How to set language of Bing Map for QGC iOS build

Hello, I’m a newbie Qt developer for building QGC source code.

I’ve deployed QGC app to iPad successfully, but found the language of Bing Map is English. I trace QGC source code and got the map download function code in “QGCMapUrlEngine.cpp”:

UrlFactory::_getURL()
{

case BingHybrid:
{

return QString(“http://ecn.t%1.tiles.virtualearth.net/tiles/h%2.jpeg?g=%3&mkt=%4”).arg(getServerNum(x, y, 4)).arg(key).arg(versionBingMaps).arg(_language);
}

}

While QGC running on iPad, the default value of “_language” is “zh-Hant-TW”, and the Bing Map download url is like: "http://ecn.t2.tiles.virtualearth.net/tiles/h13212312220122322.jpeg?g=563&mkt=zh-Hant-TW”, but the name of road is English.

I want to show road name in Chinese, and try to modify the parameter “mkt” of url to “zh-TW” or “zh-Hant”, but it’s not work. The road name in map is still in English.

Sorry for my poor English. If someone has any suggestions for me to set the language of Bing Map, please let me know, I’m very appreciate for your help.