UE4 C++ UMG框架搭建

一、基础UI

       UMG全程叫做Unreal Motion Graphics UI Designer，是一种开发UI的工具。使用Unreal来进行UI开发，主要有两种方式，一种是Slate，另一种就是UMG，UMG是对Slate的一种包装。使用Slate进行UI开发，难度还是非常大的，需要使用C++来进行页面设计，调试非常不方便。UMG对初级开发者就非常的友好，一种所见即所得的开发模式，逻辑也可以直接使用蓝图进行编写。

      虚幻引擎中分类分为两类：第一类是2DUI也就是显示在平面上的UI界面，第二类是3DUI显示在3D空间上的3D界面。

  2DUI：屏幕上看到的一些文字数字等

3DUI：3D空间上的UI

两者区别：

2DUI创建方式为：creatwidget节点

3DUI的创建方式是，先创建Actor，将Widget以组件的方式加载到Actor里面

 

二、常用的UI空间button、image、text

          

    第一部分：Anchors锚点可以设置控件的对其方式和锚点位置，尺寸大小等

    

    第二部分：Appearance外观可以设置控件的图片样式，正常的样式，点击的样式，放上去的样式，点击的声音等,每个控件都有自己的样式，可以根据自己的喜好设置

     

    第三部分：点击事件可以通过点击来实现不通的功能

    

三、案例

  创建C++接口 interface命名为StateInterface

 在C++里面写两个接口

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

#pragma once

#include "CoreMinimal.h"
#include "UObject/Interface.h"
#include "StateInterface.generated.h"

// This class does not need to be modified.
UINTERFACE(MinimalAPI)
class UStateInterface : public UInterface
{
	GENERATED_BODY()
};

/**
 * 
 */
class NEWOBJECT_API IStateInterface
{
	GENERATED_BODY()

	// Add interface functions to this class. This is the class that will be inherited to implement this interface.
public:

	virtual void EnterState() = 0;
	virtual void ExitState() = 0;
};

C++创建UserWidget命名为BaseStateWidget

 继承接口，重写虚函数

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

#pragma once

#include "CoreMinimal.h"
#include "Blueprint/UserWidget.h"
#include "StateInterface.h"
#include "BaseStateWidget.generated.h"

/**
 * 
 */
UCLASS()
class NEWOBJECT_API UBaseStateWidget : public UUserWidget,public IStateInterface
{
	GENERATED_BODY()

public:
	virtual void EnterState() override;
	virtual void ExitState() override;
	
	UFUNCTION(BlueprintNativeEvent,BlueprintCallable,Category = "State Pattern")
		void OnEnterState();
	UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category = "State Pattern")
		void OnExitState();
};

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


#include "BaseStateWidget.h"

void UBaseStateWidget::EnterState()
{
	OnEnterState();
}

void UBaseStateWidget::ExitState()
{
	OnExitState();
}

void UBaseStateWidget::OnEnterState_Implementation()
{
	AddToViewport();
}

void UBaseStateWidget::OnExitState_Implementation()
{
	RemoveFromParent();
}

C++创建Actor命名为UIStateManager

  

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

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "BaseStateWidget.h"
#include "Kismet/GameplayStatics.h"
#include "UIStateManager.generated.h"

UCLASS()
class NEWOBJECT_API AUIStateManager : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	AUIStateManager();

protected:
	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void Tick(float DeltaTime) override;

	UFUNCTION(BlueprintCallable, Category = "State Pattern")
		void EnterState(TSubclassOf StateWidgetClass);

	UFUNCTION(BlueprintCallable, Category = "State Pattern")
		void ExitAllState();

	UPROPERTY(BlueprintReadWrite,Category = "State Pattern")
		UBaseStateWidget* CurrentStateWidget;

private:
	TMap,UBaseStateWidget*> WidgetIntsance;
};

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


#include "UIStateManager.h"

// Sets default values
AUIStateManager::AUIStateManager()
{
 	// 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 AUIStateManager::BeginPlay()
{
	Super::BeginPlay();
	
}

// Called every frame
void AUIStateManager::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

}

void AUIStateManager::EnterState(TSubclassOf StateWidgetClass)
{
	if (CurrentStateWidget != nullptr)
	{
		CurrentStateWidget->ExitState();
	}
	if (WidgetIntsance.Contains(StateWidgetClass))
	{
		CurrentStateWidget = WidgetIntsance.FindRef(StateWidgetClass);
	}
	else
	{
		APlayerController* PC = UGameplayStatics::GetPlayerController(GetWorld(),0);
		CurrentStateWidget = CreateWidget(PC,StateWidgetClass);
		WidgetIntsance.Add(StateWidgetClass,CurrentStateWidget);
	}
	CurrentStateWidget->EnterState();
}

void AUIStateManager::ExitAllState()
{
	for (auto& Elem:WidgetIntsance)
	{
		(Elem.Value)->ExitState();
	}
}

创建UMG继承自刚刚创建的BaseStateWidget

 

 样式你可以自己设计

创建蓝图

 

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