UE4 游戏窗口前台后台监听_ue4手游切前后台(android)

【原创文章 转载请注明出处】

最近有个需求，记录在窗口切到后台和切回前台时的时间。找了很久，没有具体的方法，光看到有个委托事件也不知道怎么用。查资料+测试了1天，感谢各位大佬对UE 委托DELEGATE的介绍，现把我也把自己关于这部分功能的详细代码方上来，做个记录吧。

由于喜欢在蓝图中实现具体逻辑，所以有些代码可能会有些多余。

这部分比较乱完整的代码会在下面放出来。如果觉得有帮助请给我点个赞，哈哈

就不新建文件了，用自己的项目说了，

在CEditorGameInstance.h中

在开头出 通过委托宏自己定义2个动态多播返回值为viod的委托类型

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnWindowActive);
DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnWindowDeActive);

在类中声明2个公有变量，开放给蓝图使用，之后会在蓝图中对这2个事件进行绑定。

UPROPERTY(BlueprintAssignable)
	FOnWindowActive onWindowActivatedEvent;
UPROPERTY(BlueprintAssignable)
	FOnWindowDeActive onWindowDeactivatedEvent;

之后就是获取窗口的通知，UE自带的窗口通知事件是由SWindow发起的，我们先参考一下有哪些类型 SWindow.h

/** Notification that a window has been activated */
DECLARE_DELEGATE( FOnWindowActivated );
DECLARE_MULTICAST_DELEGATE( FOnWindowActivatedEvent );
 
/** Notification that a window has been deactivated */
DECLARE_DELEGATE( FOnWindowDeactivated );
DECLARE_MULTICAST_DELEGATE( FOnWindowDeactivatedEvent );
 
/** Notification that a window is about to be closed */
DECLARE_DELEGATE_OneParam( FOnWindowClosed, const TSharedRef<SWindow>& );
 
/** Notification that a window has been moved */
DECLARE_DELEGATE_OneParam( FOnWindowMoved, const TSharedRef<SWindow>& );
 
/** Override delegate for RequestDestroyWindow */
DECLARE_DELEGATE_OneParam( FRequestDestroyWindowOverride, const TSharedRef<SWindow>& );
 
/** Called when we need to switch game worlds for a window */
DECLARE_DELEGATE_RetVal_OneParam( int32, FOnSwitchWorldHack, int32 );

我们需要用到的是这两个：

DECLARE_DELEGATE( FOnWindowActivated );
DECLARE_DELEGATE( FOnWindowDeactivated );

回到CEditorGameInstance.h中

在声明2个变量

FOnWindowActivated	onWindowActivedHandle;
FOnWindowDeactivated	onWindowDeactivedHandle;

这样需要的变量就已经定义完了，如图：

之后写绑定函数

​​UFUNCTION(BlueprintCallable, meta = (DisplayName = "Handle Application Actived"), Category = "Application")
    void HandleOnWindowActived();//获取窗口被激活时的信息
UFUNCTION(BlueprintCallable, meta = (DisplayName = "Handle Application Deactived"), Category = "Application")
    void HandleOnWindowDeactived();//获取窗口失效时的信息
    //获得各自信息后调用委托事件(这样蓝图中已经绑定事件的话就会收到信息)
    void OnRequestWindowActived();
    void OnRequestWindowDeactived();

 

//---------------窗口激活时的绑定------------------
void UCEditorGameInstance::HandleOnWindowActived()
{
        //为Handle绑定函数
	onWindowActivedHandle.BindUObject(this, &UCEditorGameInstance::OnRequestWindowActived);
	if (GEngine)
	{
                //为SWindow设置句柄
		TSharedPtr<SWindow> Application = GEngine->GameViewport->GetWindow();
		Application->SetOnWindowActivated(onWindowActivedHandle);
 
		UE_LOG(LogTemp, Log, TEXT("Application request Actived is handled!"));
	}
	else
	{
		UE_LOG(LogTemp, Warning, TEXT("Can not get viewport reference, handle application Actived request failed!"));
	}
}
 
void UCEditorGameInstance::OnRequestWindowActived()
{
	UE_LOG(LogTemp, Log, TEXT("Application request OnRequestWindowActived is handled!---dcf"));
	if (onWindowActivatedEvent.IsBound())
	{
		onWindowActivatedEvent.Broadcast();
	}
}

