英文:
'IAsyncEnumerable<T>' does not contain a definition for 'GetAwaiter' and no accessible extension method 'GetAwaiter'
问题
如何解决这个问题？
服务类：
public async IAsyncEnumerable<UserDTO> GetAllUsers()
{
var allUsers = _userManager.Users.AsAsyncEnumerable();
await foreach (IdentityUser user in allUsers)
{
yield return new UserDTO
{
Id = user.Id,
UserName = user.UserName,
Email = user.Email,
Password = null
};
}
}
接口定义：
public IAsyncEnumerable<UserDTO> GetAllUsers();
控制器：
private readonly IUserService _userService;
public async IAsyncEnumerable<UserDTO> GetAllUsers()
{
yield return await _userService.GetAllUsers();
}
控制器中的完整错误信息：await _userService.GetAllUsers()
错误信息：CS1061 'IAsyncEnumerable
英文:
How to solve this issue ?
Service class:
public async IAsyncEnumerable<UserDTO> GetAllUsers()
{
var allUsers= _userManager.Users.AsAsyncEnumerable();
await foreach (IdentityUser user in allUsers)
{
yield return new UserDTO
{
Id = user.Id,
UserName = user.UserName,
Email = user.Email,
Password = null
};
}
}
Interface definition
public IAsyncEnumerable<UserDTO> GetAllUsers();
Controller
private readonly IUserService _userService;
public async IAsyncEnumerable<UserDTO> GetAllUsers()
{
yield return await _userService.GetAllUsers();
}
Full error in controller: await _userService.GetAllUsers()
> Error CS1061 'IAsyncEnumerable<UserDTO>' does not contain a definition for 'GetAwaiter' and no accessible extension method 'GetAwaiter' accepting a first argument of type 'IAsyncEnumerable<UserDTO>' could be found (are you missing a using directive or an assembly reference?)
答案1
得分: 1
你不能await一个IAsyncEnumerable<T>。await返回一个单一的实例，而IAsyncEnumerable<T>是一个流。
你可以像GetAllUsers一样await foreach一个IAsyncEnumerable<T>，然后每次yield return一个。但在这种情况下，你已经有了IAsyncEnumerable<T>实例，所以直接返回它更有意义：
public IAsyncEnumerable<UserDTO> GetAllUsers()
{
return _userService.GetAllUsers();
}
英文:
You can't await an IAsyncEnumerable<T>. await returns a single instance, while IAsyncEnumerable<T> is a stream.
You can await foreach an IAsyncEnumerable<T>, just like GetAllUsers does, and yield return each one. But in this case, you already have the IAsyncEnumerable<T> instance, so it makes more sense to just return it directly:
public IAsyncEnumerable<UserDTO> GetAllUsers()
{
return _userService.GetAllUsers();
}
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