安卓作业—-慕课移动应用开发作业21之使用Sqlite+RecyclerView+Dialog对数据进行增删改查移动开发baidu41860619的博客-

本篇使用Sqlite+RecyclerView+Dialog对数据进行增删改查

同时这也是中国大学慕课移动终端应用开发的网课作业21

原题目要求：
（1）通过“添加联系人”按钮，跳转到“添加”信息的Dialog输入用户名、联系电话、地址选择性别，添加后显示到联系人列表。
（2）点击 联系人中的项，可以弹出Dialog，修改联系人信息或者删除联系人。
（3）可以通过输入姓名进行联系人信息的查找，并给出信息。

说明

1.此篇博文是代码部分，一些有关于实现的细节，感兴趣的同学可以看一下此篇博文
2.建议阅读《安卓编程权威指南3》，里面有关Sqlite的代码的格式值得学习，或者说，整本书的代码风格都是值得学习的
3.我会持续更新我的作业，关注不迷路哈

效果图

代码

目录结构

这是我的目录结构，adapter包下是适配器，dao包下是访问数据库的接口和实现方法，database包下是一些有关数据库的类，dialog包下是自定义对话框，model包下是数据模型

添加依赖

由于使用了RecyclerView，所以得添加依赖

implementation 'com.android.support:recyclerview-v7:28.0.0' 

具体代码

1.User.java

public class User { private UUID id; private String name; private String phone; private String address; private int sex; public User() { } public UUID getId() { return id; } public void setId(UUID id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public int getSex() { return sex; } public void setSex(int sex) { this.sex = sex; } public User(UUID id, String name, String phone, String address, int sex) { this.id = id; this.name = name; this.phone = phone; this.address = address; this.sex = sex; } public User(String name, String phone, String address, int sex) { this.id =UUID.randomUUID(); this.name = name; this.phone = phone; this.address = address; this.sex = sex; } } 

2.UserCursorWrapper.java

public class UserCursorWrapper extends CursorWrapper { /**      * Creates a cursor wrapper.      *      * @param cursor The underlying cursor to wrap.      */ public UserCursorWrapper(Cursor cursor) { super(cursor); } public User getUser(){ //获取每行数据         String uuidString = getString(getColumnIndex(UserDbSchema.UserTable.Columns.UUID));         String name = getString(getColumnIndex(UserDbSchema.UserTable.Columns.NAME));         String phone = getString(getColumnIndex(UserDbSchema.UserTable.Columns.PHONE));         String address = getString(getColumnIndex(UserDbSchema.UserTable.Columns.ADDRESS)); int sex = getInt(getColumnIndex(UserDbSchema.UserTable.Columns.SEX)); return new User(UUID.fromString(uuidString),name,phone,address,sex); } } 

3.UserDbSchema.java

public class UserDbSchema { //利用内部类定义user表结构 public static final class UserTable{ //定义表名 public static final String TABLE_NAME = "user"; //定义数据表字段 public static final class Columns{ public static final String UUID = "uuid"; public static final String NAME = "name"; public static final String PHONE = "phone"; public static final String ADDRESS = "address"; public static final String SEX = "sex"; } } } 

4.UserSqlHelper.java

public class UserSqlHelper extends SQLiteOpenHelper { private static final int VERSION = 1;//定义版本 private static final String DATABASE_NAME = "course21DataBase"; public UserSqlHelper(Context context) { super(context, DATABASE_NAME, null, VERSION); } @Override public void onCreate(SQLiteDatabase db) { /**             此时数据库是没有被创建或者打开的，             直到getReadableDatabase,getWritableDatabase这两个方法其中一个被调用          */         db.execSQL("create table "+ UserDbSchema.UserTable.TABLE_NAME+ "("+"_id integer primary key autoincrement,"+                 UserDbSchema.UserTable.Columns.UUID+","+                 UserDbSchema.UserTable.Columns.NAME+","+                 UserDbSchema.UserTable.Columns.PHONE+","+                 UserDbSchema.UserTable.Columns.ADDRESS+","+                 UserDbSchema.UserTable.Columns.SEX+")" ); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { //不更新数据库 } } 

5.IUserDao.java

public interface IUserDao { /**      * 获取所有用户信息      * */     ArrayList<User> getAllUser(); /**      * 获取指定名字的用户信息,默认名字不重复      * */     User getUserByName(String name); /**      *添加用户信息      * */ void addUser(User user); /**      * 修改指定用户信息      * */ void updateUser(User user); /**      * 删除指定用户信息      * */ void deleteUser(User user); } 

