NSDate/NSData

NSDate/NSData中常用的方法

NSString
*str = @"1234abcd";

NSData
*data = [str
dataUsingEncoding:NSUTF8StringEncoding];//将字符转换成dataNSUTF8StringEncoding为编码格式

NSString
*str1 = [[NSString
alloc]
initWithData:data
encoding:NSUTF8StringEncoding];//将data转换成字符

NSLog(@"%@",str1);

NSLog(@"%@",data);

NSLog(@"%zi",data.length);//data的长度

NSData
*data1 = [NSData
dataWithContentsOfURL:[NSURL
URLWithString:@"http://image.baidu.com"]];//获取网络数据

//NSLog(@"%@",data1);

NSMutableData
*data2 = [NSMutableData
data];//创建一个空的数据
[data2
appendData:data];

//1.获取当前时间

NSDate
*date1 = [NSDate
date];

NSLog(@"1. %@",date1);

//2.以当前时间为基准n秒后的时间

NSDate
*date2 = [NSDate
dateWithTimeIntervalSinceNow:60];

NSLog(@"2. %@",date2);

//3.以1970年为基准n秒后的时间

NSDate
*date3 = [NSDate
dateWithTimeIntervalSince1970:24*60*60];

NSLog(@"3. %@",date3);

//4.
在某一时间上加过n秒后的时间

NSDate
*afterTime = [date1
dateByAddingTimeInterval:60];

NSLog(@"4. %@",afterTime);

//5.获取当前时间距离1970年的秒数

NSTimeInterval
time = [[NSDate
date]
timeIntervalSince1970];

NSLog(@"5. %lf",time);

NSTimeInterval
time1 = [[NSDate
dateWithTimeIntervalSinceNow:60]
timeIntervalSince1970];

NSLog(@"5. %lf",time1);

//6.
返回给定时间与当前时间的时间差单位秒

NSTimeInterval
time2 = [date1
timeIntervalSinceNow];

NSLog(@"6. %lf",time2);

NSTimeInterval
time3 = [date2
timeIntervalSinceNow];

NSLog(@"6. %lf",time3);

//7.获取两日期之间的时间差

NSTimeInterval
time4 = [date2
timeIntervalSinceDate:date1];

NSLog(@"7. %lf",time4);

//8.获取两个日期中距1970最远(最近)的日期

NSDate
*laterOne = [date1
laterDate:date2];

NSLog(@"8. %@",laterOne);

NSDate
*earlyOne= [date1
earlierDate:date2];

NSLog(@"8. %@",earlyOne);

//9.日期时间格式化对象

NSDateFormatter
*foma = [[NSDateFormatter
alloc]
init];
[foma
setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

NSDateFormatter
*dateFormatter = [NSDateFormatter
new];

[dateFormatter
setDateFormat:
@"yyyy年MM月dd日
HH:mm:ss"];

NSLog(@"9. %@",[dateFormatter
stringFromDate:date1]);

//10.把日期格式的字符串转换成日期对象

NSString
*myDateTimeStr =
@"2015.11.3 12:12:12";

NSDateFormatter
*formatter = [NSDateFormatter
new];

[formatter
setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

NSDate
*newDate = [formatter
dateFromString:myDateTimeStr];

NSLog(@"10. %@",[formatter
stringFromDate:newDate]);

//11.系统时区

NSTimeZone
*zone = [NSTimeZone
systemTimeZone];

NSLog(@"11. %@",zone);

//12.系统时区缩写

NSString
*str = [zone
abbreviation];

NSLog(@"12. %@",str);

//13.当地时区

NSTimeZone
*localTimeZone = [NSTimeZone
localTimeZone];

NSLog(@"13. %@",localTimeZone);

//14.和格林尼治时间差

NSInteger
timeOff = [zone
secondsFromGMT];

NSLog(@"14. %ld",(long)timeOff);

//15.时差转换

NSDate
*timeOffDate = [date1
dateByAddingTimeInterval:[[NSTimeZone
systemTimeZone]
secondsFromGMT]];

NSLog(@"15. %@",timeOffDate);

//时差转换

//1.

NSString
*str1 =
@"2015-11-11 11:11:11";

NSDate
*date1 = [NSDate
date];

NSDateFormatter
*formatter = [[NSDateFormatter
alloc]
init];

[formatter
setDateFormat:@"yyyy/MM/dd HH:mm:ss"];

NSDate
*newDate = [formatter
dateFromString:str1];

NSLog(@"%@",[formatter
stringFromDate:newDate]);

NSLog(@"%@",newDate);

//2.

NSDate
*d = [date1
dateByAddingTimeInterval:[[NSTimeZone
systemTimeZone]
secondsFromGMT]];

NSLog(@"%@",d);

//3.

NSDateFormatter
*fm = [[NSDateFormatter
alloc]
init];

[fm setTimeZone:[NSTimeZone
timeZoneForSecondsFromGMT:0]];

NSLog(@"%@",[fm
stringFromDate:[NSDate
date]]);