Calendar在Calendar.add()之后返回错误毫秒

Question

final Date now = new Date();
Calendar c = Calendar.getInstance();
final Calendar cal = Calendar.getInstance();
cal.setTime(now); 
cal.add(Calendar.HOUR_OF_DAY, 3); 
SetTime(c.getTimeInMillis());  

getTimeInMillis返回的时间与我拥有它的时间相同。非+3小时

如何正确地将小时数添加到当前时间？

Answer 1

您正在向另一个日历实例添加3个小时。

尝试：

final Date now = new Date();
final Calendar cal = Calendar.getInstance();
cal.setTime(now); 
cal.add(Calendar.HOUR_OF_DAY, 3); 
SetTime(cal.getTimeInMillis());  

正如Peter Lawrey和Brian Roach所说，没有必要创建Date对象。所以你可以这样做：

final Calendar cal = Calendar.getInstance();
cal.add(Calendar.HOUR_OF_DAY, 3); 
SetTime(cal.getTimeInMillis());