vue中echarts詞云點(diǎn)擊報(bào)錯(cuò)Cannot read property 'click' of null

        myChart.on('click', function (params) {
          //alert((params.name));
          console.log(params.name)
        });
    

沒(méi)有問(wèn)題，但是引用參數(shù)的時(shí)候就不行了

        var _this = this
        myChart.on('click', function (params) {
          //alert((params.name));
          _this.pass()
        });
    

求大佬?。。?/p>