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2021.09.30 수업일지(안드로이드 개발 기초, Firebase)

2021.09.30 수업일지(안드로이드 개발 기초, Firebase)

- 파이어베이스를 이용해서 DB를 활용할 수 있도록 하겠다. object로 이뤄진 DB를 제공해준다. 구글에서 서비스한다.

- build.gradle - version 수정

apply plugin: 'com.android.application' android { compileSdkVersion 30 <<<--- buildToolsVersion "30.0.0" <<<--- defaultConfig { applicationId "com.example.ex06" minSdkVersion 26 <<<--- targetSdkVersion 30 <<<--- versionCode 1 versionName "1.0" testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro' } } compileOptions { sourceCompatibility JavaVersion.VERSION_1_8 targetCompatibility JavaVersion.VERSION_1_8 } } dependencies { implementation fileTree(dir: "libs", include: ["*.jar"]) implementation 'androidx.appcompat:appcompat:1.3.1' implementation 'androidx.constraintlayout:constraintlayout:2.1.0' testImplementation 'junit:junit:4.12' androidTestImplementation 'androidx.test.ext:junit:1.1.3' androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0' implementation 'com.android.support:design:30.0.0' <<<--- }

확인

- 메모장 어플을 만들어보도록 하겠다.

- 사용자에 따라서 로그인(인증)을 통해 개별 메모장을 가질 수 있도록 하겠다.

- 파이어베이스를 통해서 인증작업을 하도록 하겠다.

- Authentication click -> Email and password authentication click -> 1. connect to Firebase -> google account login -> android studio login fin

콘솔로 이동

파이어베이스 시작

새로운 프로젝트 새성

로그인 인증방법 설정 accept changes click

적용 및 다운로드 확인

- build.gradle - 파이어베이스 설치 확인

..... dependencies { implementation fileTree(dir: "libs", include: ["*.jar"]) implementation 'androidx.appcompat:appcompat:1.3.1' implementation 'androidx.constraintlayout:constraintlayout:2.1.0' implementation 'com.google.firebase:firebase-auth:16.0.5' <<<--- testImplementation 'junit:junit:4.12' androidTestImplementation 'androidx.test.ext:junit:1.1.3' androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0' implementation 'com.android.support:design:30.0.0' }

프로젝트 신규 앱 등록

앱 패키지 네임과 앱 닉네임 설정

다운받은 데이터 경로

다음 다음 다음 후 아래

설정 끝 확인

앱 추가 확인

권한 및 사용자 확인 아직 사용자 추가는 안한다.

- 로그인 화면을 꾸며보도록 하겠다.

- src/main/res/layout/activity_main.xml

확인

- 이제 버튼을 클릭속성을 지정하여 특정 메서드를 실행하도록 하겠다.

.....

- 메서드를 생성하겠다.

- src/main/java/com/example/ex06/MainActivity.java

package com.example.ex06; import androidx.annotation.NonNull; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.EditText; import android.widget.Toast; import com.google.android.gms.tasks.OnCompleteListener; import com.google.android.gms.tasks.Task; import com.google.firebase.auth.AuthResult; import com.google.firebase.auth.FirebaseAuth; public class MainActivity extends AppCompatActivity { // 값을 가지고 오기 위한 전역변수 EditText email, password; // 회원등록을 위한 firebaseauth FirebaseAuth mAuth; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 값 가지고 오기 email = findViewById(R.id.email); password = findViewById(R.id.password); mAuth = FirebaseAuth.getInstance(); getSupportActionBar().setTitle("로그인"); } // View는 모든 위젯의 상위 public void mClick(View v){ String strEmail = email.getText().toString(); String strPassword = password.getText().toString(); switch (v.getId()){ case R.id.login: break; case R.id.register: // 유저생성을 위한 메서드 mAuth.createUserWithEmailAndPassword(strEmail, strPassword) .addOnCompleteListener(this, new OnCompleteListener() { @Override public void onComplete(@NonNull Task task) { if(task.isSuccessful()){ Toast.makeText(MainActivity.this,"등록성공",Toast.LENGTH_SHORT).show(); }else{ Toast.makeText(MainActivity.this,"등록실패",Toast.LENGTH_SHORT).show(); } } }); break; } } }

파이어베이스에서 확인할 수 있다.

- password 입력시 안보이게 하겠다.

- src/main/java/com/example/ex06/MemoActivity.java

..... .....

- 이제 해당 계정을 가지고 로그인 하는 작업을 하도록 하겠다.

