将字符串从对话框片段返回到活动 [英] Returning String from Dialog Fragment back to Activity

问题描述

我已经阅读了很多关于此的帖子，但我找不到任何适用于此案例的帖子.

I have read many posts on this but I can't find any that apply to this case.

我有一个时间选择器对话框，我已将整数值放在一个字符串中，我需要将此字符串返回到主要活动.

I have a time picker dialog and I have put the integer values together in a string and I need to get this string back to the main activity.

这个字符串值将用于设置按钮的文本.

This string value will then be used to set the text of a button.

如果有人可以帮助我，将不胜感激.

If someone could help me with this it would be most appreciated.

谢谢

对话框片段

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
        String Time =Integer.toString(hourOfDay) + " : " + Integer.toString(minute);
    }
}

代码

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


        Button btn = (Button) findViewById(R.id.start_time_button);
        Button.setText(Time);


    }

推荐答案

首选方法是使用回调从 Fragment 获取信号.另外，这也是Android在与Activity通信

The preferred method is to use a callback to get a signal from a Fragment. Also, this is the recommended method proposed by Android at Communicating with the Activity

对于您的示例，在您的 DialogFragment 中，添加一个接口并注册它.

For your example, in your DialogFragment, add an interface and register it.

public static interface OnCompleteListener {
    public abstract void onComplete(String time);
}

private OnCompleteListener mListener;

// make sure the Activity implemented it
@Override
public void onAttach(Activity activity) {
    super.onAttach(activity); 
    try {
        this.mListener = (OnCompleteListener)activity;
    }
    catch (final ClassCastException e) {
        throw new ClassCastException(activity.toString() + " must implement OnCompleteListener");
    }
}

现在在你的Activity

public class MyActivity extends Activity implements MyDialogFragment.OnCompleteListener {
    //...

    public void onComplete(String time) {
        // After the dialog fragment completes, it calls this callback.
        // use the string here
    }
}

现在在您的 DialogFragment 中，当用户单击 OK 按钮时，通过您的回调将该值发送回 Activity.

Now in your DialogFragment, when a user clicks the OK button, send that value back to the Activity via your callback.

public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
    String time = Integer.toString(hourOfDay) + " : " + Integer.toString(minute);
    this.mListener.onComplete(time);
}

这篇关于将字符串从对话框片段返回到活动的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！