6.UserDao.java

public class UserDao implements IUserDao{ private static UserDao sUserDao; private Context mContext; private SQLiteDatabase mDatabase; public UserDao(Context context) {         mContext = context.getApplicationContext();         mDatabase = new UserSqlHelper(mContext).getWritableDatabase();//此时数据库才是可写的 } /**      * 全局保留一个userDao实例      * */ public static UserDao getUserDao(Context context){ if (sUserDao == null){             sUserDao = new UserDao(context); } return sUserDao; } /**      * 获取所有用户信息      */ @Override public ArrayList<User> getAllUser() {         ArrayList<User> users = new ArrayList<>();         UserCursorWrapper cursorWrapper = queryUsers(null,null); try {             cursorWrapper.moveToFirst(); while (!cursorWrapper.isAfterLast()){                 users.add(cursorWrapper.getUser());                 cursorWrapper.moveToNext(); } } finally {             cursorWrapper.close(); } return users; } /**      * 获取指定名字的用户信息,默认名字不重复      *      * @param name      */ @Override public User getUserByName(String name) { //定义查询条件         String whereClause = UserDbSchema.UserTable.Columns.NAME + " = ?";         String [] whereArgs = new String[]{ name };         UserCursorWrapper cursorWrapper = queryUsers(whereClause,whereArgs); try { //查询失败 if (cursorWrapper.getCount() == 0){ return null; }             cursorWrapper.moveToFirst(); return cursorWrapper.getUser(); } finally { //关闭             cursorWrapper.close(); } } /**      * 添加用户信息      *      * @param user      */ @Override public void addUser(User user) { //防止传入空值 if (user!=null){             ContentValues values = getContentValues(user); //插入数据             mDatabase.insert(UserDbSchema.UserTable.TABLE_NAME,null,values); } } /**      * 修改指定用户信息      *      * @param user      */ @Override public void updateUser(User user) {         String uuidString = user.getId().toString();         ContentValues values = getContentValues(user);         mDatabase.update(UserDbSchema.UserTable.TABLE_NAME,                 values,                 UserDbSchema.UserTable.Columns.UUID+" = ? ", new String[] { uuidString }); } /**      * 删除指定用户信息      *      * @param user      */ @Override public void deleteUser(User user) {         String uuidString = user.getId().toString();         mDatabase.delete(UserDbSchema.UserTable.TABLE_NAME,                 UserDbSchema.UserTable.Columns.UUID+" = ? ", new String[] { uuidString }); } //私有方法，返回一个ContentValues对象 private ContentValues getContentValues(User user){         ContentValues values = new ContentValues(); //添加键值对         values.put(UserDbSchema.UserTable.Columns.UUID,user.getId().toString());         values.put(UserDbSchema.UserTable.Columns.NAME,user.getName());         values.put(UserDbSchema.UserTable.Columns.PHONE,user.getPhone());         values.put(UserDbSchema.UserTable.Columns.ADDRESS,user.getAddress());         values.put(UserDbSchema.UserTable.Columns.SEX,user.getSex()); return values; } /**      *  查询记录，返回一个CursorWrapper对象，可以调用里面的getUser（）方法获得User值      *      *  不管是查询特殊还是全部，都可以调用此方法      */ private UserCursorWrapper queryUsers(String whereClause,String [] whereArgs){         Cursor cursor = mDatabase.query(                 UserDbSchema.UserTable.TABLE_NAME,                 null,                 whereClause,                 whereArgs,                 null,                 null,                 null         ); return new UserCursorWrapper(cursor); } } 