- src/main/java/com/example/ex06/MainActivity.java

..... // View는 모든 위젯의 상위 public void mClick(View v){ String strEmail = email.getText().toString(); String strPassword = password.getText().toString(); switch (v.getId()){ case R.id.login: mAuth.signInWithEmailAndPassword(strEmail,strPassword) .addOnCompleteListener(this, new OnCompleteListener() { @Override public void onComplete(@NonNull Task task) { if(task.isSuccessful()){ Toast.makeText(MainActivity.this,"로그인성공",Toast.LENGTH_SHORT).show(); }else{ Toast.makeText(MainActivity.this,"로그인실패",Toast.LENGTH_SHORT).show(); } } }); break; .....

- src/main/java/com/example/ex06/MemoActivity.java

package com.example.ex06; import androidx.annotation.NonNull; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.MenuItem; import com.google.firebase.auth.FirebaseAuth; import com.google.firebase.auth.FirebaseUser; public class MemoActivity extends AppCompatActivity { FirebaseUser user; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_memo); // 현재 로그인 유저 정보 user = FirebaseAuth.getInstance().getCurrentUser(); String email = user.getEmail(); // 해당 유저의 이메일 getSupportActionBar().setTitle(email); getSupportActionBar().setDisplayHomeAsUpEnabled(true); } @Override public boolean onOptionsItemSelected(@NonNull MenuItem item) { switch (item.getItemId()){ case android.R.id.home: finish(); } return super.onOptionsItemSelected(item); } }

- src/main/java/com/example/ex06/(new)MemoActivity.java

..... // View는 모든 위젯의 상위 public void mClick(View v){ String strEmail = email.getText().toString(); String strPassword = password.getText().toString(); switch (v.getId()){ case R.id.login: mAuth.signInWithEmailAndPassword(strEmail,strPassword) .addOnCompleteListener(this, new OnCompleteListener() { @Override public void onComplete(@NonNull Task task) { if(task.isSuccessful()){ Intent intent = new Intent(MainActivity.this, MemoActivity.class); startActivity(intent); }else{ Toast.makeText(MainActivity.this,"로그인실패",Toast.LENGTH_SHORT).show(); } } }); break; .....

확인

- 이제 메모장의 CRUD 작업을 하겠다.

- 리얼타임 DB 라이브러리를 추가하겠다.

Tools -> Firebase

Add -> accept

설치 후 Firebase 홈에서 확인

잠금모드로 시작 후 사용 설정

규칙을 true로 변경하고 위에 게시를 클릭하여 적용

데이터가 오브젝트 형식으로 저장되어 있다.

- build.gradle - > 라이브러리 확인

..... dependencies { implementation fileTree(dir: "libs", include: ["*.jar"]) implementation 'androidx.appcompat:appcompat:1.3.1' implementation 'androidx.constraintlayout:constraintlayout:2.1.0' implementation 'com.google.firebase:firebase-auth:16.0.5' implementation 'com.google.firebase:firebase-database:16.0.4' <<<--- testImplementation 'junit:junit:4.12' androidTestImplementation 'androidx.test.ext:junit:1.1.3' androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0' implementation 'com.android.support:design:30.0.0' }

- 이제 입력프로그램을 만들겠다.

- src/main/res/drawable/(new)ic_write.xml

- src/main/res/layout/activity_memo.xml

-src/main/java/com/example/ex06/(new)WriteActivity.java

package com.example.ex06; import androidx.annotation.NonNull; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.MenuItem; public class WriteActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_write); getSupportActionBar().setTitle("메모작성"); getSupportActionBar().setDisplayHomeAsUpEnabled(true); } @Override public boolean onOptionsItemSelected(@NonNull MenuItem item) { switch (item.getItemId()){ case android.R.id.home: finish(); } return super.onOptionsItemSelected(item); } }

- src/main/java/com/example/ex06/MemoActivity.java

..... @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_memo); // 현재 로그인 유저 정보 user = FirebaseAuth.getInstance().getCurrentUser(); String email = user.getEmail(); // 해당 유저의 이메일 getSupportActionBar().setTitle(email); getSupportActionBar().setDisplayHomeAsUpEnabled(true); FloatingActionButton write = findViewById(R.id.write); <<<--- write.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(MemoActivity.this, WriteActivity.class); startActivity(intent); } }); } .....

- src/main/res/layout/activity_write.xml

확인

- 메모를 작성하고 DB에 저장하도록 하겠다.

