按下按钮时如何发送单个数据而不是在内部循环并在释放按钮时停止动作

Question

所以我正在使用 java 在我的移动应用程序中开发一个控制器，目前每当我触摸按钮时，它都会连续发送 3 个数据。当按钮释放时它应该只发送一个数据和另一个数据时

我可以设置在释放按钮时获取数据，但由于传递了很多数据，所以不准确

    upbtn.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            rosbridge.Publish("/set_velocity", nav_ctrl);
            if(event.getAction() == ACTION_DOWN) {
                nav_ctrl.linear.x = 0.6;
                nav_ctrl.angular.z = 0;
                return true;

            } else if (event.getAction() != MotionEvent.ACTION_UP) {
                    return false;
                }
                nav_ctrl.linear.x = 0;
                nav_ctrl.angular.z = 0;
            return false;
        }
    });

    downbtn.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            rosbridge.Publish("/set_velocity", nav_ctrl);
            if(event.getAction() == ACTION_MOVE) {
                    nav_ctrl.linear.x = -0.6;
                    nav_ctrl.angular.z = 0;
            } else if (event.getAction() == MotionEvent.ACTION_CANCEL) {
                nav_ctrl.linear.x = 0;
                nav_ctrl.angular.z = 0;
            }
            return false;
        }
    });


    leftbtn.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            rosbridge.Publish("/set_velocity", nav_ctrl);
            if(event.getAction() == ACTION_DOWN) {
                nav_ctrl.linear.x = 1.2;
                nav_ctrl.angular.z = 0;

                return true;

            } else if (event.getAction() == MotionEvent.ACTION_UP) {
                leftbtn.performClick();
                nav_ctrl.linear.x = 0;
                nav_ctrl.angular.z = 0;
            }
            return false;
        }
    });

    rightbtn.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            rosbridge.Publish("/set_velocity", nav_ctrl);
            if(event.getAction() == ACTION_DOWN) {
                nav_ctrl.linear.x = -1.2;
                nav_ctrl.angular.z = 0;
                return true;

            } else if (event.getAction() == MotionEvent.ACTION_UP) {
                nav_ctrl.linear.x = 0;
                nav_ctrl.angular.z = 0;
            }
            return false;
        }
    });

}

我希望只发送一行数据，例如："angular":{"x":0.0,"y":0.0,"z":0.0},"linear":{"x":- 0.6,"y":0.0,"z":0.0}},

输出相似，但传递了多个数据

Answer 1

问题在于您正在发布，无论事件类型如何。 您至少在touch 开始时发布一次，在touch 结束时至少发布一次，然后再次移动。没有检查，但如果你按住按钮，它也可能会一直开火。

将Publish 移动到ACTION_DOWN 块中

 public boolean onTouch(View v, MotionEvent event) {
            //rosbridge.Publish("/set_velocity", nav_ctrl); <--- This
            if(event.getAction() == ACTION_DOWN) {
                nav_ctrl.linear.x = 1.2;
                nav_ctrl.angular.z = 0;
                rosbridge.Publish("/set_velocity", nav_ctrl); <--- Goes here

                return true;

            } else if (event.getAction() == MotionEvent.ACTION_UP) {
                leftbtn.performClick();
                nav_ctrl.linear.x = 0;
                nav_ctrl.angular.z = 0;
            }
            return false;
        }