How can I reference a Widget Class in C++

Development Programming & Scripting C++
1

I’m following one of Epic’s C++ tutorials on using UMG: https://docs.unrealengine.com/en-us/Programming/Tutorials/UMG

On the third page of the tutorial, we create a Widget Blueprint in the editor with a parent class of UMG.UserWidget. We then make a button and hook up blueprint scripting for the On Clicked event like so:

https://forums.unrealengine.com/filedata/fetch?filedataid=165252&type=thumb

The function Change Menu Widget is created in C++ as part of the tutorial and is defined as follows:

// Pasted from the header
/** The widget instance that we are using as our menu. / UPROPERTY() UUserWidget CurrentWidget; // End paste from header
void AHowTo_UMGGameMode::ChangeMenuWidget(TSubclassOf<UUserWidget> NewWidgetClass) { if (CurrentWidget != nullptr) { CurrentWidget->RemoveFromViewport(); CurrentWidget = nullptr; } if (NewWidgetClass != nullptr) { CurrentWidget = CreateWidget<UUserWidget>(GetWorld(), NewWidgetClass); if (CurrentWidget != nullptr) { CurrentWidget->AddToViewport(); } } }

What I would like to do is hook up the On Clicked blueprint scripting event to a single C++ function that does what all of the blueprint scripting accomplishes. If I’m not mistaken, the issue I’m having is finding out how to reference a Blueprint Widget through C++. Is this possible? And if not, is it possible to handle all functionality from a blueprint event by hooking it up to a single C++ fucntion?

Thanks!

2

Did you find a solution.

I have the same problem.
If you find a solution please share how you did it.

Thank you very much.

3

In Epic’s tutorial the UMG is using Game Mode’s reference to use its function.

What you could do is create a C++ class that inherit from UserWidget:

UW_1
UW_11173×707 33.8 KB

In this class you create a public UFUNCTION.

Then you create an UMG, open this UMG and change it to use your C++ class so you can use your UFUNCTIONs:

UW_2
UW_21920×1020 204 KB

4

Hello, the above answers aren’t addressing the question of “How do I reference a Widget Class in C++”? To clarify this answer references a widget class and not an instanced widget.

To do this, you need to include the “UMG” module in your <projectname>.Build.cs.

Then, in the C++ class create a blueprint readable property for your widget.

UPROPERTY(EditAnywhere,BlueprintReadWrite)
TSubclassOf<UUserWidget> LobbyWidgetClass;

UUserWidget is the parent class for all widget blueprints that are user made in Unreal.

TSubClassOf<ClassName> is a reference to any object that is a subclass of “ClassName”. We need this because whatever widget you have will be a subclass of “UUserWidget”

After this, you will need to assign this property somehow. In my use case, I made a child blueprint class of my C++ class and therefore the property shows up in the details panel of that class like this:
image

Now that it’s a property I can use it in C++ or blueprint functions. Hope that helped someone!
image

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