- src/main/java/com/example/ex06/(new)Memo.java - java class

package com.example.ex06; public class Memo { private String key; private String content; private String createDate; private String updateDate; ..... getter and setter toSring

- src/main/java/com/example/ex06/WriteActivity.java

..... public class WriteActivity extends AppCompatActivity { EditText content; <<<---- @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_write); getSupportActionBar().setTitle("메모작성"); getSupportActionBar().setDisplayHomeAsUpEnabled(true); content = findViewById(R.id.content); <<<---- FloatingActionButton write = findViewById(R.id.write); write.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String strContent = content.getText().toString(); if(strContent.equals("")){ AlertDialog.Builder box = new AlertDialog.Builder(WriteActivity.this); box.setMessage("내용을 입력하세요."); box.setPositiveButton("닫기",null); box.show(); }else{ Memo memo = new Memo(); memo.setContent(strContent); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); memo.setCreateDate(sdf.format(new Date())); System.out.println(memo.toString()); } } }); } .....

콘솔에 찍어보았다.

- 이제 DB에 넣어보자.

..... public class WriteActivity extends AppCompatActivity { EditText content; // DB에 저장하기 위한 유저정보 가지고 오기 <<<--- FirebaseAuth mAuth; FirebaseDatabase db; DatabaseReference mRef; FirebaseUser user; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_write); mAuth = FirebaseAuth.getInstance(); <<<--- user = mAuth.getCurrentUser(); <<<--- getSupportActionBar().setTitle("메모작성"); getSupportActionBar().setDisplayHomeAsUpEnabled(true); content = findViewById(R.id.content); FloatingActionButton write = findViewById(R.id.write); write.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String strContent = content.getText().toString(); AlertDialog.Builder box; if(strContent.equals("")){ box = new AlertDialog.Builder(WriteActivity.this); box.setMessage("내용을 입력하세요."); box.setPositiveButton("닫기",null); box.show(); }else{ <<<--- Memo memo = new Memo(); memo.setContent(strContent); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); memo.setCreateDate(sdf.format(new Date())); System.out.println(memo.toString()); box = new AlertDialog.Builder(WriteActivity.this); box.setMessage("내용을 저장하시겠습니까?"); box.setNegativeButton("아니오",null); box.setPositiveButton("예", null); box.show(); } } }); } .....

확인

- 혹시 데이터가 안들어가고 오류가 발생한다며 아래의 페이지에서 안내하는대로 해보자.

https://simpleneed.tistory.com/74

- DB에 다른 계정 2개로 데이터가 들어가는지 확인해보자.

..... public class WriteActivity extends AppCompatActivity { EditText content; FirebaseAuth mAuth; FirebaseDatabase db; DatabaseReference mRef; FirebaseUser user; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_write); mAuth = FirebaseAuth.getInstance(); user = mAuth.getCurrentUser(); db = FirebaseDatabase.getInstance(); <<<---- getSupportActionBar().setTitle("메모작성"); getSupportActionBar().setDisplayHomeAsUpEnabled(true); content=findViewById(R.id.content); FloatingActionButton write=findViewById(R.id.write); write.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String strContent = content.getText().toString(); if(strContent.equals("")){ AlertDialog.Builder box=new AlertDialog.Builder(WriteActivity.this); box.setMessage("내용을 입력하세요!"); box.setPositiveButton("닫기", null); box.show(); }else { Memo memo = new Memo(); memo.setContent(strContent); SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); memo.setCreateDate(sdf.format(new Date())); System.out.println(memo.toString()); AlertDialog.Builder box=new AlertDialog.Builder(WriteActivity.this); box.setMessage("내용을 저장하실래요"); box.setPositiveButton("예", new DialogInterface.OnClickListener() { <<<---- @Override public void onClick(DialogInterface dialog, int which) { mRef = db.getReference("memos").child(user.getUid()).push(); mRef.setValue(memo); finish(); } }); box.setNeutralButton("아니오", null); box.show(); } } }); } .....

확인

- 이제 memo 액티비티를 꾸미고 해당 액티비티에 들어갈 아이템 레이아웃을 만들자.

