转换列表<Task<T>>> 到列表<T>

Question

我有这个变量应该投影并返回

AttachmentRequestModel

列表，如下所示：

 var mappedAttachments = recordAction
     .PPAttachments
     .Select(async x => new AttachmentRequestModel()
     {
         AttachmentId = 1,
         AttachmentContent = await GetReportAttachContentAsync(1),
         AttachmentName = "name",
         AttachmentType = 1
     })
     .ToList();

mappedAttachments

变量返回

List<Task<AttachmentRequestModel>>

我怎样才能将其更改为返回

List<AttachmentRequestModel>

？

编辑：我更改了代码，循环遍历列表中的每个任务并等待它，如下所示：

var anotherAttachList = new List<AttachmentRequestModel>();
foreach (var attachTask in mappedAttachments)
    anotherAttachList.Add(await attachTask);

我想知道是否有更好的方法来做到这一点。

Answer 1

尝试使用

Task.WhenAll

+

SelectMay()

,

的组合

 var mappedAttachments = (await Task.WhenAll(recordAction.PPAttachments
     .SelectMany(async x => new AttachmentRequestModel()
     {
         AttachmentId = 1,
         AttachmentContent = await GetReportAttachContentAsync(1),
         AttachmentName = "name",
         AttachmentType = 1
     })))
     .ToList();