uni-app canvas 触发不了touch事件

uni-app canvas 触发不了touch事件 微信开发者工具中能正常触发，但是真机扫码触发不了。直接使用微信原生代码能正常触发

<template>  
  <view class="page">  
    <canvas id="cs" type="2d" @touchstart="onTouchStart"></canvas>  
  </view>  
</template>  

<script lang="ts">  
import { defineComponent } from 'vue'  

export default defineComponent({  
  methods: {  
    onTouchStart() {  
      uni.showToast({ title: 'touch start', icon: 'none' });  
    },  
  }  
});  
</script>