Android：日期选择器侦听器从null到活动

Question

我在同一个活动中有两个日期选择器，它们相互连接，因为当用户更改一个日期时，另一个日期选择器日期会直接更改 以下是听众

  //initialize period date picker with current date and on date change listener 
        periodDatePicker.init(currentYear, currentMonth, currentDay, new OnDateChangedListener()
        {
            @Override
            public void onDateChanged(DatePicker periodDatePicker, int currentYear, int currentMonth,int currentDay) {
                // TODO Auto-generated method stub
                Number = 1;
            birthDayDatePicker.init(currentYear, currentMonth, currentDay, null);
                birthDateCalculations();

            }
        });

        //initialize birth date picker with current date and on date change listener 
        birthDayDatePicker.init(currentYear, currentMonth, currentDay, new OnDateChangedListener () {

            @Override
            public void onDateChanged(DatePicker birthDayDatePicker, int currentYear, int currentMonth, int currentDay) {
                // TODO Auto-generated method stub
                Number = 2;
                periodDatePicker.init(currentYear, currentMonth, currentDay, null);
                periodDateCalculations();               
            }
        });

当调用一个日期选择器侦听器时，我将另一个侦听器转到第二个日期选择器为null，我的问题是，如何使我转向null的侦听器再次激活< / em>

Answer 1

修改
如果为侦听器分配变量，则可以重用它们。你似乎也有变量名冲突。调用OnDateChangedListener时，会有currentYear/currentMonth/currentDay个函数参数和类成员变量：

OnDateChangedListener periodListener = null;
OnDateChangedListener birthdayListener  = null;

periodListener = new OnDateChangedListener() {
         @Override
         public void onDateChanged(DatePicker periodDatePicker, int newYear, int newMonth, int newDay) {
              Number = 1;
              birthDayDatePicker.init(currentYear, currentMonth, currentDay, null);
              birthDateCalculations();
              birthDayDatePicker.init(currentYear, currentMonth, currentDay, birthdayListener);
         }


birthdayListener = new OnDateChangedListener () {    
         @Override
         public void onDateChanged(DatePicker birthDayDatePicker, int newYear, int newMonth, int newDay) {
              Number = 2;
              periodDatePicker.init(currentYear, currentMonth, currentDay, null);
              periodDateCalculations();               
              periodDatePicker.init(currentYear, currentMonth, currentDay, periodListener);
         }
    });


birthDayDatePicker.init(currentYear, currentMonth, currentDay, birthdayListener);
periodDatePicker.init(currentYear, currentMonth, currentDay, periodListener);

Answer 2

在类级别创建侦听器，只需在代码中使用它。 癌症的答案是正确的。