[游戏开发]【UE4】如何区分中英文字符

在ue4 FString字符串中如何判断每一个字符是中文还是英文？思路是将FString中每一个TCHAR转成UTF8，根据UTF8的长度判断是中文还是英文，中文的长度是3，英文的长度是1。主要用到了UE4封装的FTCHARToUTF8。具体代码如下：

FString somestring; //只包含中英字符
int cnt = 0;
while(cnt <= somestring.Len())
{
	//第一个参数：取FString的第cnt个字符的地址
	//第二个参数：转换长度为1，如果没有这个长度参数则转换第cnt个字符开始FString所有剩下的参数
	FTCHARToUTF8 sometchar_utf8(&somestring[cnt],1);
	if(sometchar_utf8.Length() == 3)
		//中文
	else //sometchar_utf8.Length() == 1
		//英文
	cnt++;
}

知识要点：
1、UTF8编码方式
2、UE4源码StringConv.h，截取相关性大的一些源码:

//...省略
typedef TStringConversion<FTCHARToUTF8_Convert> FTCHARToUTF8;
//...省略
template<typename Converter, int32 DefaultConversionSize = DEFAULT_STRING_CONVERSION_SIZE>
class TStringConversion : private Converter, private TInlineAllocator<DefaultConversionSize>::template ForElementType<typename Converter::ToType>
{
	typedef typename TInlineAllocator<DefaultConversionSize>::template ForElementType<typename Converter::ToType> AllocatorType;

	typedef typename Converter::FromType FromType;
	typedef typename Converter::ToType   ToType;

	/**
	 * Converts the data by using the Convert() method on the base class
	 */
	void Init(const FromType* Source, int32 SourceLen, ENullTerminatedString::Type NullTerminated)
	{
		StringLength = Converter::ConvertedLength(Source, SourceLen);
		int32 BufferSize = StringLength + NullTerminated;
		AllocatorType::ResizeAllocation(0, BufferSize, sizeof(ToType));
		Ptr = (ToType*)AllocatorType::GetAllocation();
		Converter::Convert(Ptr, BufferSize, Source, SourceLen + NullTerminated);
	}
public:
	//...省略
	TStringConversion(const FromType* Source, int32 SourceLen)
	{
		if (Source)
		{
			ENullTerminatedString::Type NullTerminated = ENullTerminatedString::No;
			if (SourceLen > 0 && Source[SourceLen-1] == 0)
			{
				// Given buffer is null-terminated
				NullTerminated = ENullTerminatedString::Yes;
				SourceLen -= 1;
			}
			Init(Source, SourceLen, NullTerminated);
		}
		else
		{
			Ptr = nullptr;
			StringLength = 0;
		}
	}
	//...省略
	/**
	 * Length of the converted string.
	 *
	 * @return The number of characters in the converted string, excluding any null terminator.
	 */
	FORCEINLINE int32 Length() const
	{
		return StringLength;
	}

private:
	// Non-copyable
	TStringConversion(const TStringConversion&) = delete;
	TStringConversion& operator=(const TStringConversion&) = delete;
	ToType* Ptr;
	int32   StringLength;
};