new Client

{

    ClientId = "xamarin",

    ClientSecrets = { new Secret("secret".Sha256()) },

    AccessTokenLifetime = ,//设置AccessToken过期时间

    AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,

    RefreshTokenExpiration = TokenExpiration.Absolute,

    AbsoluteRefreshTokenLifetime = ,

    AllowOfflineAccess = true,//如果要获取refresh_tokens ,必须把AllowOfflineAccess设置为true

    AllowedScopes = new List<string>

    {

        "api",

        StandardScopes.OfflineAccess, //如果要获取refresh_tokens ,必须在scopes中加上OfflineAccess

        StandardScopes.OpenId,//如果要获取id_token,必须在scopes中加上OpenId和Profile，id_token需要通过refresh_tokens获取AccessToken的时候才能拿到（还未找到原因）

        StandardScopes.Profile//如果要获取id_token,必须在scopes中加上OpenId和Profile

    }

}

public class ResourceOwnerPasswordValidator : IResourceOwnerPasswordValidator

{

    public Task ValidateAsync(ResourceOwnerPasswordValidationContext context)

    {

        //根据context.UserName和context.Password与数据库的数据做校验，判断是否合法

        if (context.UserName == "test" && context.Password == "test")

        {

            context.Result = new GrantValidationResult(

                subject: context.UserName,

                authenticationMethod: OidcConstants.AuthenticationMethods.Password);

        }

        else

        {

            //验证失败

            context.Result = new GrantValidationResult(

                TokenRequestErrors.InvalidGrant,

                "invalid custom credential"

                );

        }

        return Task.FromResult();

    }

}

services.AddIdentityServer()

    .AddDeveloperSigningCredential()

    .AddInMemoryApiResources(Config.GetApis())

    .AddInMemoryIdentityResources(Config.GetIdentityResources())

    .AddInMemoryClients(Config.GetClients())

    .AddProfileService<ProfileService>()

    .AddResourceOwnerValidator<ResourceOwnerPasswordValidatorService>();//注入自定义用户登录验证