UE 最全FString字符串与各格式转换 输出
一、UE4 Source Header References
CString.h UnrealString.h NameTypes.h StringConv.h (TCHAR_TO_ANSI etc)CString.h可以查到更多，如
atoi64 (string to int64) Atod (string to double precision float)二、日志打印
1.输出字符串到output log中
1.1 最普通的三种
FString filePath UE_LOG(LogTemp, Log, TEXT("Hello,World!")); UE_LOG(LogTemp, Warning, TEXT("Hello,World!")); UE_LOG(LogTemp, Error, TEXT("Hello,World!"));1.2 %d打印int，%f打印float，%s string
前面加throttle是为了知道打印的对象
UE_LOG(LogTemp，Log，TEXT("throttle %d"), throttle); //输出：throttle 1532 FString filePath UE_LOG(LogTemp, Log, TEXT("%s"), *filePath);1.3 自定义 分类的名字 的log
.h DECLARE LOG CATEGORY EXTERN(MyLog,Log，All); .cpp DEFINE_LOG_CATEGORY(MyLog); UE_LOG(MyLog,Warning,TEXT ("Success")); 输出： MyLog:Warning:Success2.输出字符串到屏幕上
FString filePath; GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, FString::Printf(TEXT("DLL_Init"))); GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, FString::Printf(TEXT("%s"), *filePath));三、FString
3.1 FString To FNames
不可靠，因为FName不区分大小写，所以转换存在丢失
//字符串 FString TheString = "Hello，world"; //将FString转换为FName FName ConvertedFString = FName(*TheString);3.2 FString To FText
FString TheString = "Hello，world"; FText ConvertedFSting=FText::FromSting(TheString);3.3 FString To Array[uint8]
//方法1 FString JsonStr; TArray<uint8> content; content.SetNum(JsonStr.Len()); memcpy(content.GetData(), TCHAR_TO_ANSI(*JsonStr), JsonStr.Len()); //方法2 FString StrData; const TCHAR* StrPtr = *StrData; FTCHARToUTF8 UTF8String(StrPtr); int32 CTXSize = UTF8String.Length(); TArray<uint8> URLData; URLData.SetNum(CTXSize); memcpy(URLData.GetData(), UTF8String.Get(), CTXSize);3.4 FString To char*
FString TheString = "Hello，world"; char* MyCharPtr = TCHAR_TO_UTF8(*MyFString);3.5 FString To const char *
const char *plainText= TCHAR_TO_ANSI(*aes_content);3.6 FString To TCHAR*
FString s="a"; TCHAR* t=*s;3.7 FString To std::string
#include <string> FString UE4Str = TEXT("Flowers"); std::string MyStdString = TCHAR_TO_UTF8(*UE4Str);3.8 FString To JsonObject
处理Json需要在.Build.cs中添加Json模块
PrivateDependencyModuleNames.AddRange( new string[] { "CoreUObject", "Engine", "Slate", "SlateCore", "Json", // ... add private dependencies that you statically link with here ... } );//注意String中使用双引号 FString JsonStr = TEXT("{\"key\":\"value\",\"key2\":\"value2\"}"); TSharedPtr<FJsonObject> JsonObject = MakeShareable(new FJsonObject); TSharedRef<TJsonReader<>> Reader = TJsonReaderFactory<>::Create(JsonStr); FJsonSerializer::Deserialize(Reader,JsonObject); //JsonObject就是Json3.9 FString To bool
FString TheString = "123.021"; bool MyBool = MyFString.ToBool();3.10FString To int32
FString TheString = "123.021"; //注意，Atoi和Atof是静态函数，所以使用语法FCString：：TheFunction调用它：) int32 MyShinyNewInt = FCString::Atoi(*TheString);3.11 FString To int64
FString TheString = "12312345678789561234879"; //注意，Atoi64是静态函数，所以使用语法FCString::TheFunction调用它：) int64 MyShinyNewInt = FCString::Atoi64(*TheString);3.12 FString To float
FString TheString = "123.021"; //注意，Atoi和Atof是静态函数，所以使用语法FCString：：TheFunction调用它：) float MyShinyNewFloat = FCString::Atof(*TheString);3.13 FString To double
//函数方式 bool UDoubleFunction::FStringToDouble(FString str,double &num) { std::string numString = TCHAR_TO_UTF8(*str); double b = atof(numString.c_str()); if (b == NULL) { return false; } num =b; return true; } //直接转换 FString TheString = "123.021"; //注意，Atod是静态函数，所以使用语法FCString：：TheFunction调用它：) double MyShinyNewFloat = FCString::Atod(*TheString); //FString转String转Double FString str = "113.5246854"; std::string numString = TCHAR_TO_UTF8(*str); double b = atof(numString.c_str());3.14 转换 To FString
//int FString NewString = FString::FromInt(MyInt); //float //double ----只能精确到小数点后6位 FString VeryCleanString = FString::SanitizeFloat(MyFloat); //bool FString MyFString = MyBool?TEXT("true") :TEXT("false"); //FVector FString MyFString = MyVector.ToString(); //FVector2D FString MyFString = MyVector2D.ToString(); //FRotator FString MyFString = MyRotator.ToString(); //FLinearColor FString MyFString = MyLinearColor.ToString(); //UObject FString MyFString = (MyObj != NULL) ? MyObj->GetName() : FString(TEXT("None")); //FMatrix FMatrix rotationMatrix(FPlane(0,1,2,3),FPlane(4,5,6,7),FPlane(8,9,10,11),FPlane(12,13,14,15)); FString str = rotationMatrix.ToString();3.15 double To FString
