鸿蒙arkts利用Promise.all()解决获取列表数据异步问题

原来代码

this.jobs.forEach((job) => {
        let jobGroup: JobGroup = {
          title: 'Job--' + job.jobName,
          tasks: []
        };
        /*todo 因为是异步请求导致顺序有问题*/
        taskApi.getCoordinatesByJobId(job.id).then((data) => {
          this.tasks = data.data;
          console.info("hCom.ets---Tasks for jobid " + job.id + ": " + JSON.stringify(this.tasks));
          // jobGroup.tasks= [];// 初始化 jobGroup的tasks 为一个空数组
          this.tasks.forEach((task) => {
            //创建taskShow对象完成
            let taskShow: TaskShow = {
              key: task.taskId,
              name: 'Task' + task.taskId,
              icon:$r('app.media.taskIcon')
            };
            jobGroup.tasks.push(taskShow);
          });
          this.jobGroups.push(jobGroup);
        }).catch((error) => {
          console.log('Error fetching tasks for jobid ' + job.id + ': ', error);
        });
});

套一层Promise.all()

 let promises = this.jobs.map(job => {
          return taskApi.getCoordinatesByJobId(job.id).then(data => {
            this.tasks = data.data;
            console.info("Tasks for jobid " + job.id + ": " + JSON.stringify(this.tasks));

            let jobGroup: JobGroup = {
              title: 'Job--' + job.jobName,
              tasks: []
            };

            this.tasks.forEach(task => {
              let taskShow: TaskShow = {
                key: task.taskId,
                name: 'Task' + task.taskId,
                icon: $r('app.media.taskIcon')
              };
              jobGroup.tasks.push(taskShow);
            });

            return jobGroup;
          }).catch(error => {
            console.log('Error fetching tasks for jobid ' + job.id + ': ', error);
            return null;
          });
        });
Promise.all(promises).then(jobGroups => {
          // jobGroups 数组现在包含了所有按顺序处理好的 jobGroup 对象
          this.jobGroups = jobGroups.filter(group => group !== null); // 过滤掉可能的错误结果(如果需要)
        });

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转载自blog.csdn.net/m0_63229791/article/details/140352250