先乘取整再除

float fScore;
fScore=0.123456;
//*100表示保留的精度為0.01
//+0.005是為了四捨五入
int u32Score = (fScore+0.005) * 100;
fScore = (float)u32Score / 100;

字串法

/** 計算浮點型四捨五入。*/
float BaseConstruction::getAccuracy(float input,unsigned int accuracy)
{
#define buf_size 100
    //通過輸入生成精度字串 （%0.*f）
    char accuracyBuf[buf_size];
    sprintf_s(accuracyBuf,buf_size,"%%0.%df",accuracy);

    //通過輸入生成對應精度的float形列印輸出
    char outputBuf[buf_size];
    sprintf_s(outputBuf,buf_size,accuracyBuf,input);

    //迴轉回float行資料
    float output = atof(outputBuf);
    return output;
}
 

參考：

1.https://www.cnblogs.com/Again/p/6406848.html