android - 在android中获取触摸形状

Question

我正在创建一个应用程序，我想在我的屏幕上绘制触摸事件的形状。有任何 ApI 来特别获取触摸事件的形状吗？

非常感谢任何示例或代码片段。

谢谢纳拉扬

Answer 1

此代码段应该实现您想要的：

public class TestActivity extends Activity {

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

    class DrawingView extends SurfaceView {

        private final SurfaceHolder surfaceHolder;
        private final Path path = new Path();
        private final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

        public DrawingView(Context context) {
            super(context);
            surfaceHolder = getHolder();
            paint.setStyle(Paint.Style.STROKE);
            paint.setStrokeWidth(3);
            paint.setColor(Color.WHITE);
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            switch(event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                path.moveTo(event.getX(), event.getY());
                break;
            case MotionEvent.ACTION_MOVE:
                if (surfaceHolder.getSurface().isValid()) {
                    Canvas canvas = surfaceHolder.lockCanvas();
                    path.lineTo(event.getX(), event.getY());
                    canvas.drawPath(path, paint);
                    surfaceHolder.unlockCanvasAndPost(canvas);
                }
                break;
            }
            return true;
        }

    }

}