7.UserAdapter.java

public class UserAdapter extends RecyclerView.Adapter<UserAdapter.ViewHolder>{ private ArrayList<User> mUsers; private Context mContext;//上下文对象 private LayoutInflater mInflater; private DialogListener mListener = new DialogListener() { @Override public void sendMessage() { updateView(); } }; public UserAdapter(Context context,ArrayList<User> users) {         mUsers = users;         mContext = context;         mInflater = LayoutInflater.from(mContext); } @NonNull @Override public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {         View view = mInflater.inflate(R.layout.info_item, parent, false);         ViewHolder holder = new ViewHolder(view); return holder; } @Override public void onBindViewHolder(@NonNull ViewHolder holder,int position) { //        mPosition = position; final User user = mUsers.get(position); //性别决定照片         holder.mImageView.setImageResource(user.getSex()==1?R.drawable.boy:R.drawable.girl);         holder.mTextViewPhone.setText("电话: "+user.getPhone());         holder.mTextViewName.setText(user.getName());         holder.mTextViewAddress.setText("地址: "+user.getAddress()); //点击之后弹出一个对话框         holder.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) {                 UpdateDialog dialog = new UpdateDialog(mContext,user,mListener);                 dialog.show(); } }); } public void updateView(){         mUsers =  UserDao.getUserDao(mContext).getAllUser(); notifyDataSetChanged(); } @Override public int getItemCount() { return mUsers.size(); } class ViewHolder extends RecyclerView.ViewHolder{ public ImageView mImageView; public TextView mTextViewName,mTextViewAddress,mTextViewPhone; public ViewHolder(@NonNull View itemView) { super(itemView);             mImageView = itemView.findViewById(R.id.info_image);             mTextViewName = itemView.findViewById(R.id.info_name);             mTextViewAddress = itemView.findViewById(R.id.info_address);             mTextViewPhone = itemView.findViewById(R.id.info_phone); } } } 

8.AddDialog.java

public class AddDialog extends Dialog { private EditText mEditTextName,mEditTextAddress,mEditTextPhone; private Button mButtonAdd,mButtonCancel; private RadioGroup mRadioGroup; private int sex = 1;//性别 private Context mContext; private DialogListener mListener; public AddDialog(@NonNull Context context, DialogListener listener) { super(context); this.mContext = context; this.mListener = listener; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.add_dialog_layout); initView();          mRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { @Override public void onCheckedChanged(RadioGroup group, int checkedId) { switch (checkedId){ case R.id.add_radio_sex_boy:                         sex = 1; break; case R.id.add_radio_sex_girl:                         sex = 0; break; } } });          mButtonCancel.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { dismiss(); } });          mButtonAdd.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) {                 String name = mEditTextName.getText().toString();                 String address = mEditTextAddress.getText().toString();                 String phone = mEditTextPhone.getText().toString();                 User user = new User(name,phone,address,sex);                  UserDao.getUserDao(mContext).addUser(user);                  mListener.sendMessage(); dismiss(); } }); setCanceledOnTouchOutside(false); } //初始化界面 private void initView(){         mEditTextName = findViewById(R.id.edit_add_name);         mEditTextAddress = findViewById(R.id.edit_add_address);         mEditTextPhone = findViewById(R.id.edit_add_phone);          mButtonAdd = findViewById(R.id.button_add_add);         mButtonCancel = findViewById(R.id.button_add_cancel);          mRadioGroup = findViewById(R.id.add_radio_sex); } } 

9.AddDialog对应布局 add_dialog_layout.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="250dp" android:layout_height="400dp" android:background="#FDF5F5"> <RelativeLayout android:layout_width="match_parent" android:layout_height="80dp"> <TextView android:layout_centerInParent="true" android:textSize="20dp" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="添加联系人"/> </RelativeLayout> <View android:layout_width="match_parent" android:layout_height="1dp" android:background="#ccc" android:layout_marginLeft="10dp" android:layout_marginRight="10dp"/> <RelativeLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <LinearLayout android:layout_centerInParent="true" android:background="#E2E7FC" android:layout_width="180dp" android:layout_height="200dp" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="姓名:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <EditText android:id="@+id/edit_add_name" android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent" android:textSize="12dp" android:hint="请输入..."/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="性别:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <RadioGroup android:id="@+id/add_radio_sex" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:orientation="horizontal" > <RadioButton android:id="@+id/add_radio_sex_boy" android:layout_width="wrap_content" android:layout_height="wrap_content" android:checked="true" android:text="男" /> <RadioButton android:id="@+id/add_radio_sex_girl" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="女" /> </RadioGroup> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="电话:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <EditText android:id="@+id/edit_add_phone" android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent" android:textSize="12dp" android:hint="请输入..."/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="地址:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <EditText android:id="@+id/edit_add_address" android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent" android:textSize="12dp" android:hint="请输入..."/> </LinearLayout> </LinearLayout> </RelativeLayout> <View android:layout_width="match_parent" android:layout_height="1dp" android:background="#ccc" android:layout_marginLeft="10dp" android:layout_marginRight="10dp"/> <LinearLayout android:layout_width="match_parent" android:layout_height="50dp"> <Button android:id="@+id/button_add_add" android:textSize="12dp" android:layout_width="0dp" android:layout_gravity="center" android:layout_weight="3" android:layout_height="40dp" android:text="添加"/> <TextView android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent"/> <Button android:id="@+id/button_add_cancel" android:text="取消" android:layout_width="0dp" android:layout_weight="3" android:layout_height="40dp" android:layout_gravity="center" android:textSize="12dp"/> </LinearLayout> </LinearLayout> 

10. UpdateDialog.java

public class UpdateDialog extends Dialog { public User mUser;//弹框需要展示的信息 private EditText mEditTextName,mEditTextAddress,mEditTextPhone; private Button mButtonUpdate,mButtonDelete,mButtonCancel; private RadioGroup mRadioGroup; private int sex; private ImageView mImageView; private DialogListener mListener; private Context mContext; public UpdateDialog(@NonNull Context context,User user, DialogListener listener) { super(context); this.mUser = user; this.mContext = context; this.mListener = listener; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.update_dialog_layout); initView();          mRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { @Override public void onCheckedChanged(RadioGroup group, int checkedId) { switch (checkedId){ case R.id.update_radio_sex_boy:                         sex = 1; break; case R.id.update_radio_sex_girl:                         sex = 0; break; } } }); //删除按钮操作         mButtonDelete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) {                 UserDao.getUserDao(mContext).deleteUser(mUser);                 mListener.sendMessage(); dismiss(); } });          mButtonCancel.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { dismiss(); } });          mButtonUpdate.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //                tag = 2;                 String name = mEditTextName.getText().toString();                 String address = mEditTextAddress.getText().toString();                 String phone = mEditTextPhone.getText().toString();                 User user = new User(mUser.getId(),name,phone,address,sex);                 UserDao.getUserDao(mContext).updateUser(user);                 mListener.sendMessage(); dismiss(); } }); setCanceledOnTouchOutside(false); } //初始化界面 private void initView(){         mEditTextName = findViewById(R.id.edit_update_name);         mEditTextAddress = findViewById(R.id.edit_update_address);         mEditTextPhone = findViewById(R.id.edit_update_phone);         mButtonUpdate = findViewById(R.id.button_update_update);         mButtonCancel = findViewById(R.id.button_update_cancel);         mButtonDelete = findViewById(R.id.button_update_delete);         mRadioGroup = findViewById(R.id.update_radio_sex);         mImageView = findViewById(R.id.image_update);          sex = mUser.getSex(); //初始化内容         mRadioGroup.check(mUser.getSex()==1?R.id.update_radio_sex_boy:R.id.update_radio_sex_girl);         mEditTextName.setText(mUser.getName());         mEditTextPhone.setText(mUser.getPhone());         mEditTextAddress.setText(mUser.getAddress());         mImageView.setImageResource(mUser.getSex()==1?R.drawable.boy:R.drawable.girl); } } 

11. UpdateDialog对应布局 update_dialog_layout.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="250dp" android:layout_height="400dp" android:background="#FDF5F5"> <RelativeLayout android:layout_width="match_parent" android:layout_height="80dp"> <ImageView android:id="@+id/image_update" android:src="@drawable/girl" android:layout_centerInParent="true" android:layout_width="60dp" android:layout_height="60dp"/> </RelativeLayout> <View android:layout_width="match_parent" android:layout_height="1dp" android:background="#ccc" android:layout_marginLeft="10dp" android:layout_marginRight="10dp"/> <RelativeLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <LinearLayout android:layout_centerInParent="true" android:background="#E2E7FC" android:layout_width="180dp" android:layout_height="200dp" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="姓名:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <EditText android:id="@+id/edit_update_name" android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent" android:textSize="12dp"/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="性别:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <RadioGroup android:id="@+id/update_radio_sex" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:orientation="horizontal" > <RadioButton android:id="@+id/update_radio_sex_boy" android:layout_width="wrap_content" android:layout_height="wrap_content" android:checked="true" android:text="男" /> <RadioButton android:id="@+id/update_radio_sex_girl" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="女" /> </RadioGroup> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="电话:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <EditText android:id="@+id/edit_update_phone" android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent" android:textSize="12dp"/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:text="地址:" android:layout_marginLeft="10dp" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <EditText android:id="@+id/edit_update_address" android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent" android:textSize="12dp"/> </LinearLayout> </LinearLayout> </RelativeLayout> <View android:layout_width="match_parent" android:layout_height="1dp" android:background="#ccc" android:layout_marginLeft="10dp" android:layout_marginRight="10dp"/> <LinearLayout android:layout_width="match_parent" android:layout_height="50dp"> <Button android:id="@+id/button_update_delete" android:textSize="12dp" android:layout_width="0dp" android:layout_gravity="center" android:layout_weight="3" android:layout_height="40dp" android:text="删除"/> <TextView android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent"/> <Button android:id="@+id/button_update_update" android:layout_width="0dp" android:layout_weight="3" android:layout_height="40dp" android:layout_gravity="center" android:text="修改" android:textSize="12dp"/> <TextView android:layout_width="0dp" android:layout_weight="1" android:layout_height="match_parent"/> <Button android:id="@+id/button_update_cancel" android:text="取消" android:layout_width="0dp" android:layout_weight="3" android:layout_height="40dp" android:layout_gravity="center" android:textSize="12dp"/> </LinearLayout> </LinearLayout> 

