UE4笔记-http请求带中文字符串的使用问题记录(encodeURI/UriEncode)

类似JavaScript 的 encodeURI功能...

UE4使用IHttpRequest请求时 当Uri 路径中带中文字符时，需要进行百分比编码，否则无法正确解析Url路径和参数:

FString temp = FGenericPlatformHttp::UrlEncode(queryStr);
FString uri = FString::Printf(TEXT("http://www.yoursite.com?QueryString=%s"),*temp);

Note:

截至UE4.23,FGenericPlatformHttp::UrlEncode 函数不能解析整条http url.（因为UE4不会忽略’:‘，'/'，'@'以及'#' 等字符串）

如果需要整条字符串一起处理，可以考虑自己复制扩展或修改一下源码：

源码：

GenericPlatformHttp.cpp中修改AllowedChars 字符串 添加 ‘#’，‘/’，‘:’,'@'等符号进行忽略.

或直接复制扩展,如:

static bool IsAllowedChar(UTF8CHAR LookupChar)
{
    static char AllowedChars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-+=_.~:/#@?&";
    static bool bTableFilled = false;
    static bool AllowedTable[256] = { false };

    if (!bTableFilled)
    {
        for (int32 Idx = 0; Idx < ARRAY_COUNT(AllowedChars) - 1; ++Idx)    // -1 to avoid trailing 0
        {
            uint8 AllowedCharIdx = static_cast<uint8>(AllowedChars[Idx]);
            check(AllowedCharIdx < ARRAY_COUNT(AllowedTable));
            AllowedTable[AllowedCharIdx] = true;
        }

        bTableFilled = true;
    }

    return AllowedTable[LookupChar];
}

FString UCoreBPLibrary::UrlEncode( const FString &UnencodedString)
{
    FTCHARToUTF8 Converter(*UnencodedString);    //url encoding must be encoded over each utf-8 byte
    const UTF8CHAR* UTF8Data = (UTF8CHAR*)Converter.Get();    //converter uses ANSI instead of UTF8CHAR - not sure why - but other code seems to just do this cast. In this case it really doesn't matter
    FString EncodedString = TEXT("");

    TCHAR Buffer[2] = { 0, 0 };

    for (int32 ByteIdx = 0, Length = Converter.Length(); ByteIdx < Length; ++ByteIdx)
    {
        UTF8CHAR ByteToEncode = UTF8Data[ByteIdx];

        if (IsAllowedChar(ByteToEncode))
        {
            Buffer[0] = ByteToEncode;
            FString TmpString = Buffer;
            EncodedString += TmpString;
        }
        else if (ByteToEncode != '')
        {
            EncodedString += TEXT("%");
            EncodedString += FString::Printf(TEXT("%.2X"), ByteToEncode);
        }
    }
    return EncodedString;
}