1.
char boxData[100];
fi.mWidth = 1.0, fi.mCenter_x= 2.1, fi.mCenter_y=1.1;
sprintf(boxData, ",mWidth:%f,mCenter_x:%f,mCenter_y,:%f}", fi.mWidth, fi.mCenter_x, fi.mCenter_y);
//boxData = "mWidth:1.00000000,mCenter_x:2.10000000,mCenter_y,:1.100000000";
原文：https://www.cnblogs.com/indifferent/p/11880386.html