关于Label更换内容的问题（调用的xml）

Cocos2d-x
#1

头文件含有如下代码：
std::string mlabel;
int x=0;
LabelTTF* m_label;

INIT里面有如下代码 char *cstring;
std::string name;
__String *ns;

CCDictionary *strings = CCDictionary::createWithContentsOfFile("disanguan.xml");


for (int i = 0; i < 24; ++i)
{
    ns = __String::createWithFormat("%d", i + 1);
    cstring = ns->getCString();
    name = cstring;
    mlabel* = ((CCString*)strings->objectForKey(name))->getCString();
}

m_label = LabelTTF::create(mlabel, "Arial", 40);
m_label->setPosition(Vec2(160, 200));
this->addChild(m_label);

接下来是鼠标点击的代码，为什么会报错呢！说不能把TTF转换成const std::string？？？？？？
bool HelloWorld::onTouchBegan(Touch *touch, Event *unused_event)
{

Point location = touch->getLocation();

auto spr = (Sprite*)this->getChildByTag(1);
Rect rect = spr->getBoundingBox();

if (rect.containsPoint(location))
{
    
    m_label->setString(us);
}
else
    CCLOG("NO!NO!NO!NO!NO!NO!NO!");
return true;

}*

#2

求解答喵~~~