///获取日期
///参数year 1为1年以后的日期 -1为年之前的日期 0为今年
///参数month 1为1个月以后的日期 -1为一个月之前的日期 0为本月
///参数day 1为1天以后的日期 -1为一天之前的日期 0为今天
///返回日期的字符串
+(NSString*)getDate:(NSInteger)year month:(NSInteger)month day:(NSInteger)day
{
     NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
     NSDateComponents *comps = nil;
     comps = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:[NSDate date]];
     NSDateComponents *adcomps = [[NSDateComponents alloc] init];
     [adcomps setYear:year];
     [adcomps setMonth:month];
     [adcomps setDay:day];
     NSDate *newdate = [calendar dateByAddingComponents:adcomps toDate:[NSDate date] options:0];
     NSDateFormatter *formatter =  [[NSDateFormatter alloc] init];
     [formatter setDateFormat:@"yyyy-MM-dd"];
     NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:@"Asia/beijing"];
     [formatter setTimeZone:timeZone];
     NSString *dateFromData = [formatter stringFromDate:newdate];
 //    NSLog(@"dateFromData===%@",dateFromData);
     return dateFromData;
 }