The Benefits of SteamAPI UnregisterCallResult for Steamworks Developers
What You Need to Know About SteamAPI UnregisterCallResult
If you are a game developer using Steamworks, you may have encountered the function SteamAPI UnregisterCallResult. This function is used to cancel the registration of a callback object that was created with SteamAPI RegisterCallResult. In this article, we will explain what this function does, why it is important, and how to use it correctly.
{steamAPI Unregistercallresult}
What is SteamAPI UnregisterCallResult?
SteamAPI UnregisterCallResult is a function that takes two parameters: a pointer to a CCallResult object, and a SteamAPICall_t handle. The CCallResult object is a template class that allows you to create a callback object that will be called when an asynchronous API call completes. The SteamAPICall_t handle is a unique identifier for the API call that was made.
The purpose of SteamAPI UnregisterCallResult is to cancel the registration of the callback object for the given API call. This means that the callback object will not be called when the API call completes, and the CCallResult object can be safely deleted or reused.
Why is SteamAPI UnregisterCallResult important?
SteamAPI UnregisterCallResult is important because it prevents memory leaks and crashes that can occur if the callback object is deleted or reused before the API call completes. If you do not unregister the callback object, it will remain in memory and will be called when the API call completes, even if the CCallResult object has been deleted or reused for another API call. This can cause undefined behavior, such as accessing invalid memory, calling a wrong function, or corrupting data.
Therefore, you should always use SteamAPI UnregisterCallResult to cancel the registration of the callback object when you no longer need it, or when you want to reuse it for another API call.
How to use SteamAPI UnregisterCallResult correctly?
To use SteamAPI UnregisterCallResult correctly, you need to follow these steps:
Create a CCallResult object with the appropriate template parameter and callback function.
Make an asynchronous API call and store the returned SteamAPICall_t handle in the CCallResult object.
Use SteamAPI RegisterCallResult to register the callback object for the API call.
When you no longer need the callback object, or when you want to reuse it for another API call, use SteamAPI UnregisterCallResult to cancel the registration of the callback object for the previous API call.
Delete or reuse the CCallResult object as needed.
Here is an example of how to use SteamAPI UnregisterCallResult correctly:
// Create a CCallResult object with ISteamUserStats as the template parameter and OnUserStatsReceived as the callback function
CCallResult<CMyClass, UserStatsReceived_t> m_UserStatsReceived;
void CMyClass::OnUserStatsReceived( UserStatsReceived_t *pCallback )
// Do something with pCallback
// Make an asynchronous API call to request user stats and store the returned handle in the CCallResult object
SteamAPICall_t hSteamAPICall = SteamUserStats()->RequestCurrentStats();
m_UserStatsReceived.Set( hSteamAPICall, this, &CMyClass::OnUserStatsReceived );
// Register the callback object for the API call
SteamAPI_RegisterCallResult( &m_UserStatsReceived, hSteamAPICall );
// Later, when you no longer need the callback object, or when you want to reuse it for another API call, cancel the registration of the callback object for the previous API call
SteamAPI_UnregisterCallResult( &m_UserStatsReceived, hSteamAPICall );
// Delete or reuse the CCallResult object as needed
m_UserStatsReceived.Cancel();
Conclusion
SteamAPI UnregisterCallResult is a useful function that allows you to cancel the registration of a callback object that was created with SteamAPI RegisterCallResult. This prevents memory leaks and crashes that can occur if the callback object is deleted or reused before the API call completes. You should always use SteamAPI UnregisterCallResult when you no longer need the callback object, or when you want to reuse it for another API call.
How to Use SteamAPI UnregisterCallResult in Your Code
Now that you know what SteamAPI UnregisterCallResult is and why it is important, you may be wondering how to use it in your code. In this section, we will show you some examples of how to use SteamAPI UnregisterCallResult in different scenarios.
Example 1: Using SteamAPI UnregisterCallResult with CCallResult
One of the most common ways to use SteamAPI UnregisterCallResult is with CCallResult objects. CCallResult is a template class that allows you to create a callback object that will be called when an asynchronous API call completes. You can use CCallResult to handle API calls such as requesting user stats, downloading files, or uploading screenshots.