 

//---------------窗口失效时的绑定------------------
void UCEditorGameInstance::HandleOnWindowDeactived()
{
	onWindowDeactivedHandle.BindUObject(this, &UCEditorGameInstance::OnRequestWindowDeactived);
	if (GEngine)
	{
		TSharedPtr<SWindow> Application = GEngine->GameViewport->GetWindow();
		Application->SetOnWindowDeactivated(onWindowDeactivedHandle);
 
		UE_LOG(LogTemp, Log, TEXT("Application request Deactived is handled!"));
	}
	else
	{
		UE_LOG(LogTemp, Warning, TEXT("Can not get viewport reference, handle application Deactived request failed!"));
	}
}
 
void UCEditorGameInstance::OnRequestWindowDeactived()
{
	UE_LOG(LogTemp, Log, TEXT("Application request OnRequestWindowDeactived is handled!---dcf"));
	if (onWindowDeactivatedEvent.IsBound())
	{
		onWindowDeactivatedEvent.Broadcast();
	}
}

编译启动项目，到EditorGameInstance蓝图创建函数

 

到自己的项目的第一个Widget界面，初始化的时候调用刚才的方法（我的是登录界面Login_bp）

测试 启动游戏，点击其他区域 在点回窗口 看到日志已经打印出来了

 

完整的C++代码：

.h

#include "Runtime/SlateCore/Public/Widgets/SWindow.h"
 
DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnWindowActive);
DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnWindowDeActive);
 
UCLASS()
class AJDR_API UCEditorGameInstance : public UGameInstance
｛
    GENERATED_UCLASS_BODY()
 
public:
	UFUNCTION(BlueprintCallable, meta = (DisplayName = "Handle Application Actived"), Category = "Application")
		void HandleOnWindowActived();
	void OnRequestWindowActived();
	UFUNCTION(BlueprintCallable, meta = (DisplayName = "Handle Application Deactived"), Category = "Application")
		void HandleOnWindowDeactived();
	void OnRequestWindowDeactived();
 
 
public:
	FOnWindowActivated		onWindowActivedHandle;
	FOnWindowDeactivated	onWindowDeactivedHandle;
	UPROPERTY(BlueprintAssignable)
		FOnWindowActive onWindowActivatedEvent;
	UPROPERTY(BlueprintAssignable)
		FOnWindowDeActive onWindowDeactivatedEvent;
 
｝

.cpp

void UCEditorGameInstance::HandleOnWindowActived()
{
	onWindowActivedHandle.BindUObject(this, &UCEditorGameInstance::OnRequestWindowActived);
	if (GEngine)
	{
		TSharedPtr<SWindow> Application = GEngine->GameViewport->GetWindow();
		Application->SetOnWindowActivated(onWindowActivedHandle);
 
		UE_LOG(LogTemp, Log, TEXT("Application request Actived is handled!"));
	}
	else
	{
		UE_LOG(LogTemp, Warning, TEXT("Can not get viewport reference, handle application Actived request failed!"));
	}
}
 
void UCEditorGameInstance::OnRequestWindowActived()
{
	UE_LOG(LogTemp, Log, TEXT("Application request OnRequestWindowActived is handled!---dcf"));
	if (onWindowActivatedEvent.IsBound())
	{
		onWindowActivatedEvent.Broadcast();
	}
}
 
void UCEditorGameInstance::HandleOnWindowDeactived()
{
	onWindowDeactivedHandle.BindUObject(this, &UCEditorGameInstance::OnRequestWindowDeactived);
	if (GEngine)
	{
		TSharedPtr<SWindow> Application = GEngine->GameViewport->GetWindow();
		Application->SetOnWindowDeactivated(onWindowDeactivedHandle);
 
		UE_LOG(LogTemp, Log, TEXT("Application request Deactived is handled!"));
	}
	else
	{
		UE_LOG(LogTemp, Warning, TEXT("Can not get viewport reference, handle application Deactived request failed!"));
	}
}
 
void UCEditorGameInstance::OnRequestWindowDeactived()
{
	UE_LOG(LogTemp, Log, TEXT("Application request OnRequestWindowDeactived is handled!---dcf"));
	if (onWindowDeactivatedEvent.IsBound())
	{
		onWindowDeactivatedEvent.Broadcast();
	}
}