什么可以用作上下文的第一个参数？

Question

这是我创建的 TimePicker class 的代码

picker.java

package com.example.abhijeet.todo;

import android.app.Dialog;
import android.app.DialogFragment;
import android.app.TimePickerDialog;
import android.content.Context;
import android.os.Bundle;
import android.text.format.DateFormat;
import android.view.View;
import android.widget.EditText;
import android.widget.TimePicker;

import java.util.Calendar;

/**
 * Created by Abhijeet on 9/6/2017.
 */

public class Picker 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()));
    }



    @Override
    public void onTimeSet(TimePicker timePicker, int i, int i1) {
        //Creating a View object because this class do not extend from activity class so no findviewbyid() method is present
       View v =View.inflate(*  ?   *,R.layout.activity_editor,null);  //HERE
        //Displaying the user selected time on the Edit Text view
        EditText edittime = (EditText) v.findViewById(R.id.time_editext_field);


    }
}

我正在尝试在编辑文本框中显示通过选择器选择的时间。我无法找到论点的正确上下文。

我已经阅读了答案 here，其中解释了上下文的不同用法，但这似乎对我没有帮助。

感谢您提前的帮助。

Answer 1

直接打电话getContext()

作为DialogFragment is child of Fragment。所以所有的Fragmentclass方法都可以在DialogFragment中调用。

像这样

@Override
    public void onTimeSet(TimePicker timePicker, int i, int i1) {
        //Creating a View object because this class do not extend from activity class so no findviewbyid() method is present
       View v =View.inflate(getContext() ,R.layout.activity_editor,null);  //HERE
        //Displaying the user selected time on the Edit Text view
        EditText edittime = (EditText) v.findViewById(R.id.time_editext_field);
    }

您也可以调用getActivity()方法。如果您定位到年龄大于 API 的 23 岁：

@Override
    public void onTimeSet(TimePicker timePicker, int i, int i1) {
        //Creating a View object because this class do not extend from activity class so no findviewbyid() method is present
       View v =View.inflate(getActivity() ,R.layout.activity_editor,null);  //HERE
        //Displaying the user selected time on the Edit Text view
        EditText edittime = (EditText) v.findViewById(R.id.time_editext_field);
    }

Answer 2

无论何时你都被利用。 Activity -> getApplicationContext(), Fragment -> getActivity(), Adapter -> getContext()

什么可以用作上下文的第一个参数？

What can use as the first argument for the context?

android

android-context