標(biāo)準(zhǔn)時(shí)間即(2017-05-05 17:33:09)字符串；

//時(shí)間戳 轉(zhuǎn) 標(biāo)準(zhǔn)時(shí)間（2017-07-15格式） - wsx注釋
+(NSString *)timeStampSwitchStandardTime:(long long)timeStamp{
    NSDate *date = [NSDate dateWithTimeIntervalSince1970:timeStamp];//秒數(shù)@"1493976789"轉(zhuǎn)時(shí)間    
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];
    NSString *time = [formatter stringFromDate:date];//時(shí)間轉(zhuǎn)標(biāo)準(zhǔn)時(shí)間字符串
    NSLog(@"標(biāo)準(zhǔn)時(shí)間字符串:%@",time);
    
    return time;
}

打印截圖：

秒轉(zhuǎn)標(biāo)準(zhǔn)時(shí)間.png

進(jìn)階轉(zhuǎn)換，顯示多少秒/分/小時(shí)/天之前，代碼如下:

//時(shí)間戳 轉(zhuǎn) 標(biāo)準(zhǔn)時(shí)間（2017-07-15格式） - wsx注釋
+(NSString *)timeStampSwitchStandardTime:(long long)timeStamp{
    NSDate *nowDate = [NSDate date];
    NSDate *oldDate = [NSDate dateWithTimeIntervalSince1970:timeStamp];//時(shí)間戳轉(zhuǎn)Date時(shí)間
    // 兩個(gè)時(shí)間戳的間隔   返回的是秒
    NSTimeInterval timeInterval = [nowDate timeIntervalSinceDate:oldDate];
    NSInteger interval = (NSInteger)timeInterval;
    //日期獲取 - wsx注釋
    NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"YYYY-MM-dd"];
    NSString *time;
    if (interval < 60 ) {
        time = [NSString stringWithFormat:@"%ld秒前",(long)interval];
    }else if (interval < 60*60){
        time = [NSString stringWithFormat:@"%ld分前",(long)interval/60];
    }else if (interval < 60*60*24){
        time = [NSString stringWithFormat:@"%ld小時(shí)前",(long)interval/3600];
    }else if (interval < 60*60*24*2){
        time = @"昨天";
    }else if (interval < 60*60*24*3){
        time = @"前天";
    }else{
        time = [formatter stringFromDate:oldDate];//時(shí)間轉(zhuǎn)標(biāo)準(zhǔn)時(shí)間字符串
    }
    NSLog(@"標(biāo)準(zhǔn)時(shí)間字符串:%@",time);
    
    return time;
}

標(biāo)準(zhǔn)時(shí)間轉(zhuǎn)時(shí)間戳：

- (NSString *)obtainTimeStampFromStandardTimeWithStartTime:(NSString *)startTime EndTime:(NSString *)endTime {
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateStyle:NSDateFormatterMediumStyle];
    [dateFormatter setTimeStyle:NSDateFormatterShortStyle];
    [dateFormatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"]; // hh表示:12小時(shí)制,HH表示:24小時(shí)制
    //設(shè)置時(shí)區(qū),這個(gè)對(duì)于時(shí)間的處理很重要
    NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:@"Asia/Shanghai"];
    [dateFormatter setTimeZone:timeZone];
    NSString *nowTimeStamp = [NSString stringWithFormat:@"%ld", (long)[[NSDate date] timeIntervalSince1970]];
    // 開(kāi)始時(shí)間轉(zhuǎn)換
    NSDate *startDate = [dateFormatter dateFromString:startTime]; // 將standardTime字符串按dateFormatter轉(zhuǎn)成NSDate
    NSString *startTimeStamp = [NSString stringWithFormat:@"%ld", (long)[startDate timeIntervalSince1970]]; // date與當(dāng)前時(shí)間差8小時(shí)  // 得到秒
    // 結(jié)束時(shí)間轉(zhuǎn)換
    NSDate *endDate = [dateFormatter dateFromString:endTime];
    NSString *endTimeStamp = [NSString stringWithFormat:@"%ld", (long)[endDate timeIntervalSince1970]]; // 得到秒
    // 比較時(shí)間差
    if ([[NSDate date] timeIntervalSinceDate:startDate] < 0.0f) {
        return @"未開(kāi)始";
    } else if ([[NSDate date] timeIntervalSinceDate:endDate] > 0.0f) {
        return @"已結(jié)束";
    }
    
    return @"進(jìn)行中";
}