Android 从声明为public void的方法中检索值

大家好，我是Android和Java新手，我正在编写一个日期选择器片段类，它扩展了DialogFragment，并实现了DatePickerDialog.OnDateSetListener，因此我必须声明方法

public void onDateSet（DatePicker视图，int year，int month，int day）

，在其中，我正在

公共
字符串
变量中设置新日期

是否可以在我的主要活动中使用此
公共字符串
变量在
文本视图
中显示值？如果是，怎么做

我的主要活动代码是：

public class TARForm extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener {

    EditText departuredate;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tarform);
        departuredate = (EditText) findViewById(R.id.departure_date);
    }

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

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener{

    int selectyear, selectmonth, selectday;
    public String date;

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current date as the default date in the picker
        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);
        return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    public void onDateSet(DatePicker view, int year, int month, int day) {

        selectday = day;
        selectmonth = month+1;
        selectyear = year;
        date = selectday + "-" + selectmonth + "-" + selectyear;
    }
}

和
日期选择器片段
代码为：

public class TARForm extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener {

    EditText departuredate;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tarform);
        departuredate = (EditText) findViewById(R.id.departure_date);
    }

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

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener{

    int selectyear, selectmonth, selectday;
    public String date;

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current date as the default date in the picker
        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);
        return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    public void onDateSet(DatePicker view, int year, int month, int day) {

        selectday = day;
        selectmonth = month+1;
        selectyear = year;
        date = selectday + "-" + selectmonth + "-" + selectyear;
    }
}

如果您能提供这些信息，我如何将“日期”输入MainActivity departuredate？谢谢。
您可以在onDateSet（）方法中的片段中尝试以下代码

    //In your actiivty
String date=null;

public void setDate(String date){
    this.date=date;
    //set this date in your text View
}


   //In your fragment

Context context;
@Override
public void onAttach(Context context){
    this.context=context;
}

public void onDateSet(DatePicker view, int year, int month, int day){
    String date=//get Date over here
    ((TARForm)context).setDate(date)
}

public void onDateSet(DatePicker view, int year, int month, int day) {

        selectday = day;
        selectmonth = month+1;
        selectyear = year;
        date = selectday + "-" + selectmonth + "-" + selectyear;

        if(getActivity() instanceOf TARForm){
           ((TARForm)getActivity()).departuredate.setText(date);
        }
    }

并在您的TARForm活动中制作
公共编辑文本发布日期如果你的活动和片段在不同的文件夹中
你是否可以用一个例子解释一下，我是android新手。你是否像我说的那样尝试过？好的，让我知道应用程序在测试时崩溃了。错误：android.util.SuperNotCalledException:Fragment DatePickerFragment{884caec#0 datePicker}未调用super.onAttach（）。是的，在onAttach（）中，您必须在此之前调用super.onAttach（）。context=contextI正在共享我的主要活动和Fragment类的代码。请帮助。您可以使用
OnDismissListener
，请检查此使用界面/回调更新我的答案check@rodaxyz请接受答案以结束此问题