本文章由cartzhang编写,转载请注明出处。 所有权利保留。
文章链接:http://blog.csdn.net/cartzhang/article/details/73189272
作者:cartzhang
一、 UE4 C++ 代码自动生成流程
1. 界面点击生成C++类
图1
先调用 SMenuEntryBlock::OnClicked ,然后调用UI_COMMAND(AddCodeToProject) —-> FMainFrameActionCallbacks::AddCodeToProject(),—-> OpenAddCodeToProjectDialog来打开基类选择界面。
2. 点击Create Class按钮
图2
OnFinished(this, &SNewClassDialog::FinishClicked)
调用函数SNewClassDialog::FinishClicked()—>AddCodeToProject —>GameProjectUtils::AddCodeToProject_Internal(核心都在这里实现)
3. 头文件生成
拼接文件路径信息,GameProjectUtils::GenerateClassHeaderFile来生成头文件的内容。
FinalOutput = "
// Fill out your copyright notice in the Description page of Project Settings.
#pragma once
#include "GameFramework/Pawn.h"
#include "MyPawn.generated.h"
UCLASS()
class HOWTO_VTE_API AMyPawn : public APawn
{
GENERATED_BODY()
public:
// Sets default values for this pawn's properties
AMyPawn();
protected:
// Called when the game starts or when spawned
virtual void BeginPlay() override;
public:
// Called every frame
virtual void Tick(float DeltaTime) override;
// Called to bind functionality to input
virtual void SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent) override;
};
"
4. 生成CPP文件
GenerateClassCPPFile
CPP = // Fill out your copyright notice in the Description page of Project Settings.
#include "HowTo_VTE.h"
#include "MyPawn.h"
// Sets default values
AMyPawn::AMyPawn()
{
// Set this pawn 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 AMyPawn::BeginPlay()
{
Super::BeginPlay();
%CURSORFOCUSLOCATION%
}
// Called every frame
void AMyPawn::Tick(float DeltaTime)
{
Super::Tick(DeltaTime);
}
// Called to bind functionality to input
void AMyPawn::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)
{
Super::SetupPlayerInputComponent(PlayerInputComponent);
}
5. 编译
检测是否可避免全部编译工程,自动热加载,代码首次编译,RecompileModule —>
CheckForFinishedModuleDLLCompile
图3
6. 工程重新加载。
代码生成完毕。
二、 一张图
图4
一图千言
三、 文件生成模板
UE4 代码写的很精妙!
看模板头文件生成:
FString FinalOutput = Template.Replace(TEXT("%COPYRIGHT_LINE%"), *MakeCopyrightLine(), ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%UNPREFIXED_CLASS_NAME%"), *UnPrefixedClassName, ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%CLASS_MODULE_API_MACRO%"), *ModuleAPIMacro, ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%UCLASS_SPECIFIER_LIST%"), *MakeCommaDelimitedList(ClassSpecifierList, false), ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%PREFIXED_CLASS_NAME%"), *PrefixedClassName, ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%PREFIXED_BASE_CLASS_NAME%"), *PrefixedBaseClassName, ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%EVENTUAL_CONSTRUCTOR_DECLARATION%"), *EventualConstructorDeclaration, ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%CLASS_PROPERTIES%"), *ClassProperties, ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%CLASS_FUNCTION_DECLARATIONS%"), *ClassFunctionDeclarations, ESearchCase::CaseSensitive);
FinalOutput = FinalOutput.Replace(TEXT("%BASE_CLASS_INCLUDE_DIRECTIVE%"), *BaseClassIncludeDirective, ESearchCase::CaseSensitive);
CPP文件也类似的。
其中,Tmplate得到是某个继承类的模板字符串,然后通过特定符号来进行替换,生成文件。
模板文件的路径在:UE4_source\UnrealEngine\Engine\Content\Editor\Templates\
比如测试的继承基类为Pawn,他们的模板头文件和CPP文件分别为: PawnClass.h.template 和PawnClass.cpp.template 。
可以自行打开和修改文件。
PawnClass.h.template
%COPYRIGHT_LINE%
#pragma once
%BASE_CLASS_INCLUDE_DIRECTIVE%
#include "%UNPREFIXED_CLASS_NAME%.generated.h"
UCLASS(%UCLASS_SPECIFIER_LIST%)
class %CLASS_MODULE_API_MACRO%%PREFIXED_CLASS_NAME% : public %PREFIXED_BASE_CLASS_NAME%
{
GENERATED_BODY()
public:
// Sets default values for this pawn's properties
%PREFIXED_CLASS_NAME%();
protected:
// Called when the game starts or when spawned
virtual void BeginPlay() override;
public:
// Called every frame
virtual void Tick(float DeltaTime) override;
// Called to bind functionality to input
virtual void SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent) override;
%CLASS_FUNCTION_DECLARATIONS%
%CLASS_PROPERTIES%
};
PawnClass.cpp.template
%COPYRIGHT_LINE%
#include "%MODULE_INCLUDE_PATH%"
#include "%UNPREFIXED_CLASS_NAME%.h"
%ADDITIONAL_INCLUDE_DIRECTIVES%
// Sets default values
%PREFIXED_CLASS_NAME%::%PREFIXED_CLASS_NAME%()
{
// Set this pawn 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 %PREFIXED_CLASS_NAME%::BeginPlay()
{
Super::BeginPlay();
%CURSORFOCUSLOCATION%
}
// Called every frame
void %PREFIXED_CLASS_NAME%::Tick(float DeltaTime)
{
Super::Tick(DeltaTime);
}
// Called to bind functionality to input
void %PREFIXED_CLASS_NAME%::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)
{
Super::SetupPlayerInputComponent(PlayerInputComponent);
}
%ADDITIONAL_MEMBER_DEFINITIONS%
是不是可以自定义头文件呢,估计可以。暂时没有研究。
UE4 工程量太大了,什么样脑子才能架构这玩意啊,他们都是天才!
UE4Paragon游戏人物截图!
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