12 DialogListener.java

public interface DialogListener { void sendMessage(); } 

13.MainActivity.java

public class MainActivity extends AppCompatActivity{ private Button mButtonAdd; private RecyclerView mRecyclerView; private UserAdapter mAdapter; private ArrayList<User> mUsers; private ImageView mImageView; private EditText mEditText; private DialogListener mListener = new DialogListener() { @Override public void sendMessage() {             mAdapter.updateView(); } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); getSupportActionBar().hide(); init(); initData();          mRecyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));         mAdapter = new UserAdapter(MainActivity.this,mUsers);         mRecyclerView.setAdapter(mAdapter);          mButtonAdd.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { new AddDialog(MainActivity.this,mListener).show(); } }); //点击查找         mImageView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) {                 String name = mEditText.getText().toString(); if (name.equals("")){                     Toast.makeText(MainActivity.this,"查询名字不允许为空",Toast.LENGTH_SHORT).show(); }else {                     User user = UserDao.getUserDao(MainActivity.this).getUserByName(name);                     UpdateDialog dialog = new UpdateDialog(MainActivity.this,user,mListener);                     dialog.show(); } } }); } private void init(){         mButtonAdd = findViewById(R.id.main_button_add);         mRecyclerView = findViewById(R.id.main_recycler_view);         mEditText = findViewById(R.id.main_edit_name);         mImageView = findViewById(R.id.main_image_find); } void initData(){         mUsers = UserDao.getUserDao(MainActivity.this).getAllUser(); } } 

14.主布局文件activity_main.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="60dp"> <EditText android:id="@+id/main_edit_name" android:layout_gravity="bottom" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="3" android:hint="请输入需要查询的名字" android:layout_marginLeft="20dp" android:layout_marginRight="10dp"/> <RelativeLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1"> <ImageView android:id="@+id/main_image_find" android:src="@drawable/find" android:layout_width="35dp" android:layout_height="35dp" android:layout_centerInParent="true"/> </RelativeLayout> </LinearLayout> <androidx.recyclerview.widget.RecyclerView android:id="@+id/main_recycler_view" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"/> <Button android:id="@+id/main_button_add" android:layout_width="match_parent" android:layout_height="40dp" android:text="添加联系人"/> </LinearLayout> 

15.子布局文件 info_item.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="https://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="100dp"> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <RelativeLayout android:background="#F8F4D3" android:layout_width="80dp" android:layout_height="match_parent"> <ImageView android:id="@+id/info_image" android:layout_centerInParent="true" android:src="@drawable/girl" android:layout_width="60dp" android:layout_height="60dp"/> </RelativeLayout> <LinearLayout android:layout_width="0dp" android:layout_weight="1" android:background="#E1F5EC" android:layout_height="match_parent" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="2"> <TextView android:id="@+id/info_name" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_marginLeft="10dp" android:text="大青儿" android:textSize="25dp" android:textColor="#333"/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"> <TextView android:id="@+id/info_phone" android:layout_gravity="center" android:text="电话:13222240503" android:layout_marginLeft="10dp" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/info_address" android:layout_gravity="center" android:text="地址:江苏苏州" android:layout_marginLeft="10dp" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </LinearLayout> </LinearLayout> </LinearLayout> <View android:layout_width="match_parent" android:layout_height="1dp" android:background="#666"/> </LinearLayout> 

总结

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