[游戏开发]UE4简单的异步线程

1. 创建FNonAbandonableTask配合事件代理

DECLARE_DYNAMIC_DELEGATE_OneParam(FSwitchQGCJoystickDelegate, EJoystick, type);
class TaskExample : public FNonAbandonableTask
{
	//定义需要的属性
	/*Code*/
public:
	FSwitchQGCJoystickDelegate SwitchJoystickDelegate;
	EJoystick Type;

	//构造函数，根据需要初始化数据
	TaskExample(FSwitchQGCJoystickDelegate switchJoystickDelegate, EJoystick type = EJoystick::EJ_FengHuang)
	{
		this->SwitchJoystickDelegate = switchJoystickDelegate;
		this->Type = type;
		/*Code*/
	}

	FORCEINLINE TStatId GetStatId() const
	{
		RETURN_QUICK_DECLARE_CYCLE_STAT(TaskExample, STATGROUP_ThreadPoolAsyncTasks);
	}

	/*需要使用Task完成的任务*/
	void DoWork()
	{
		/*Code*/
        // 调用UI中的函数  必须主线程执行
		AsyncTask(ENamedThreads::GameThread, [&]() {
			/*Code*/
		});
	}
};



调用方式：
//(new FAutoDeleteAsyncTask<TaskExample>())->StartSynchronousTask();

方法2：使用UBlueprintAsyncActionBase

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintAsyncActionBase.h"
#include "AirsimPx4ConnectBPLibrary.h"
#include "SwitchQgcJoystick.generated.h"


extern enum class EJoystick :uint8;

/**
 * 
 */
UCLASS()
class AIRSIMPX4CONNECT_API USwitchQgcJoystick : public UBlueprintAsyncActionBase
{
	
	GENERATED_BODY()
public:
	DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FBPPin_Result, EJoystick, JoystickType);
	/** 输出针脚1 */
	UPROPERTY(BlueprintAssignable)
	FBPPin_Result OnComplete;

	EJoystick ActiveJoystickType;

public:
	/** 蓝图节点:负责NewOBject 蓝图节点(创建工厂模式) */
	UFUNCTION(BlueprintCallable, meta = (BlueprintInternalUseOnly = "true", WorldContext = "WorldContextObject", Category = "AirsimPx4Connect"))
		static USwitchQgcJoystick* SwitchQgcJoystickAsync(UObject* WorldContextObject, EJoystick Type = EJoystick::EJ_FengHuang);
protected:
	/** 程序通过（运行）节点是调用 */
	virtual void Activate() override;
};

// Fill out your copyright notice in the Description page of Project Settings.


#include "SwitchQgcJoystick.h"

USwitchQgcJoystick* USwitchQgcJoystick::SwitchQgcJoystickAsync(UObject* WorldContextObject, EJoystick Type)
{
	USwitchQgcJoystick* Ins = NewObject<USwitchQgcJoystick>();
	Ins->ActiveJoystickType = Type;
	return Ins;
}

void USwitchQgcJoystick::Activate()
{
	//测试逻辑----开新线程，延迟一秒后随机调用成功或失败委托
	Async(EAsyncExecution::ThreadPool, [&]()
		{
			FPlatformProcess::Sleep(1.0f);
			// 该动作必须游戏线程中执行
			AsyncTask(ENamedThreads::GameThread, [&]() {
				this->OnComplete.Broadcast(this->ActiveJoystickType);
				});
		});
}