UE5 slate BlankProgram独立程序系列

源码版Engine\Source\Programs\中copy BlankProgram文件夹，重命名为ASlateLearning，修改所有文件命名及内部名称。

ASlateLearning.Target.cs

// Copyright Epic Games, Inc. All Rights Reserved.using UnrealBuildTool;
using System.Collections.Generic;[SupportedPlatforms(UnrealPlatformClass.All)]
public class ASlateLearningTarget : TargetRules
{public ASlateLearningTarget(TargetInfo Target) : base(Target){Type = TargetType.Program;IncludeOrderVersion = EngineIncludeOrderVersion.Latest;LinkType = TargetLinkType.Monolithic;LaunchModuleName = "ASlateLearning";bBuildDeveloperTools = false;bool bDebugOrDevelopment = Target.Configuration == UnrealTargetConfiguration.Debug || Target.Configuration == UnrealTargetConfiguration.Development;//bBuildWithEditorOnlyData = Target.Platform.IsInGroup(UnrealPlatformGroup.Desktop) && bDebugOrDevelopment;bBuildWithEditorOnlyData = true;bCompileAgainstEngine = false;bCompileAgainstCoreUObject = true;bCompileAgainstApplicationCore = true;bCompileICU = false;bIsBuildingConsoleApplication = true;}
}

ASlateLearning.Build.cs

// Copyright Epic Games, Inc. All Rights Reserved.using UnrealBuildTool;public class ASlateLearning : ModuleRules
{public ASlateLearning(ReadOnlyTargetRules Target) : base(Target){PublicIncludePaths.Add("Runtime/Launch/Public");PrivateIncludePaths.Add("Runtime/Launch/Private");PrivateDependencyModuleNames.AddRange(new string[]{"AppFramework","Core","ApplicationCore","Projects","Slate","SlateCore","StandaloneRenderer",});}
}

 ASlateLearning.cpp

// Copyright Epic Games, Inc. All Rights Reserved.#include "ASlateLearning.h"#include "RequiredProgramMainCPPInclude.h"
#include "StandaloneRenderer.h"DEFINE_LOG_CATEGORY_STATIC(LogASlateLearning, Log, All);IMPLEMENT_APPLICATION(LogASlateLearning, "ASlateLearning");INT32_MAIN_INT32_ARGC_TCHAR_ARGV()
{GEngineLoop.PreInit(ArgC, ArgV);FSlateApplication::InitializeAsStandaloneApplication(GetStandardStandaloneRenderer());FSlateApplication::InitHighDPI(true);const TSharedPtr<SWindow> MainWindow = SNew(SWindow).ClientSize(FVector2D(800, 600));FSlateApplication::Get().AddWindow(MainWindow.ToSharedRef());while (!IsEngineExitRequested()){BeginExitIfRequested();FSlateApplication::Get().PumpMessages();FSlateApplication::Get().Tick();}FEngineLoop::AppExit();return 0;
}

运行后会出现创建的窗口，后面继续扩展

// Copyright Epic Games, Inc. All Rights Reserved.#include "ASlateLearning.h"#include "RequiredProgramMainCPPInclude.h"
#include "StandaloneRenderer.h"DEFINE_LOG_CATEGORY_STATIC(LogASlateLearning, Log, All);IMPLEMENT_APPLICATION(LogASlateLearning, "ASlateLearning");INT32_MAIN_INT32_ARGC_TCHAR_ARGV()
{GEngineLoop.PreInit(ArgC, ArgV);FSlateApplication::InitializeAsStandaloneApplication(GetStandardStandaloneRenderer());FSlateApplication::InitHighDPI(true);const TSharedPtr<SWindow> MainWindow = SNew(SWindow).ClientSize(FVector2D(800, 600))[SNew(SHorizontalBox) + SHorizontalBox::Slot()[SNew(SButton).Text(NSLOCTEXT("L10N", "Key", "Button Content"))]];FSlateApplication::Get().AddWindow(MainWindow.ToSharedRef());while (!IsEngineExitRequested()){BeginExitIfRequested();FSlateApplication::Get().PumpMessages();FSlateApplication::Get().Tick();}FEngineLoop::AppExit();return 0;
}

运行后窗口样式，button太大因为Slot默认的对其策略是HAlign::Fill，VAlign::Fill，调整后的这部分代码应该是

 使用SOverlay::FOverlaySlot* Slot;个Slot的指针，用.Expose(Slot)获取指针，Expose方法填入一个插槽指针并将其返回，此后，我们通过APi可以获得一个SWidget的引用，此时的代码应该是这样了

// Copyright Epic Games, Inc. All Rights Reserved.#include "ASlateLearning.h"#include "RequiredProgramMainCPPInclude.h"
#include "StandaloneRenderer.h"DEFINE_LOG_CATEGORY_STATIC(LogASlateLearning, Log, All);IMPLEMENT_APPLICATION(LogASlateLearning, "ASlateLearning");INT32_MAIN_INT32_ARGC_TCHAR_ARGV()
{GEngineLoop.PreInit(ArgC, ArgV);FSlateApplication::InitializeAsStandaloneApplication(GetStandardStandaloneRenderer());FSlateApplication::InitHighDPI(true);SOverlay::FOverlaySlot* Slot;const TSharedPtr<SWindow> MainWindow = SNew(SWindow).ClientSize(FVector2D(800, 600))[SNew(SOverlay)+ SOverlay::Slot().HAlign(HAlign_Left).VAlign(VAlign_Top).Expose(Slot)[SNew(SHorizontalBox)+ SHorizontalBox::Slot().HAlign(HAlign_Left).VAlign(VAlign_Top)[SNew(SButton).Text(NSLOCTEXT("L10N", "Key", "Button Content"))]]];SWidget& slotwidget = Slot->GetWidget().Get();SHorizontalBox& HorizontalBox = static_cast<SHorizontalBox&>(slotwidget);for (int i = 0; i <5;++i){HorizontalBox.AddSlot()[SNew(SHorizontalBox)+ SHorizontalBox::Slot().HAlign(HAlign_Left).VAlign(VAlign_Top)[SNew(SButton).Text(NSLOCTEXT("L10N", "Key", "Button Content"))]];}FSlateApplication::Get().AddWindow(MainWindow.ToSharedRef());while (!IsEngineExitRequested()){BeginExitIfRequested();FSlateApplication::Get().PumpMessages();FSlateApplication::Get().Tick();}FEngineLoop::AppExit();return 0;
}

 运行后的窗口变成了

 可以为每个Button添加一些方法，通过OnClicked_Lambda之类的方法