DatePicker.OnDateChangedListener 调用了两次 [英] DatePicker.OnDateChangedListener called twice
问题描述
我正在尝试创建一个应用程序,其中用户从 DatePicker 中选择一个日期,然后使用一些值更新列表.
I'm trying to create an app where the user selects a date from a DatePicker, and then a list is updated with some values.
我的 GUI 如下所示:
My GUI looks like this:
<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" >
<DatePicker
android:id="@+id/datePicker"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ListView
android:id="@+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
</ListView>
</LinearLayout>
而我的 DatePicker 初始化和处理如下所示:
Whereas my DatePicker initialization and handling look as follows:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
datePicker = (DatePicker) findViewById(R.id.datePicker);
Calendar c = Calendar.getInstance();
year = c.get(Calendar.YEAR);
month = c.get(Calendar.MONTH);
day = c.get(Calendar.DAY_OF_MONTH);
datePicker.init(year, month, day, dateSetListener);
}
private DatePicker.OnDateChangedListener dateSetListener = new DatePicker.OnDateChangedListener() {
public void onDateChanged(DatePicker view, int year, int monthOfYear,
int dayOfMonth) {
Calendar c = Calendar.getInstance();
c.set(year, monthOfYear, dayOfMonth);
System.out.println ("TEST");
}
};
在 CatLog 中,我看到TEST"字符串输出两次,每次我玩小部件上的 +/- 按钮时.可能是什么问题?
In CatLog I see that "TEST" string is output twice, each time I play with the +/- buttons on the widget. What could be the problem?
注意:我故意禁用"了列表更新代码,以确保问题与 ListView 无关,如 here
Note: I've "disabled" the list-updating code on purpose, in order to make sure that the problem is not related to the ListView, as in here
推荐答案
当我测试我的应用程序时,方法 onDateSet 在接受日期选择后调用了两次,在我取消时调用了一次.
When I test my application, method onDateSet called twice after accept the date selection and once when I canceled.
我在带有参数视图的 onDateSet 方法中添加了一个验证,类似这样
I added a validation in the method onDateSet with parameter view, something like this
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth){
if (view.isShown()) {
updateDate(year, monthOfYear, dayOfMonth);
}
}
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