Question

获取了原始的TimePicker-Source

并将其粘贴到Android Studio中的新类中。 Android Studio会抛出错误“修改程序'静态'，此处不允许”。怎么了？这是来源：

public static class TimePickerFragment extends DialogFragment
                        implements TimePickerDialog.OnTimeSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current time as the default values for the picker
        final Calendar c = Calendar.getInstance();
        int hour = c.get(Calendar.HOUR_OF_DAY);
        int minute = c.get(Calendar.MINUTE);

        // Create a new instance of TimePickerDialog and return it
        return new TimePickerDialog(getActivity(), this, hour, minute,
                DateFormat.is24HourFormat(getActivity()));
    }

    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
        // Do something with the time chosen by the user
    }
}

顺便说一下：有没有一种简单的方法可以在活动中使用时间戳？这里几乎所有的例子都使用“showDialog（）”，这是一个被删除的。

Answer 1

提供的示例隐式假设您将该代码添加到另一个Activity或Fragment内部作为内部类。如果那不是您正在做的事情，请从中删除static。请注意，DialogFragment之间在外部类中进行通信时会有点烦人（您必须使用接口来回通信）。

关于第二个问题，要显示对话框，请使用以下内容：

DialogFragment dialog = new MyDialogFragment();
dialog.show(getFragmentManager(), "MyDialog");

Answer 2

您试图将上述内容与活动类减速并行粘贴，实际上上面的代码应该是内部类。

public class NewCaseEntry extends AppCompatActivity {}
public static class TimePickerFragment extends ... {}

这是错的，应该是

public class NewCaseEntry extends AppCompatActivity {
    public static class TimePickerFragment extends ... {}
}

Answer 3

首先，感谢Kasra！

我还发现，你必须将它放在一个对话框片段中。但这些来自API 11及更高版本（我的将支持API 5）。可以通过在Android Studio中安装兼容包来使用它们。所以我等待去除，可能在API 20我的应用已经过时了： - ）

Answer 4

它应该用作内部类，并带有 static 词，如下所示：

public class yourclassname extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate ( savedInstanceState );
    setContentView ( R.layout.activity_input );
}

public static class TimePickerFragment extends DialogFragment
        implements TimePickerDialog.OnTimeSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current time as the default values for the picker
        final Calendar c = Calendar.getInstance();
        int hour = c.get(Calendar.HOUR_OF_DAY);
        int minute = c.get(Calendar.MINUTE);

        // Create a new instance of TimePickerDialog and return it
        return new TimePickerDialog(getActivity(), this, hour, minute,
                DateFormat.is24HourFormat(getActivity()));
    }

    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
        // Do something with the time chosen by the user
    }
}

}

如果要将其作为单独的类，则可以使用它而无需使用 static 字词，如下所示：

public class TimePickerFragment extends DialogFragment
        implements TimePickerDialog.OnTimeSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current time as the default values for the picker
        final Calendar c = Calendar.getInstance();
        int hour = c.get(Calendar.HOUR_OF_DAY);
        int minute = c.get(Calendar.MINUTE);

        // Create a new instance of TimePickerDialog and return it
        return new TimePickerDialog(getActivity(), this, hour, minute,
                DateFormat.is24HourFormat(getActivity()));
    }

    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
        // Do something with the time chosen by the user
    }
}

Android开发人员的Timepicker不允许静态

4 个答案: