GameView。

public class GameView extends SurfaceView implements Callback {

	private Contanier contanier;
	private Rect rect;
	private Circle circle;

	public GameView(Context context) {
		super(context);
		contanier = new Contanier();
		rect = new Rect();
		circle = new Circle();
		rect.addChildrenView(circle);
		contanier.addChildrenView(rect);
		getHolder().addCallback(this);
	}

	public void draw() {
		Canvas canvas = getHolder().lockCanvas();
		canvas.drawColor(Color.WHITE);
		contanier.draw(canvas);
		getHolder().unlockCanvasAndPost(canvas);
	}

	private Timer timer = null;
	private TimerTask task = null;

	public void startTimer() {
		timer = new Timer();
		task = new TimerTask() {

			@Override
			public void run() {
				draw();
			}
		};
		timer.schedule(task, 100, 100);
	}

	public void stopTimer() {
		if (timer != null) {
			timer.cancel();
			timer = null;
		}
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { }

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

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
		stopTimer();
	}

}

5.修改MainActivity。

public class MainActivity extends Activity {

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

}

6.效果图。