watch，computed和methods的关系

watch和computed各自处理的数据关系场景不同

1.watch擅长处理的场景：一个数据影响多个数据

2.computed擅长处理的场景：一个数据受多个数据影响

   watch: {
            option1: {
                handler(newVal, oldVal) {
                    if (this.tgshowdataList.length > 0) {
                        var myChart1 = echarts.init(document.getElementById('indexc2'));
                        if (myChart1) {
                            if (newVal) {
                                myChart1.setOption(newVal);
                            } else {
                                myChart1.setOption(oldVal);
                            }
                        }
                    }
                },
                immediate: true,
                deep: true
            }
}

  computed: {
            evidenceuploadList() {
                return this.$refs.evidenceupload ? this.$refs.evidenceupload.fileList : [];
            },
            evidenceUploadUrl() {
                return this.base.obj.onlinedomainUrl + '/legalcase/evidence/uploadFile';
            },
        }