这是由于Android辅助服务的限制，只能处理单点触摸而非多点触摸引起的问题。为了解决这个问题，应该使用Android触摸事件处理程序来处理多点触摸事件。下面是一个包含示例代码的

1.创建一个自定义的View类，用于处理多点触摸事件：

public class MultiTouchView extends View {
   private Paint paint;
   private int[] colors = {Color.RED, Color.GREEN, Color.BLUE};
   private List points = new ArrayList<>();

   public MultiTouchView(Context context, AttributeSet attrs) {
       super(context, attrs);
       paint = new Paint(Paint.ANTI_ALIAS_FLAG);
       paint.setStyle(Paint.Style.FILL);
   }
   @Override
   public boolean onTouchEvent(MotionEvent event) {
       switch (event.getActionMasked()) {
           case MotionEvent.ACTION_DOWN:
           case MotionEvent.ACTION_POINTER_DOWN:
               int index = event.getActionIndex();
               PointF point = new PointF(event.getX(index), event.getY(index));
               points.add(point);
               break;
           case MotionEvent.ACTION_MOVE:
               for (int i = 0; i < event.getPointerCount(); i++) {
                   index = i;
                   point = points.get(i);
                   point.x = event.getX(i);
                   point.y = event.getY(i);
               }
               break;
           case MotionEvent.ACTION_UP:
           case MotionEvent.ACTION_POINTER_UP:
           case MotionEvent.ACTION_CANCEL:
               index = event.getActionIndex();
               points.remove(index);
               break;
       }
       invalidate();
       return true;
   }

   @Override
   protected void onDraw(Canvas canvas) {
       for (int i = 0; i < points.size(); i++) {
           paint.setColor(colors[i % colors.length]);
           canvas.drawCircle(points.get(i).x, points.get(i).y, 50, paint);
       }
   }
}

2.在布局文件中引用自定义的View类，并使用属性“android:onClick”将其与一个按钮关联起来：