Calendar.add（）后日历返回错误的毫秒数

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在我拥有它的同时返回。不是+3小时

如何正确添加当前时间？

Answer 1

您将3个小时添加到另一个日历实例。

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());