android滑动一个路线后 人物图片按此路线移动的实现

一般思路是先做人物两点件移动，手滑动时记录划过的坐标点组成一个点的集合（可以设采样间隔不用记录每个点，间隔越小人物移动的越平滑），再循环取集合内相邻的两点做人物移动。

首先你得重写onTouchEvent是必须的,然后使用一个定义private ArrayList<PointF> pinfs = new ArrayList<PointF>();来存所以的点在onTouchEvent中。

 

switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
 pinfs.add(new PointF(event.getX(),event.getY()));
    break;
case MotionEvent.ACTION_MOVE:
   pinfs.add(new PointF(event.getX(),event.getY()));
    break;
case MotionEvent.ACTION_UP:
    invalidate();
    break;
}

然后在 @Override
protected void onDraw(Canvas canvas) {
    for (PointF point : pinfs) {
        这里绘制人物移动
    }

}

 

--------------------------------------------------------  以下是完整代码 ------------------------

 

    class CustomView1 extends View{
         
        private Paint paint;
        private ArrayList<PointF> graphics = new ArrayList<PointF>();
        private Paint  lPaint;
        private Path   mPath;
        private  int of = 0;
        private Boolean over =false;
        private float mX, mY;
        private static final float TOUCH_TOLERANCE = 4;
 
        public CustomView1(Context context) {
            super(context);
            paint = new Paint(Paint.ANTI_ALIAS_FLAG);
            paint.setColor(Color.RED);
            paint.setStrokeJoin(Paint.Join.ROUND);
            paint.setStrokeCap(Paint.Cap.ROUND);
            paint.setStrokeWidth(65);
            
            lPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            lPaint.setColor(Color.BLACK);
            lPaint.setStyle(Paint.Style.STROKE);//空心
            lPaint.setStrokeJoin(Paint.Join.ROUND);
            lPaint.setStrokeCap(Paint.Cap.ROUND);
            lPaint.setStrokeWidth(5);
            
            mPath = new Path();
            
        }
        
        @Override
        public boolean onTouchEvent(MotionEvent event) {
            float x = event.getX();
            float y = event.getY();
            switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                over = false;
                graphics.clear();
                of=0;
                graphics.add(new PointF(x, y));
                 touch_start(x, y);
                 invalidate();
                break;
            case MotionEvent.ACTION_MOVE:
                graphics.add(new PointF(x, y));
                touch_move(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                over = true;
                touch_up();
                invalidate();
                break;
        }
 
            return true;
        }
        
        private void touch_start(float x, float y) {
            mPath.reset();
            mPath.moveTo(x, y);
            mX = x;
            mY = y;
        }
        private void touch_move(float x, float y) {
            float dx = Math.abs(x - mX);
            float dy = Math.abs(y - mY);
            if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
                mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
                mX = x;
                mY = y;
            }
        }
        private void touch_up() {
            mPath.lineTo(mX, mY);
        }
 
        @Override
        protected void onDraw(Canvas canvas) {
        //    canvas.drawColor(Color.TRANSPARENT,Mode.CLEAR);
            canvas.drawColor(Color.WHITE);//清理
            canvas.drawPath(mPath, lPaint);
            if(over&&graphics.size()>0){
                canvas.drawPoint(graphics.get(of).x, graphics.get(of).y, paint);
                of+=1;
                if(of<graphics.size()){
                    if(of==graphics.size()-1){
                        mPath.reset();//移动完成后移除线条
                    }
                    invalidate();
                }
            }
        }
    }