To use SteamAPI UnregisterCallResult with CCallResult, you need to follow these steps:
Create a CCallResult object with the appropriate template parameter and callback function.
Make an asynchronous API call and store the returned SteamAPICall_t handle in the CCallResult object.
Use SteamAPI RegisterCallResult to register the callback object for the API call.
When you no longer need the callback object, or when you want to reuse it for another API call, use SteamAPI UnregisterCallResult to cancel the registration of the callback object for the previous API call.
Delete or reuse the CCallResult object as needed.
Here is an example of how to use SteamAPI UnregisterCallResult with CCallResult:
// Create a CCallResult object with ISteamUserStats as the template parameter and OnUserStatsReceived as the callback function
CCallResult<CMyClass, UserStatsReceived_t> m_UserStatsReceived;
void CMyClass::OnUserStatsReceived( UserStatsReceived_t *pCallback )
// Do something with pCallback
// Make an asynchronous API call to request user stats and store the returned handle in the CCallResult object
SteamAPICall_t hSteamAPICall = SteamUserStats()->RequestCurrentStats();
m_UserStatsReceived.Set( hSteamAPICall, this, &CMyClass::OnUserStatsReceived );
// Register the callback object for the API call
SteamAPI_RegisterCallResult( &m_UserStatsReceived, hSteamAPICall );
// Later, when you no longer need the callback object, or when you want to reuse it for another API call, cancel the registration of the callback object for the previous API call
SteamAPI_UnregisterCallResult( &m_UserStatsReceived, hSteamAPICall );
// Delete or reuse the CCallResult object as needed
m_UserStatsReceived.Cancel();
Example 2: Using SteamAPI UnregisterCallResult with CCallback
Another way to use SteamAPI UnregisterCallResult is with CCallback objects. CCallback is a template class that allows you to create a callback object that will be called when a specific event occurs. You can use CCallback to handle events such as game overlay activation, friend requests, or achievements unlocked.
To use SteamAPI UnregisterCallResult with CCallback, you need to follow these steps:
Create a CCallback object with the appropriate template parameter and callback function.
Use SteamAPI RegisterCallback to register the callback object for the event.
When you no longer need the callback object, or when you want to reuse it for another event, use SteamAPI UnregisterCallback to cancel the registration of the callback object for the previous event.
Delete or reuse the CCallback object as needed.
Here is an example of how to use SteamAPI UnregisterCallResult with CCallback:
// Create a CCallback object with GameOverlayActivated_t as the template parameter and OnGameOverlayActivated as the callback function
CCallback<CMyClass, GameOverlayActivated_t> m_GameOverlayActivated;
void CMyClass::OnGameOverlayActivated( GameOverlayActivated_t *pCallback )
// Do something with pCallback
// Register the callback object for the event
SteamAPI_RegisterCallback( &m_GameOverlayActivated, k_iSteamUserCallbacks + 31 );
// Later, when you no longer need the callback object, or when you want to reuse it for another event, cancel the registration of the callback object for the previous event
SteamAPI_UnregisterCallback( &m_GameOverlayActivated );
// Delete or reuse the CCallback object as needed
m_GameOverlayActivated.Cancel();
Conclusion
In this article, we have explained what SteamAPI UnregisterCallResult is, why it is important, and how to use it correctly. We have also shown you some examples of how to use SteamAPI UnregisterCallResult with CCallResult and CCallback objects. We hope that this article has helped you understand how to use SteamAPI UnregisterCallResult in your code and avoid memory leaks and crashes that can occur if you do not unregister your callback objects properly.
Conclusion
SteamAPI UnregisterCallResult is a useful function that allows you to cancel the registration of a callback object that was created with SteamAPI RegisterCallResult. This prevents memory leaks and crashes that can occur if the callback object is deleted or reused before the API call completes. You should always use SteamAPI UnregisterCallResult when you no longer need the callback object, or when you want to reuse it for another API call.
In this article, we have explained what SteamAPI UnregisterCallResult is, why it is important, and how to use it correctly. We have also shown you some examples of how to use SteamAPI UnregisterCallResult with CCallResult and CCallback objects. We hope that this article has helped you understand how to use SteamAPI UnregisterCallResult in your code and avoid memory leaks and crashes that can occur if you do not unregister your callback objects properly. 4e3182286b