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();
}
}
}
}