UE4 c++ 实现委托

心已赠人 2022-04-15 02:25 375阅读 0赞

### UE4 c++ 实现委托 ###

*  讲道理
 *  实例
 *   *  创建测试用例
     *  运行效果如下

# 讲道理 #

ue4 的委托和c\# 中的一样，delegate本质上属于可存储一个或多个函数指针以及参数的特殊类。

# 实例 #

我们在这里实现一个简单的委托

## 创建测试用例 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW54aWFvamllX2Jsb2c_size_16_color_FFFFFF_t_70]  
代码如下

//.h   
    // Fill out your copyright notice in the Description page of Project Settings.
    #pragma once
    #include "CoreMinimal.h"
    #include "GameFramework/Actor.h"
    #include "MyActor.generated.h"
    //=========定义委托========
    class FMyReceiveDelegateEvent;
    DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FMyReceiveDelegateEvent, FString, Value1, FString, Value2);
    //=========定义委托========
    UCLASS()
    class ASYNCLOADASSET_API AMyActor : public AActor
    {
        
           GENERATED_BODY()
           
    public:       
           // Sets default values for this actor's properties
           AMyActor();
    protected:
           // Called when the game starts or when spawned
           virtual void BeginPlay() override;
    public:       
           // Called every frame
           virtual void Tick(float DeltaTime) override;
    public:
           //======声明委托======
           UPROPERTY(BlueprintAssignable, Category = "Event")
                  FMyReceiveDelegateEvent  MyReceiveDelegateEvent;
           //======声明委托======
           //======调用委托函数的执行===========
           UFUNCTION(BlueprintCallable, Category ="aa")
           void sendSomething();
           //======调用委托函数的执行===========
    };
    
    //.cpp
    // Fill out your copyright notice in the Description page of Project Settings.
    #include "MyActor.h"
    // Sets default values
    AMyActor::AMyActor()
    {
        
           // Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
           PrimaryActorTick.bCanEverTick = true;
    }
    // Called when the game starts or when spawned
    void AMyActor::BeginPlay()
    {
        
           Super::BeginPlay();
           
    }
    // Called every frame
    void AMyActor::Tick(float DeltaTime)
    {
        
           Super::Tick(DeltaTime);
    }
    void AMyActor::sendSomething()
    {
        
            //========调用委托并附上参数============
           this->MyReceiveDelegateEvent.Broadcast("aa","bb");
    }

新建一个actor，继承上述actor，并且编写测试  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW54aWFvamllX2Jsb2c_size_16_color_FFFFFF_t_70 1]

## 运行效果如下 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW54aWFvamllX2Jsb2c_size_16_color_FFFFFF_t_70 2]

详细解读可以看看 [这篇][Link 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW54aWFvamllX2Jsb2c_size_16_color_FFFFFF_t_70]: /images/20220415/a1f667abaf494ef097f7d69bac20884c.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW54aWFvamllX2Jsb2c_size_16_color_FFFFFF_t_70 1]: /images/20220415/651080ce019449cd880dbb9ef839b6bf.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW54aWFvamllX2Jsb2c_size_16_color_FFFFFF_t_70 2]: /images/20220415/9d2085a01383484aa50fdf2787542653.png
[Link 1]: https://blog.csdn.net/aslgsx12315/article/details/51169848