안드로이드 이론 빡공 11

 

 

@Override
public void onAttach(@NonNull Context context) {
    super.onAttach(context);
    //여기서는 메인액티비티를 나타냄
    if(context instanceof imageSelectionCallback ){
        callback = (imageSelectionCallback) context;
    }

}

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_list,container,false);

    Button button = rootView.findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
          if(callback!=null){
             callback.onImageSelected(1);
          }
        }
    });

package com.threedpit.myfragment2;

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentManager;

import android.os.Bundle;
import android.widget.ViewSwitcher;

import java.util.List;

public class MainActivity extends AppCompatActivity implements imageSelectionCallback{
    ListFragment listFragment;
    Viewerfragment viewerfragment;
    //이미지자체를 배열에 넣어 인덱스 0,1,2를 가지게함
    int[] images = {R.drawable.spring,R.drawable.summer,R.drawable.fall};

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

        //메인액티비티에 프래그먼트를 띄우기 위한 초기 설정
       FragmentManager manager = getSupportFragmentManager();
       listFragment = (ListFragment) manager.findFragmentById(R.id.listFragment);
       viewerfragment = (Viewerfragment) manager.findFragmentById(R.id.viewerFragment);

    }

    //이미지를 바꾸게 하기 위한 메소드 implements 구현을 사용하여 메소드 오버라이딩하여 사용

    // public 으로 쓰여있어서 어디서는 실행이 가능
    @Override
    public void onImageSelected(int position) {
        //이렇게하면 뷰어프래그먼트 화면에 이미지를 띄우겠다 생각하면된다.
         viewerfragment.setImage(images[position]);
    }
}

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >


    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">
        <fragment
            android:id="@+id/listFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:name="com.threedpit.myfragment2.ListFragment"/>
    </FrameLayout>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">
        <fragment
            android:id="@+id/viewerFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:name="com.threedpit.myfragment2.Viewerfragment"
        />

    </FrameLayout>
</LinearLayout>

package com.threedpit.myfragment2;

import android.Manifest;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public class ListFragment extends Fragment {
    //구현 클래스 부분 변수 하나 생성해서
    imageSelectionCallback callback;

    @Override
    public void onAttach(@NonNull Context context) {
        //프래그먼트가 액티비티에 나타날때 제일 먼저 실행되는 메소드
        super.onAttach(context);
        //여기서는 메인액티비티를 나타냄
        //onAttach에서 받아지는 부분이 현재 프래그먼트가 띄워지는 액티비티
        //여기서는 메인 액티비티
        if(context instanceof imageSelectionCallback ){
            callback = (imageSelectionCallback) context;
        }

    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_list,container,false);

        //봄 화면 나타내는 버튼
        Button button = rootView.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //프래그먼트는 액티비티 위에 생성되는것으로
                //혹시나 액티비티가 없는 경우가 있을수 잇으니
                // 널 값을 확인 하고 이미지 변경해주는 메소드 실행
              if(callback!=null) {
                  callback.onImageSelected(0);
              }
            }
        });

        //여름 화면 나타내는 버튼
        Button button2 = rootView.findViewById(R.id.button2);
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(callback!=null){
                    callback.onImageSelected(1);
                }
            }
        });

        //가을 화면 나타내는 버튼
        Button button3 = rootView.findViewById(R.id.button3);
        button3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(callback!=null){
                    callback.onImageSelected(2);
                }
            }
        });
        return rootView;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="봄" />

    <Button
        android:id="@+id/button2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="여름" />

    <Button
        android:id="@+id/button3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="가을" />
</LinearLayout>

 

package com.threedpit.myfragment2;

import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public class Viewerfragment extends Fragment {
    ImageView imageView;


    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_viewer,container,false);

        imageView = rootView.findViewById(R.id.imageView);

        return rootView;
    }
    public void setImage(int resID){
        //이미지 변경해주는 메소드
        imageView.setImageResource(resID);
    }
}

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:srcCompat="@drawable/spring" />
</LinearLayout>