vue 强制刷新子组件

原因：因为父组件有缓存等因素，子组件创建后没有释放，传入参数无效，使用v-if的特性（销毁和重建）可以强制刷新子组件

    <el-drawer
      ref="detailTable"
      :title="detailTitle"
      :append-to-body="true"
      :visible.sync="dialogDetailFormVisible"
      direction="ltr"
      :wrapper-closable="false"
      size="90%"
    >
      <div class="el-drawer__body">
        <el-row :gutter="10">
          <el-col :span="22" :offset="1">
            <ProjectMileStone v-if="forceRefresh" :project-id="projectId" />
          </el-col>
        </el-row>
      </div>
    </el-drawer>

toView(row) {
      this.forceRefresh = false
      this.projectId = row.projectId
      this.detailTitle = row.projectName
      // 强制刷新子组件
      this.$nextTick(() => {
        this.forceRefresh = true
        this.dialogDetailFormVisible = true
      })
    }