较复杂的日期时间处理

1、如何如何将一个字符串如“ 20110826134106”装化为任意的日期时间格式，下面列举两种类型：
NSString* string = @"20110826134106";
NSDateFormatter *inputFormatter = [[[NSDateFormatter alloc] init] autorelease];
[inputFormatter setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"] autorelease]];
[inputFormatter setDateFormat:@"yyyyMMddHHmmss"];
NSDate* inputDate = [inputFormatter dateFromString:string];
NSLog(@"date = %@", inputDate);

NSDateFormatter *outputFormatter = [[[NSDateFormatter alloc] init] autorelease]; 
[outputFormatter setLocale:[NSLocale currentLocale]];
[outputFormatter setDateFormat:@"yyyy年MM月dd日 HH时mm分ss秒"];
NSString *str = [outputFormatter stringFromDate:inputDate];
NSLog(@"testDate:%@", str);
两次打印的结果为：
date = 2011-08-26 05:41:06 +0000
testDate:2011年08月26日 13时41分06秒
/*

NSDateFormatter *dateFormatter=[[NSDateFormatteralloc]init];
[dateFormatter setDateFormat:@"yyyy"];
NSString *Str=[dateFormatter stringFromDate:[NSDate date]];
[dateFormatter release];
NSDateFormatter *dateFormatter1=[[NSDateFormatteralloc]init];
[dateFormatter1 setDateFormat:@"MM"];
NSString *Str1=[dateFormatter1 stringFromDate:[NSDate date]];
[dateFormatter1 release];
NSDateFormatter *dateFormatter2=[[NSDateFormatteralloc]init];
[dateFormatter2 setDateFormat:@"dd"];
NSString *Str3=[dateFormatter2 stringFromDate:[NSDate date]];

[dateFormatter2 release];
NSString *dateStr=[NSStringstringWithFormat:@"%@-%@-%@ 00:00:00",Str,Str1,Str3];
NSLog(@"dateStr------------%@",dateStr);
//将传入时间转换成需要的格式
NSDateFormatter *format=[[NSDateFormatteralloc]init];
//[dateFormatter setLocale:[[NSLocale alloc]initWithLocaleIdentifier:@"zh_CN"]];//location设置为中国

// [format setLocale:[[NSLocale alloc]initWithLocaleIdentifier:@"zh_CN"]];//location设置为中国
[format setLocale:[NSLocalecurrentLocale]];

[format setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *inputDate=[[format dateFromString:dateStr] retain];
NSTimeZone *fromzone = [NSTimeZonesystemTimeZone];
NSInteger frominterval = [fromzonesecondsFromGMTForDate: inputDate];
fromDate = [[inputDate dateByAddingTimeInterval: frominterval] retain];

NSLog(@"fromDate------zh---------%@",fromDate);

- (id)initWithFrame:(CGRect)frame {
if ((self = [super initWithFrame:frame])) {
//默认日期格式为yyyy-MM-dd
dateFormatter= [[NSDateFormatter alloc] init];
[dateFormatter setLocale:[[NSLocale alloc]initWithLocaleIdentifier:@"zh_CN"]];//location设置为中国
[dateFormatter setDateFormat:@"yyyy-MM-dd"];
//picker的默认时间为当前时间
date=[NSDate date];
//picker的默认style为只显示日期
datePickerMode=UIDatePickerModeDate;

//构造一个子视图,用于显示日期选择器
subview=[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)];
subview.backgroundColor=[UIColor clearColor];
subview.tag=0;

*/

说明：上面的时间是美国时间，下面的没有设置

NSString* string = @"Wed, 05 May 2011 10:50:00 +0800";
NSDateFormatter *inputFormatter = [[[NSDateFormatter alloc] init] autorelease];
[inputFormatter setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"] autorelease]];
[inputFormatter setDateFormat:@"EEE, d MMM yyyy HH:mm:ss Z"];
NSDate* inputDate = [inputFormatter dateFromString:string];
NSLog(@"date = %@", inputDate);

// 获得本地时间指定时区
NSDate *dates = [NSDate date];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:@"Asia/beijing"];
[formatter setTimeZone:timeZone];
NSString *loctime = [formatter stringFromDate:dates];