c++ sprintf() 用法

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";