react 按下鼠标移动监听不到onMouseMove事件，松开时也监听不到onMouseUp

Question

<img alt="" src={Url}

  onMouseDown={handleMouseDown}

  onMouseMove={handleMouseMove}

  onMouseUp={handleMouseUp}

/>

事件

  let flag = false

  const handleMouseDown = () => {

    flag = true

    console.log('down')

  }

  const handleMouseMove = () => {

    if (flag) {

      console.log('move')

    }

  }

  const handleMouseUp = () => {

    console.log('up')

    flag = false

  }

想要实现从图片中选取一个区域，当按下鼠标时可以监听到，按着移动和松开都监听不到。在原地按下松开可以监听到。

请大家帮忙看看