Step 3: Login and Logout

Feature Description

After initializing the IM SDK, you need to call the SDK login API to authenticate your account to get the permissions to use message, conversation, and other features.
Caution:
Only the conversation acquisition API can be called immediately after you call the login API, and other APIs can be called only after you have successfully logged in to the SDK. Therefore, make sure that you have logged in successfully before using other features; otherwise, such features may become abnormal or unavailable.

Login

You don't need to sign up on your first login, as you will automatically sign up if the login is successful. You can call the Login API (Details) to log in.
Key parameters of the Login API are as follows:
Parameter
Description
Remarks
user_id
Unique user ID
It can contain up to 32 bytes of letters (a-z and A-Z), digits (0-9), underscores (_), and hyphens (-).
user_sig
Login ticket
It is calculated by your business server to ensure security. For more information, see Generating UserSig.
callback
Async callback
You can call the Login API in the following scenarios:
You use the features of the IM SDK for the first time after your application is started.
Your ticket expires on login: The callback of the Login API returns the ERR_USER_SIG_EXPIRED (6206) or ERR_SVR_ACCOUNT_USERSIG_EXPIRED (70001) error code. In this case, you need to generate a new user_sig to log in again.
Your ticket expires when the user is online: You might receive the UserSigExpiredCallback callback (Details) when users are online. In this case, you need to generate a new user_sig to log in again.
A user is kicked offline: When a user is kicked offline, the IM SDK will notify you through the KickedOfflineCallback callback (Details). In this case, you can prompt the user and call Login to log in again.
You don't need to call the Login API in the following scenarios:
After the user's network is disconnected and then reconnected, you don't need to call the Login function, as the IM SDK will automatically go online.
The login process is running.
Caution:
1. After you call the IM SDK API and log in successfully, DAU calculation will start; therefore, call the login API as needed to avoid a high DAU. 2. You cannot log in to multiple IM SDK accounts of the same application at the same time; otherwise, only the last logged in account will be online.
Sample code:
public static void Login() {
if (userid == "" || user_sig == "")
{
return;
}
TIMResult res = TencentIMSDK.Login(userid, user_sig, (int code, string desc, string json_param, string user_data)=>{
// Process the login callback logic
});

Getting the UserID

After logging in successfully, call GetLoginUserID (Details) to get the UserID. If the login fails, the UserID will be empty.
Sample code:
public static void GetLoginUserID()
{
StringBuilder userId = new StringBuilder(128);

TIMResult res = TencentIMSDK.GetLoginUserID(userId);

Debug.Log(userId.ToString());
}

Getting the login status

Call GetLoginStatus (Details) to get the login status. If a user is logged in or logging in, don't call the login API frequently. The IM SDK supports the following login statuses:
Login Status
Description
kTIMLoginStatus_Logined
Logged in
kTIMLoginStatus_Logining
Logging in
kTIMLoginStatus_Logouting
Logging out
kTIMLoginStatus_UnLogined
Not logged in
Sample code:
public static void GetLoginStatus()
{
TIMLoginStatus res = TencentIMSDK.GetLoginStatus();
}

Multi-Client Login and Mutual Kickout

You can configure multi-client login policies for the IM SDK in the Tencent Cloud console. There are multiple multi-client login policies, such as A user can be concurrently online on a mobile or desktop platform and the web platform or A user can be concurrently online on all platforms. For more information on the configuration, see Feature Configuration.
You can configure the Max Login Instances per User per Platform for the IM SDK in the Tencent Cloud console, that is, the maximum number of instances on the same platform that can be concurrently online. This feature is available only for the Ultimate edition. A user can be concurrently online on up to ten clients on the web platform or on up to three clients on the Android, iPhone, iPad, Windows, or macOS platform (the maximum number of clients that can be concurrently online on Flutter is subject to the actual compilation result). For more information on the configuration, see Feature Configuration.
When you call the Login API (Details) to log in, if the limit specified by the multi-client login policy for your account is exceeded, a newly logged in instance will kick out an earlier one. The one kicked out will receive KickedOfflineCallback (Details).

Logout

Generally, if your application's lifecycle is the same as the IM SDK's lifecycle, there is no need to log out before exiting the application. In special cases, for example, if you use the IM SDK only after entering a specific UI and no longer use it after exiting the UI, you can call the Logout API (Details) to log out of the SDK, after which you will no longer receive new messages. Note that in this case, you also need to call Uninit (Details) after the logout to uninitialize the SDK.
Sample code:
public static void Logout()
{
TIMResult res = TencentIMSDK.Logout((int code, string desc, string json_param, string user_data)=>{
// Process the logout callback logic
});
}

Account Switch

Call Login (Details) to switch between accounts in the application.
For example, to switch the logged-in user from Alice to Bob, just call Login bob. You don't need to explicitly call logout alice, as this operation will be handled automatically inside the IM SDK.


FAQs



1. What should I do if error code 6013 is returned along with the description "not initialized" when I call the login or another API?