- src/main/res/layout/(new)item_memo.xml

- src/main/java/com/example/ex06/MemoActivity.java

..... public class MemoActivity extends AppCompatActivity { MemoAdapter memoAdapter = new MemoAdapter(); <<<<---- ArrayList array = new ArrayList<>(); <<<<---- ListView list; <<<<---- FirebaseDatabase database; <<<<---- FirebaseUser user; DatabaseReference ref; <<<<---- @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_memo); list = findViewById(R.id.list); // 현재 로그인 유저 정보 user = FirebaseAuth.getInstance().getCurrentUser(); String email = user.getEmail(); // 해당 유저의 이메일 getSupportActionBar().setTitle(email); getSupportActionBar().setDisplayHomeAsUpEnabled(true); FloatingActionButton write = findViewById(R.id.write); write.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(MemoActivity.this, WriteActivity.class); startActivity(intent); } }); // 생성시 데이터를 가지고옴 // memos 아래 user id의 데이터를 가지고옴 database = FirebaseDatabase.getInstance(); <<<<---- ref = database.getReference("memos/"+user.getUid()); <<<<---- ref.addChildEventListener(new ChildEventListener() { <<<<---- @Override public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) { Memo memo = (Memo)dataSnapshot.getValue(Memo.class); memo.setKey(dataSnapshot.getKey()); array.add(memo); list.setAdapter(memoAdapter); } @Override public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) { } @Override public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) { } @Override public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) { } @Override public void onCancelled(@NonNull DatabaseError databaseError) { } }); } @Override public boolean onOptionsItemSelected(@NonNull MenuItem item) { switch (item.getItemId()){ case android.R.id.home: finish(); } return super.onOptionsItemSelected(item); } class MemoAdapter extends BaseAdapter{ <<<<---- @Override public int getCount() { return array.size(); } @Override public Object getItem(int i) { return null; } @Override public long getItemId(int i) { return 0; } @Override public View getView(int i, View view, ViewGroup viewGroup) { view = getLayoutInflater().inflate(R.layout.item_memo,viewGroup,false); Memo memo = array.get(i); TextView content = view.findViewById(R.id.content); content.setText(memo.getContent()); TextView createDate = view.findViewById(R.id.createDate); createDate.setText(memo.getCreateDate()); return view; } } }

확인

- 리드 작업을 할 수 있는 리드 엑티비티를 생성하겠다.

- src/main/java/com/example/ex06/(new)ReadActivity.java

package com.example.ex06; import androidx.annotation.NonNull; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.MenuItem; public class ReadActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_write); getSupportActionBar().setTitle("메모정보"); getSupportActionBar().setDisplayHomeAsUpEnabled(true); } @Override public boolean onOptionsItemSelected(@NonNull MenuItem item) { switch (item.getItemId()){ case android.R.id.home: finish(); break; } return super.onOptionsItemSelected(item); } }

- src/main/res/layout/item_memo.xml

<<<--- .....

- src/main/java/com/example/ex06/MemoActivity.java

..... @Override public View getView(int i, View view, ViewGroup viewGroup) { view = getLayoutInflater().inflate(R.layout.item_memo,viewGroup,false); Memo memo = array.get(i); LinearLayout item = view.findViewById(R.id.item); item.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(MemoActivity.this, ReadActivity.class); intent.putExtra("key", memo.getKey()); intent.putExtra("content",memo.getContent()); intent.putExtra("createDate",memo.getCreateDate()); intent.putExtra("updateDate",memo.getUpdateDate()); startActivity(intent); } }); TextView content = view.findViewById(R.id.content); content.setText(memo.getContent()); TextView createDate = view.findViewById(R.id.createDate); createDate.setText(memo.getCreateDate()); return view; } } }

- src/main/java/com/example/ex06/ReadActivity.java

..... @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_read); getSupportActionBar().setTitle("메모정보"); getSupportActionBar().setDisplayHomeAsUpEnabled(true); Intent intent = getIntent(); String key = intent.getStringExtra("key"); System.out.println("!!!!!!!!!!!!!!!!!!!!!!"+key); } .....

확인

- src/main/java/com/example/ex06/ReadActivity.java

public class ReadActivity extends AppCompatActivity { FirebaseDatabase database; DatabaseReference ref; Memo memo = new Memo(); EditText content; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_write); content = findViewById(R.id.content); getSupportActionBar().setTitle("메모정보"); getSupportActionBar().setDisplayHomeAsUpEnabled(true); Intent intent = getIntent(); String key = intent.getStringExtra("key"); memo.setKey(intent.getStringExtra("key")); memo.setContent(intent.getStringExtra("content")); memo.setCreateDate(intent.getStringExtra("createDate")); memo.setUpdateDate(intent.getStringExtra("updateDate")); System.out.println(memo.toString()); content.setText(memo.getContent()); FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser(); database = FirebaseDatabase.getInstance(); ref = database.getReference("memos/"+user.getUid()+"/"+key); } @Override public boolean onOptionsItemSelected(@NonNull MenuItem item) { switch (item.getItemId()){ case android.R.id.home: finish(); break; } return super.onOptionsItemSelected(item); } }

확인

- 이제 정보를 수정하겠다.

