开发中关于日期的处理：NSDate中取出日期、取出时间等

有时候开发中我们只需要年月日、或者只需要时分秒，刚开始由于对NSDate不是很熟悉，走了很多弯路，特在此记录！！回头要好好把NSDate的文档好好看看

  NSDate *date = _datePickerView.date;
    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
    // Get Current  Hour
    [formatter setTimeStyle:NSDateFormatterShortStyle];
    NSLog(@"test------ %@",[formatter stringFromDate:date]);
<pre name="code" class="objc">//这样设置得到的格式是这样的： test------ 下午2:19

    [formatter setDateStyle:NSDateFormatterShortStyle];
    NSLog(@"test+_+++++++ %@",[formatter stringFromDate:date]);

//test+_+++++++ 14-8-12 下午2:19

[formatter setDateStyle:NSDateFormatterShortStyle];

[formatter setTimeStyle:NSDateFormatterNoStyle];

NSLog(@"test+_+++++++ %@",[formatter stringFromDate:date]);

//test+_+++++++ 14-8-12

由上面可以知道，我们可以通过设置 setDateStyle 和setTimeStyle的格式来分别得到我们想要的结果：日期、时间等

如果我们想获取年、或者月、或者日、或者小时、或者分钟等单个值时该如何做呢？看代码如下：

    NSDate *date = [NSDate date];

    // Get Current Year

    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
    [formatter setDateFormat:@"yyyy"];

    NSString *currentyearString = [NSString stringWithFormat:@"%@",
                    [formatter stringFromDate:date]];

    // Get Current  Month

    [formatter setDateFormat:@"MM"];

    currentMonthString = [NSString stringWithFormat:@"%d",[[formatter stringFromDate:date]integerValue]];

    // Get Current  Date

    [formatter setDateFormat:@"dd"];
    NSString *currentDateString = [NSString stringWithFormat:@"%@",[formatter stringFromDate:date]];

    // Get Current  Hour
    [formatter setDateFormat:@"hh"];
    NSString *currentHourString = [NSString stringWithFormat:@"%@",[formatter stringFromDate:date]];

    // Get Current  Minutes
    [formatter setDateFormat:@"mm"];
    NSString *currentMinutesString = [NSString stringWithFormat:@"%@",[formatter stringFromDate:date]];

    // Get Current  AM PM

    [formatter setDateFormat:@"a"];
    NSString *currentTimeAMPMString = [NSString stringWithFormat:@"%@",[formatter stringFromDate:date]];

开发中关于日期的处理：NSDate中取出日期、取出时间等