UE C++ Cookbook

打印函数

#pragma once

#include "CoreMinimal.h"

DECLARE_LOG_CATEGORY_EXTERN(MM, Log, All);

inline DEFINE_LOG_CATEGORY(MM);


// FString
template <typename T>
void TPrint(FString DataName, const T& Data)
{
    UE_LOG(MM, Log, TEXT("%s : %s"), *DataName, *Data);
}

template <>
inline void TPrint<float>(FString DataName, const float& Data)
{
    UE_LOG(MM, Log, TEXT("%s : %.3f"), *DataName, Data);
}

template <>
inline void TPrint<double>(FString DataName, const double& Data)
{
    UE_LOG(MM, Log, TEXT("%s : %.3f"), *DataName, Data);
}

template <>
inline void TPrint<int>(FString DataName, const int& Data)
{
    UE_LOG(MM, Log, TEXT("%s : %d"), *DataName, Data);
}

template <>
inline void TPrint<bool>(FString DataName, const bool& Data)
{
    UE_LOG(MM, Log, TEXT("%s : %s"), *DataName, Data ? TEXT("True") : TEXT("False"));
}


#define MPrint(var) UE_LOG(MM, Log, TEXT("%s"), *(var));
#define MMPrint(var) TPrint<std::decay_t<decltype(var)>>(TEXT(#var), var)

struct FSeparatorRAII
{
    FSeparatorRAII(const FString& InName)
        : Name(InName)
    {
        FString Sep = FString(TEXT("---------")) + Name + FString(TEXT("----------"));
        MPrint(Sep);
    }

    ~FSeparatorRAII()
    {
        MPrint(FString(L"---------") + Name + FString(L"----------"));
    }

    FString Name;
};

FString、FName

void BlinkEditorModule::TestFString()
{
    FString Str("aaa");
    FString WStr(TEXT("Aaa"));
    MMPrint(WStr);
    MMPrint(Str.Len());
    MMPrint(WStr.Len());
    MMPrint(WStr == Str); // default: Ignore_Case
    MMPrint(WStr.Equals(Str)); // default: Case_Sensitive

    // API
    FString S = L"www.google.com";

    // Split
    {
        FSeparatorRAII Sep(FString(L"Split"));
        FString left, right;
        S.Split(".", &left, &right);
        MMPrint(left);
        MMPrint(right);
        S.Split(L".", &left, &right);
        MMPrint(left);
        MMPrint(right);
    }

    // Append
    {
        FSeparatorRAII Sep(FString("Append"));
        S.Append(L"?我为什么这么帅");
        MPrint(S);
    }

    // SubString Methods
    {
        FSeparatorRAII Sep(FString("SubString Methods"));
        int32 Idx;

        S.FindChar('?', Idx);
        MMPrint(Idx);

        MMPrint(S.Mid(Idx));
        MMPrint(S.Mid(Idx, 3));
        MMPrint(S.RightChop(Idx)); // 去掉右侧n个字符，返回剩下的
        MMPrint(S.Right(Idx)); // 返回右侧n个字符
        MMPrint(S.LeftChop(2)); // 去掉右侧n个字符，返回剩下的
        MMPrint(S.Left(2)); // 返回左侧n个字符
    }

    {
        FSeparatorRAII Sep(FString("FName"));
        FName N1(FString("yes"));
        FName N2(FString("Yes"));
        MPrint(N1.ToString());
        MPrint(N2.ToString());
        MMPrint(N1 == N2);
    }
}