- src/main/java/com/example/ex06/ReadActivity.java

..... @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_write); content = findViewById(R.id.content); getSupportActionBar().setDisplayHomeAsUpEnabled(true); Intent intent = getIntent(); String key = intent.getStringExtra("key"); memo.setKey(intent.getStringExtra("key")); memo.setContent(intent.getStringExtra("content")); memo.setCreateDate(intent.getStringExtra("createDate")); memo.setUpdateDate(intent.getStringExtra("updateDate")); System.out.println(memo.toString()); content.setText(memo.getContent()); getSupportActionBar().setTitle("메모정보 / 작성일 : "+memo.getCreateDate()); FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser(); database = FirebaseDatabase.getInstance(); ref = database.getReference("memos/"+user.getUid()+"/"+key); FloatingActionButton write = findViewById(R.id.write); <<<--- write.setOnClickListener(new View.OnClickListener() { <<<--- @Override public void onClick(View view) { AlertDialog.Builder box = new AlertDialog.Builder(ReadActivity.this); box.setMessage("수정하시겠습니까?"); box.setPositiveButton("예", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { memo.setContent(content.getText().toString()); SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); memo.setUpdateDate(df.format(new Date())); ref.setValue(memo); finish(); } }); box.setNegativeButton("아니오",null); box.show(); } }); } .....

- src/main/java/com/example/ex06/MemoActivity.java

..... @Override protected void onRestart() { super.onRestart(); readMemos(); } public void readMemos(){ array.clear(); ref.addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) { Memo memo = (Memo)dataSnapshot.getValue(Memo.class); memo.setKey(dataSnapshot.getKey()); array.add(memo); memoAdapter.notifyDataSetChanged(); } @Override public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) { } @Override public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) { } @Override public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) { } @Override public void onCancelled(@NonNull DatabaseError databaseError) { } }); } }

- src/main/res/layout/item_memo.xml

.....

- src/main/java/com/example/ex06/MemoActivity.java

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_memo); list = findViewById(R.id.list); list.setAdapter(memoAdapter); // 현재 로그인 유저 정보 user = FirebaseAuth.getInstance().getCurrentUser(); String email = user.getEmail(); // 해당 유저의 이메일 getSupportActionBar().setTitle(email); getSupportActionBar().setDisplayHomeAsUpEnabled(true); FloatingActionButton write = findViewById(R.id.write); write.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(MemoActivity.this, WriteActivity.class); startActivity(intent); } }); // 생성시 데이터를 가지고옴 // memos 아래 user id의 데이터를 가지고옴 database = FirebaseDatabase.getInstance(); ref = database.getReference("memos/"+user.getUid()); readMemos(); <<<--- } ..... @Override public View getView(int i, View view, ViewGroup viewGroup) { view = getLayoutInflater().inflate(R.layout.item_memo,viewGroup,false); Memo memo = array.get(i); LinearLayout item = view.findViewById(R.id.item); item.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(MemoActivity.this, ReadActivity.class); intent.putExtra("key", memo.getKey()); intent.putExtra("content",memo.getContent()); intent.putExtra("createDate",memo.getCreateDate()); intent.putExtra("updateDate",memo.getUpdateDate()); startActivity(intent); } }); TextView content = view.findViewById(R.id.content); content.setText(memo.getContent()); TextView createDate = view.findViewById(R.id.createDate); createDate.setText(memo.getCreateDate()); TextView updateDate = view.findViewById(R.id.updateDate); <<<--- updateDate.setText(memo.getUpdateDate()); return view; } .....

- 삭제 하도록 하겠다.

- src/main/res/(new)menu/(new)read.xml - android resources file

- src/main/java/com/example/ex06/ReadActivity.java

..... @Override public boolean onOptionsItemSelected(@NonNull MenuItem item) { switch (item.getItemId()){ case R.id.delete: <<<--- AlertDialog.Builder box = new AlertDialog.Builder(this); box.setMessage("삭제하시겠습니까?"); box.setNegativeButton("아니오", null); box.setPositiveButton("예", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { ref.removeValue(); finish(); } }); box.show(); break; case android.R.id.home: finish(); break; } return super.onOptionsItemSelected(item); } @Override <<<--- public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.read,menu); return super.onCreateOptionsMenu(menu); } }

from http://becomefullstackdev.tistory.com/100 by ccl(A) rewrite - 2021-09-30 17:27:44