Question

此刻，我正在使用虚幻引擎的HTTP模块，并编写了一个类来从Web服务中查询天气信息。首先，我创建了一个通用的HTTP服务类，如下所示：

#pragma once

#include "CoreMinimal.h"
#include "Runtime/Online/HTTP/Public/Http.h"
#include "Json.h"
#include "HTTPService.generated.h"

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FHTTPOnResponseRecievedDelegate, const FString&, HttpData);

UCLASS()
class THMVRAYPLUGIN_API UHTTPService : public UClass
{
    GENERATED_BODY()

private:
    FHttpModule * Http;
    FString AuthorizationHeader = "Authorization";
    void SetAuthorizationHash(FString Hash, TSharedRef<IHttpRequest>& Request);
    void SetRequestHeaders(TSharedRef<IHttpRequest>& Request);
    bool ResponseIsValid(FHttpResponsePtr Response, bool bWasSuccessful);
    virtual void OnResponseReceived(FHttpRequestPtr Request, FHttpResponsePtr Response, bool bWasSuccesful);
    void Send(TSharedRef<IHttpRequest>& Request);

public:    
    UHTTPService();
    FHTTPOnResponseRecievedDelegate responseReceived;
    TSharedRef<IHttpRequest> GetRequest(FString request);
};

我为OnResponseReceived事件声明了一个动态多播委托。此方法广播接收到的JSON字符串：

void UHTTPService::OnResponseReceived(FHttpRequestPtr Request, FHttpResponsePtr Response, bool bWasSuccesful)
{
    if (ResponseIsValid(Response, bWasSuccesful)) {
        FString JSONString = Response->GetContentAsString();
        UE_LOG(LogTemp, Warning, TEXT("Http Response: %s"), *JSONString);
        responseReceived.Broadcast(JSONString);
    }

}

之后，我为特定的Web API创建了HTTPService类的子类：

#pragma once

#include "CoreMinimal.h"
#include "HTTPService.h"
#include "HTTPWeatherService.generated.h"

UCLASS()
class THMVRAYPLUGIN_API UHTTPWeatherService : public UHTTPService
{
    GENERATED_BODY()

private:
    FString APIBaseURL = "xxxx";
    FString APIKey = "xxxx";

public:    
    UHTTPWeatherService();
    void queryWeatherAPIForCoords(float lat, float lon);

};

现在，我想将其用于我编写的自定义演员。在详细信息面板自定义中，我创建了一个自定义行来容纳这样的按钮：

//....
        auto OnWeatherButtonClicked = [myActor]
        {
            float lat = myActor->latitude;
            float lon = myActor->longitude;
            UHTTPWeatherService * weatherService = NewObject<UHTTPWeatherService>();
            weatherService->queryWeatherAPIForCoords(lat, lon);
            return FReply::Handled();
        };

        experimentalGroup.AddWidgetRow()
            .ValueContent()
            [
                SNew(SButton)
                .Text(LOCTEXT("Current weather", "Get weather at current location"))
                .ToolTipText(LOCTEXT("Uses a web api to get information on the current weather at the current coords","Uses a web api to get information on the current weather at the current coords"))
                .OnClicked_Lambda(OnWeatherButtonClicked)
            ];
//...

单击按钮时，它会触发查询Web api的功能。我现在想做的是将一个函数绑定到动态多播委托。我想在收到响应时触发自定义角色的方法。你会怎么做？什么是好的程序结构？有人可以提供一段代码作为参考吗？

预先感谢=）

Answer 1

我设法使其使用DECLARE_MULTICAST_DELEGATE_OneParam而不是DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam。

虚幻引擎4：动态多播委托绑定

1 个答案: