c# - 等待调用后异步的 HttpContext.Current null

Question

HttpContext.Current 在等待调用后异步为 null。

这是我的代码:

if (!string.IsNullOrEmpty(securityGroupName))
{
    // To remove the domain name from the security group name.
    string securityGroupDisplayName = securityGroupName.Split('\\')[1];
    string serviceSecurityGroupId = await this.graphApiClient.GetGroupIdAsync(securityGroupDisplayName).ConfigureAwait(false);

    if (!string.IsNullOrEmpty(serviceSecurityGroupId))
    {
        Task securityGroupRoleAddTask = this.CheckMembershipAndAddRole(serviceSecurityGroupId, userId, securityGroupName);
        Task flightAdminRoleAddTask = this.CheckMembershipAndAddRole(FlightAdminSecurityGroupId, userId, FlightAdminRoleName);
        Task.WaitAll(securityGroupRoleAddTask, flightAdminRoleAddTask);
    }
    else
    {
        LoggingUtilities.Logger.TraceInformation("Azure AD id does not exist for the security group: {0}.", securityGroupName);
        await this.CheckMembershipAndAddRole(FlightAdminSecurityGroupId, userId, FlightAdminRoleName).ConfigureAwait(false);
    }
}
else
{
    LoggingUtilities.Logger.TraceInformation("Security group name is not valid, checking for flight admin role for the user: {0}.", userAlias);
    await this.CheckMembershipAndAddRole(FlightAdminSecurityGroupId, userId, FlightAdminRoleName).ConfigureAwait(false);
}

// Add the flight privileged users role to be able to verify the user is authorized for the role.
string flightPrivilegedUsersRoleName = RoleRepository.Instance.GetByName(Constants.FlightPrivilegedUsersRoleKey).Name;
if (!this.roles.Contains(flightPrivilegedUsersRoleName, StringComparer.OrdinalIgnoreCase))
{
    LoggingUtilities.Logger.TraceInformation("Adding flight privileged users to roles list for the user: {0}.", userAlias);
    this.roles.Add(flightPrivilegedUsersRoleName);
}

if (userAlias != null)
{
    LoggingUtilities.Logger.TraceInformation("Check security group memberships and assign roles for the user: {0}.", userAlias);
    var newPrincipal = new GenericPrincipal(new GenericIdentity(userAlias), this.roles.ToArray());
    Thread.CurrentPrincipal = newPrincipal;
    HttpContext.Current.User = newPrincipal;
}

关于 web.config 条目中以下条目的建议没有帮助:

<system.web>
    <compilation debug="false" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" enableVersionHeader="false" requestPathInvalidCharacters="&lt;,&gt;,%,&amp;,\,?" />
</system.web>
<appSettings>
    <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true" />
</appSettings>

如有任何关于如何解决此问题的建议，我们将不胜感激。

Answer 1

删除您的 .ConfigureAwait(false) 调用。他们是给你带来麻烦的原因。当您调用 .ConfigureAwait(false) 时，它会告诉 C# 您不关心使用哪个线程来完成异步调用。您最终进入另一个没有 HttpContext.Current 上下文的线程，因为它是一个线程池线程，而不是 ASP.NET 线程。