//直接转换：精确到小数点后6位 return FString::SanitizeFloat(numeral.dou); //double→string→FString精确到小数点后6位 std::string Str = std::to_string(numeral.dou); FString string = UTF8_TO_TCHAR(Str.c_str()); //输出有效位数15位 #include <iostream> #include <string> #include <sstream> #include <iomanip> string str; double d = numeral.dou; stringstream ss; ss << setprecision(15) << d; str = ss.str(); FString string = UTF8_TO_TCHAR(str.c_str()); //指定小数点后几位 --注：double的有效位数只有16位，小数点算一位 double doub = 9999.1234567891011121314; FString TimeDesc = FString::Printf(TEXT("%.15f"), doub); //9999.1234567891006013.16 bytes To FString
FString fstr; for (int i(0); i < FaceArray.Num() * 4; ++i) { FString tmpStr; ByteToHex(f_arrbytes[i], tmpStr); fstr.Append(tmpStr); } UE_LOG(LogTemp, Log, TEXT("%S"), *fstr);3.17 FArrayReaderPtr to FString
uint8 data[512]; FMemory::Memzero(data, 512); FMemory::Memcpy(data, ArrayReaderPtr->GetData(), ArrayReaderPtr->Num()); FString str = ((const char*)data);3.18 Array[uint8] to FString
TArray<uint8> content; const std::string cstr(reinterpret_cast<const char*>(content.GetData()), content.Num()); FString frameAsFString = cstr.c_str(); UE_LOG(VRSLog, Warning, TEXT("%s"), *frameAsFString);3.19FString To MD5（FString）
FString str = TEXT("someStuff"); FString md5 = FMD5::HashAnsiString();3.20 FString To Ascii/Unicode
FString str = TEXT("123苹果"); int32 ascii = (int32)Source[4]; //数字代表序号 int32 ascii2 = (int32)Source.GetCharArray()[4]; //或者第二种写法3.21 FString From Ascii/Unicode
FString str; int32 ascii = 49; //1的ascii是49。 中文 中的编码是20013 str.AppendChar(Ascii); //如果ascii为20013，转换出来时中四、FName
4.1 FName To FString
FName str = FName(TEXT("hello")); FString fstr = str.ToString();4.2 FName To FText
FName str = FName(TEXT("hello")); FText = FText::FromName(str);五、FText
FText To FString
//不可靠，在一些语言中存在损耗 FString Name = MyText.ToString();六、TChar*
TChar* 与 char* 的互相转换
主要是使用下面的四个宏定义。
TCHAR_TO_ANSI(*str) ANSI_TO_TCHAR(*str) TCHAR_TO_UTF8(*str) UTF8_TO_TCHAR(*str)七、std::string
std::string To FString
#include <string> std::string MyStdString = "Happy"; FString HappyString(UTF8_TO_TCHAR(MyStdString.c_str())); //可防止string的中文转换出错To string函数
c++11标准增加了全局函数std::to_string: string to_string (int val); string to_string (long val); string to_string (long long val); string to_string (unsigned val); string to_string (unsigned long val); string to_string (unsigned long long val); string to_string (float val); //只能精确到小数点后6位 string to_string (double val); //只能精确到小数点后6位 string to_string (long double val);string To函数
string To int
std::string str = "123"; int n = atoi(str.c_str()); cout<<n; //123double->string
//有效位数20位 ---据说待考证 char buffer[100]; double b=1245683.141592653; int ndight=20;//有效数字位数 gcvt(b,ndight,buffer); cout<<buffer<<endl; //一般使用方法:只能精确到小数点后6位 #include <string> using namespace std; double d = 3.1415926535897932384; string str = std::to_string(d); cout << str << std::endl; // 3.141593 //使用stringstream，在输入流时使用setprecision设置精度，需包含头文件 <iomanip> //精度保持到小数点后15位 #include <iostream> #include <string> #include <sstream> #include <iomanip> using namespace std; std::stringstream ss; ss << setprecision(15) << d; str = ss.str(); cout << str << std::endl; // 3.14159265358979 //对于double类型，setprecision(15) 参数最大有效值为15，超过15，数据就不保证可靠了。string->double
string str="1245683.141592653"; double num=atof(str.c_str()); printf("%0.9lf\n",num);八、char*
char* To FString
FString MyFString = FString(UTF8_TO_TCHAR(MyCharPtr));九、UE4_Json
JsonObjectTo FString
处理Json需要在.Build.cs中添加Json模块
PrivateDependencyModuleNames.AddRange( new string[] { "CoreUObject", "Engine", "Slate", "SlateCore", "Json", // ... add private dependencies that you statically link with here ... } );//Jdata转换为了JsonStr FString JsonStr; TSharedRef<TJsonWriter<>> Writer = TJsonWriterFactory<>::Create(&JsonStr); FJsonSerializer::Serialize(Jdata.ToSharedRef(), Writer);