Android不规则形状点击检测

最新推荐文章于 2021-05-26 07:55:28 发布

原创最新推荐文章于 2021-05-26 07:55:28 发布 · 654 阅读

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本文介绍了一个自定义的Android视图TouchRegionView，该视图使用Region和Path来定义一个圆形触摸区域。当用户触摸屏幕上的这个圆形区域时，会显示提示信息。

public class TouchRegionView extends View {

    Paint paint = new Paint();
    //主要是Region ,region存储了圆的Path
    Region circleRegion;//圆的Region
    Path circlePath;//圆的path

    public TouchRegionView(Context context) {
        super(context);
    }

    public TouchRegionView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public TouchRegionView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public TouchRegionView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        circlePath = new Path();
        circlePath.addCircle(400, 600, 300, Path.Direction.CW);
        Region region = new Region(0, 0, getMeasuredWidth(), getMeasuredHeight());
        circleRegion = new Region();
        //把圆的path 添加到圆的Region中
        circleRegion.setPath(circlePath, region);
        paint.setColor(Color.GREEN);
        canvas.drawPath(circlePath, paint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            boolean contains = circleRegion.contains((int) event.getX(), (int) event.getY());
            if (contains) {
                Toast.makeText(getContext(), "点击了圆", Toast.LENGTH_LONG).show();
            }
        }
        return super.onTouchEvent(event);
    }
}

只有点击圆才会Toast