IOS 中给数据排序的两种方法---持续更新中---

// 方法一  比 方法二 快 10倍以上，分别为大概0.000010 、0.000110左右

// 但是  方法二 更节省代码， 所以我还是采用方法 二

//    float themaxBloodSugar; // 最大值//    float theminBloodSugar; // 最小值    float thesumBloodSugar; // 平均值//    float themaxWeight;     // 最大值 weight//    float theminWeight;     // 最小值 weight    float thesunWeight;     // 平均值 weight    tb_History *maxHistory = (tb_History *)[historys objectAtIndex:0];                     tb_History *minHistory = (tb_History *)[historys objectAtIndex:0];    tb_History *maxWeightHistory = (tb_History *)[historys objectAtIndex:0];                     tb_History *minWeightHistory = (tb_History *)[historys objectAtIndex:0];    tb_History *lastHistory = (tb_History *)[historys objectAtIndex:0];    //    tb_History *tmpHistory = (tb_History *)[historys objectAtIndex:0];//    themaxBloodSugar = [tmpHistory.BloodSugar floatValue];//    theminBloodSugar = [tmpHistory.BloodSugar floatValue];//    thesumBloodSugar = [tmpHistory.BloodSugar floatValue];//    themaxWeight = [tmpHistory.Weight floatValue];//    theminWeight = [tmpHistory.Weight floatValue];//    thesunWeight = [tmpHistory.Weight floatValue];//    //    //方法一：//    //    NSDate *date1 = [NSDate date];//    //    //最大值、最小值、平均值//    //weight 最大值、最小值、平均值//    for (int i = 1; i < recycleCount; ++i) {//        tb_History *thetmpHistory = (tb_History *)[historys objectAtIndex:i];//        //        //bloodSugar//        if (thetmpHistory.BloodSugar.floatValue - themaxBloodSugar > 0.000001)//        {//            maxHistory = thetmpHistory;//            themaxBloodSugar = thetmpHistory.BloodSugar.floatValue;//        }//        if (theminBloodSugar - thetmpHistory.BloodSugar.floatValue >0.000001) {//            minHistory = thetmpHistory;//            theminBloodSugar = thetmpHistory.BloodSugar.floatValue;//        }//        thesumBloodSugar += thetmpHistory.BloodSugar.floatValue;//        //        //weight//        if (thetmpHistory.Weight.floatValue - themaxWeight > 0.000001)//        {//            maxWeightHistory = thetmpHistory;//            themaxWeight = thetmpHistory.Weight.floatValue;//        }//        if (theminWeight - thetmpHistory.Weight.floatValue >0.000001) {//            minWeightHistory = thetmpHistory;//            theminWeight = thetmpHistory.Weight.floatValue;//        }//        thesunWeight += thetmpHistory.Weight.floatValue;//    }//    //    NSDate *date2 = [NSDate date];//    NSLog(@"%f",[date2 timeIntervalSinceDate:date1]);        // 方法二：        NSDate *date1 = [NSDate date];        NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc]initWithKey:@"BloodSugar" ascending:NO];    [historys sortUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];        maxHistory = [historys objectAtIndex:0];    minHistory = [historys objectAtIndex:historys.count - 1];    for (tb_History *oneHistory in historys) {        thesumBloodSugar += oneHistory.BloodSugar.floatValue;        thesunWeight += oneHistory.Weight.floatValue;    }    [sortDescriptor release];        NSSortDescriptor *sortWeightDescriptor = [[NSSortDescriptor alloc]initWithKey:@"Weight" ascending:NO];    [historys sortUsingDescriptors:[NSArray arrayWithObject:sortWeightDescriptor]];        maxWeightHistory = [historys objectAtIndex:0];    minWeightHistory = [historys objectAtIndex:historys.count - 1];        [sortWeightDescriptor release];        NSDate *date2 = [NSDate date];    NSLog(@"%f",[date2 timeIntervalSinceDate:date1]);