星期几的Android日历问题

Question

我正在尝试列出本周一至周日的一周中的所有天。例如，今天（发布日期）为2011年9月4日，即星期日。

我正在启动日历并将一周的第一天设置为星期一：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);

当我检查每月的某天时，会得到正确的结果：

int check = cal.get(Calendar.DAY_OF_MONTH);
// check is equal to 4

但是，当我将工作日设置为星期一时，它将跳至下一周而不是返回本周的星期一：

cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
// mon is equal to 5, when expected to be 29 (last Monday of August)

甚至将工作日设置为星期日也将在下个星期日而不是今天返回。

有人可以解释为什么这样做会如此，什么是解决此问题的最佳方法？

Answer 1

实际上，当我检查自己的测试时，它似乎可以正常工作， 除非没有再次设置日期 ：

显示4-29 ：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);
cal.set(2011, 8, 4);
int test = cal.get(Calendar.DAY_OF_MONTH);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
bTest.setText("" + test + "-" + mon);

显示5-5 ：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);
cal.set(2011, 8, 5);
int test = cal.get(Calendar.DAY_OF_MONTH);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
bTest.setText("" + test + "-" + mon);

显示14-12 ：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);
cal.set(2011, 8, 14);
int test = cal.get(Calendar.DAY_OF_MONTH);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
bTest.setText("" + test + "-" + mon);

因此，这不起作用：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);
//cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH));
int test = cal.get(Calendar.DAY_OF_MONTH);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
bTest.setText("" + test + "-" + mon); // Display 4-5

而 这个工程 ：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);

// Workaround
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH));

int test = cal.get(Calendar.DAY_OF_MONTH);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
bTest.setText("" + test + "-" + mon); // Display 4-29

而 这个工程 太：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);

// Workaround
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH));
cal.get(Calendar.DAY_OF_MONTH);

cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
bTest.setText("" + mon); // Display 29

但这不是：

Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);

// Workaround
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH));
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
int mon = cal.get(Calendar.DAY_OF_MONTH);
bTest.setText("" + mon); // Display 5