Unreal: Add Override C++ Event Functions in Blueprints

since: 2016/11/17
update: 2016/11/17
reference:
1. Calling Blueprint Functions from C++ | Orfeas Eleftheriou
2. I touchs: Unreal: Adding a C++ Class
3. I touchs: Unreal: Exposing C++ variables to Blueprints
4. I touchs: Unreal: Exposing C++ functions to Blueprints

A. 新增巨集屬性的函數
     1. 接續 I touchs: Unreal: Exposing C++ functions to Blueprints 的專案

     2. 在 MyActor.h 的類別定義內定義函數:
....
    //@add ######
    UFUNCTION(BlueprintImplementableEvent, Category = "Output")
    void PrintOnScreen(int32 IntToPrint);
....

     3. 在 MyActor.cpp 內呼叫函數: (並傳入參數值)
....
// Called when the game starts or when spawned
void AMyActor::BeginPlay()
{
    Super::BeginPlay();
    //@add ####
    this->PrintOnScreen(7);
}
....

4. 存檔並編譯

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B. 開啟繼承 MyActor 類別的 Blueprint Class
     1. 點選 BP_MyActor, 雙擊滑鼠以開啟

     2. 切換到 Event Graph 頁籤, 點選 Function > Override > Print on Screen

     3. 結果: 產生新的節點

     4. 新增 Print Text 節點, 並連結如下所示:

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C. 回到關卡場景
     1. 將  BP_MyActor 拖拉到場景內

     2. 編譯並執行: (左上方可以看到顯示的數字)