iphone - NSDate 来自字符串

Question

我有一个字符串“2012-09-16 23:59:59 JST”我想将此日期字符串转换为 NSDate。

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd hh:mm:ss Z"];
NSDate *capturedStartDate = [dateFormatter dateFromString: @"2012-09-16 23:59:59 JST"];
NSLog(@"%@", capturedStartDate);

但它不起作用。它给出空值。请帮忙..

Answer 1

使用 24 小时制时，小时说明符必须是大写 H，如下所示：

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

在此处检查正确的说明符：http ://unicode.org/reports/tr35/tr35-6.html#Date_Format_Patterns

但是，您需要为日期格式化程序设置语言环境：

// Set the locale as needed in the formatter (this example uses Japanese)
[dateFormat setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"ja_JP"]];

完整的工作代码：

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss zzz"];
[dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"ja_JP"]];
NSDate *capturedStartDate = [dateFormatter dateFromString: @"2012-09-16 23:59:59 JST"];
NSLog(@"Captured Date %@", [capturedStartDate description]);

输出（格林威治标准时间）：

Captured Date 2012-09-16 14:59:59 +0000

Answer 2

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss Z"];
NSDate *capturedStartDate = [dateFormatter dateFromString: @"2012-09-16 23:59:59 GMT-08:00"];
NSLog(@"%@", capturedStartDate);

Answer 3

NSString *dateString = @"01-02-2010";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

// this is imporant - we set our input date format to match our input string
// if format doesn't match you'll get nil from your string, so be careful

[dateFormatter setDateFormat:@"dd-MM-yyyy"];
NSDate *dateFromString = [[NSDate alloc] init];
 // end
dateFromString = [dateFormatter dateFromString:dateString];
[dateFormatter release];