#import <Foundation/Foundation.h>@interface NSDate (MJ)/** *  是否为今天 */- (BOOL)isToday;/** *  是否为昨天 */- (BOOL)isYesterday;/** *  是否为今年 */- (BOOL)isThisYear;/** *  返回一个只有年月日的时间 */- (NSDate *)dateWithYMD;/** *  获得与当前时间的差距 */- (NSDateComponents *)deltaWithNow;@end

////  NSDate+MJ.m//  ItcastWeibo////  Created by apple on 14-5-9.//  Copyright (c) 2014年 itcast. All rights reserved.//#import "NSDate+MJ.h"@implementation NSDate (MJ)/** *  是否为今天 */- (BOOL)isToday{    NSCalendar *calendar = [NSCalendar currentCalendar];    int unit = NSCalendarUnitDay | NSCalendarUnitMonth |  NSCalendarUnitYear;        // 1.获得当前时间的年月日    NSDateComponents *nowCmps = [calendar components:unit fromDate:[NSDate date]];        // 2.获得self的年月日    NSDateComponents *selfCmps = [calendar components:unit fromDate:self];    return    (selfCmps.year == nowCmps.year) &&    (selfCmps.month == nowCmps.month) &&    (selfCmps.day == nowCmps.day);}/** *  是否为昨天 */- (BOOL)isYesterday{    // 2014-05-01    NSDate *nowDate = [[NSDate date] dateWithYMD];        // 2014-04-30    NSDate *selfDate = [self dateWithYMD];        // 获得nowDate和selfDate的差距    NSCalendar *calendar = [NSCalendar currentCalendar];    NSDateComponents *cmps = [calendar components:NSCalendarUnitDay fromDate:selfDate toDate:nowDate options:0];    return cmps.day == 1;}- (NSDate *)dateWithYMD{    NSDateFormatter *fmt = [[NSDateFormatter alloc] init];    fmt.dateFormat = @"yyyy-MM-dd";    NSString *selfStr = [fmt stringFromDate:self];    return [fmt dateFromString:selfStr];}/** *  是否为今年 */- (BOOL)isThisYear{    NSCalendar *calendar = [NSCalendar currentCalendar];    int unit = NSCalendarUnitYear;        // 1.获得当前时间的年月日    NSDateComponents *nowCmps = [calendar components:unit fromDate:[NSDate date]];        // 2.获得self的年月日    NSDateComponents *selfCmps = [calendar components:unit fromDate:self];        return nowCmps.year == selfCmps.year;}- (NSDateComponents *)deltaWithNow{    NSCalendar *calendar = [NSCalendar currentCalendar];    int unit = NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;    return [calendar components:unit fromDate:self toDate:[NSDate date] options:0];}@end

// 创建格式化类    NSDateFormatter *fmt = [[NSDateFormatter alloc] init];    // 设置格式      _created_at = @"Mon Jul 14 16:13:07 +0800 2014";    fmt.dateFormat = @"EEE MMM dd HH:mm:ss Z yyyy";    #warning 真机调试(真机显示时间，要写上这句话)    fmt.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];    // 获得发微博的具体时间    NSDate *createDate = [fmt dateFromString:_created_at];        // 判断是否为今年    if (!createDate.isThisYear) {        fmt.dateFormat = @"yyyy-MM-dd";        return [fmt stringFromDate:createDate];    }        if (!createDate.isToday && !createDate.isYesterday) { // 不是今天，也不是昨天            fmt.dateFormat = @"MM-dd HH:mm";            return [fmt stringFromDate:createDate];    }    if (!createDate.isToday) {        fmt.dateFormat = @"昨天 HH:mm";        return [fmt stringFromDate:createDate];    }    NSDateComponents *cmps = [createDate deltaWithNow];        if (!cmps.hour >= 1 && !cmps.minute >= 1) {         return @"刚刚";    }        if (!cmps.hour >= 1) {        return [NSString stringWithFormat:@"%d分钟前", cmps.minute];    }        return  [NSString stringWithFormat:@"%d小时前", cmps.hour];