Android - 无法从 AlertDialog 中显示 DatePicker

Question

我有一个 AlertDialog，其中包含一个用于启动 DatePicker 的按钮。是否可以在对话中完成此操作，如果可以，我将如何去做？

我已经搜索过 Google 和一些关于 SO 的帖子，但一直无法找到有关在 Alert Dialog 中完成 DatePicker 的信息。

Answer 1

没有看到你的代码，很难猜出错误在哪里，但你可以尝试下面的代码:

   public class MainActivity extends ActionBarActivity implements DatePickerDialog.OnDateSetListener {


    Context mContext;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //Set your Alert Dialog box code
        mContext=this;

        AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
        builder.setMessage("This is Alert dialog messgae")
        .setTitle("Launch the date Picker")
        .setPositiveButton("Date Pick", new OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                //Launch a date picker from Here
                showDatePickerDialog();

            }
        })
        .setNegativeButton("cancel", new OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
            //Cancel the Dialog itself  

            }
        });

        AlertDialog dialog = builder.create();
        dialog.show();

    }


    public void showDatePickerDialog() {
        DialogFragment newFragment = new DatePickerFragment();
        newFragment.show(getFragmentManager(), "datePicker");
    }

    private static class DatePickerFragment extends DialogFragment {

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            final Calendar c = Calendar.getInstance();
            int year = c.get(Calendar.YEAR);
            int month = c.get(Calendar.MONTH);
            int day = c.get(Calendar.DAY_OF_MONTH);

            // Create a new instance of DatePickerDialog and return it
            return new DatePickerDialog(getActivity(), (OnDateSetListener) getActivity(), year, month, day);
        }

    }

    @Override
    public void onDateSet(DatePicker view, int year, int monthOfYear,
            int dayOfMonth) {
        // TODO Auto-generated method stub

    }


}

如您所见，我在单击警报对话框按钮时使用 Fragment 创建了一个日期选择器。

你的Activity需要实现

onDateSet(DatePicker view, int year, int monthOfYear,int dayOfMonth)

否则应用程序会因 java.lang.ClassCastException 和以下错误消息而崩溃:

MainActivity$DatePickerFragment cannot be cast to android.app.DatePickerDialog$OnDateSetListener