UE5 runtime模式下自定义视口大小和位置并跟随分辨率自适应缩放

本文旨在解决因UI问题导致屏幕中心位置不对的问题
处理前的现象：如果四周UI透明度都为1，那么方块的位置就不太对，没在中心

处理后的现象：

解决办法：自定义大小和视口偏移
创建一个基于子系统的类或者蓝图函数库(什么类不重要，你调的到就行)
.h

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

#pragma once

#include "CoreMinimal.h"
#include "Subsystems/GameInstanceSubsystem.h"
#include "CustomGameViewSizeSub.generated.h"

/**
 * 
 */
class FViewport;

//定义当视口大小发生变化时的代理
DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnViewportResized);

UCLASS()
class CUSTOMGAMEVIEWSIZE_API UCustomGameViewSizeSub : public UGameInstanceSubsystem
{
	GENERATED_BODY()

public:

	UPROPERTY(BlueprintAssignable, Category = "Delegate")
		FOnViewportResized OnViewportResized;

public:

	void ViewportResize(FViewport* Viewport, uint32 Size);

	virtual void Initialize(FSubsystemCollectionBase& Collection) override;

	UFUNCTION(BlueprintCallable, Category = "Fun Tool")
		void AdjustViewportSize(FMargin margin);
};

.cpp

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


#include "CustomGameViewSizeSub.h"
#include "UnrealClient.h"
#include "Engine/Engine.h"
#include "Engine/GameViewportClient.h"

void UCustomGameViewSizeSub::Initialize(FSubsystemCollectionBase& Collection)
{
    GEngine->GameViewport->Viewport->ViewportResizedEvent.AddUObject(this, &UCustomGameViewSizeSub::ViewportResize);
}

void UCustomGameViewSizeSub::ViewportResize(FViewport* Viewport, uint32 Size)
{
    OnViewportResized.Broadcast();
}

void UCustomGameViewSizeSub::AdjustViewportSize(FMargin margin)
{
    UE_LOG(LogTemp, Log, TEXT(" AdjustViewportSize "));
    if (GEngine->GameViewport)
    {
        FVector2D ViewportSize;
        GEngine->GameViewport->GetViewportSize(ViewportSize);

        if (ViewportSize.X > 0 && ViewportSize.Y > 0)
        {
            //视口大小缩放
            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].SizeX = margin.Right / ViewportSize.X;
            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].SizeY = margin.Bottom / ViewportSize.Y;
            //基于视口原点偏移，原点是左上角(0,0)
            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].OriginX = margin.Left / ViewportSize.X;
            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].OriginY = margin.Top / ViewportSize.Y;
        }
    }
}

UMG设计图：
逻辑实现：