android studio简单的密码日记本，实现增删改查功能

待我称王封你为后i 2022-01-05 08:29 1199阅读 0赞

# 简单的记事本 #

##### 软件名字：一本日记 #####

##### 软件功能 ：简单的密码日记本，实现增删改查功能 #####

##### 软件的使用知识点： #####

布局方面：线性布局，相对布局

控件方面：常见控件,List View, Navigation View(滑动菜单),FloatingActionButton （悬浮按钮）

后台方面：主要是Adapter和Sq Lite,Intent

##### 项目的结构如下图： #####

\[外链图片转存失败(img-OocaH9L5-1563628277567)(C:\\Users\\weng\\Desktop\\安卓期末1.png)\]![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70]

##### 分析软件的组成： #####

##### 展示核心的代码 #####

###### 1，登录 ######

<EditText
                 	android:id="@+id/edt_username"------请输入昵称
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="5dp"
                  android:inputType="text"
                  android:hint="请输入昵称"
                  android:padding="5dp"/>
         	 <EditText
              android:id="@+id/edt_password"----------密 码
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginLeft="5dp"
              android:inputType="textPassword"
              android:hint="请输入密码"
              android:padding="5dp"/>
        	<Button
              android:id="@+id/btn_login"----------登录
              android:layout_below="@+id/line_password"
              android:layout_width="80dp"
              android:layout_marginTop="40dp"
              android:layout_marginLeft="60dp"
              android:text="登 录"
              android:background="@android:color/white"
              android:textSize="24sp"
              android:layout_height="60dp" />
          <Button
              android:id="@+id/btn_go_register"----------注册
              android:layout_below="@+id/line_password"
              android:layout_toRightOf="@+id/btn_login"
              android:layout_width="80dp"
              android:layout_marginTop="40dp"
              android:layout_marginLeft="80dp"
              android:text="注 册"
              android:background="@android:color/white"
              android:textSize="24sp"
              android:layout_height="60dp" />
      
      
     
    
    登录的业务逻辑：
    
    ```java
    public class LoginActivity extends AppCompatActivity {
        public static int userID;
        public static String username;
        String name, password;//保存数据
        private EditText edt_username;//用户名字
        private EditText edt_password;//用户密码
        private Button btn_login;
        private Button btn_register;
        //private SQLiteDatabase sqlDate;
        private MyDB myDB;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);//隐藏状态栏
            getSupportActionBar().hide();//隐藏标题栏
            setContentView(R.layout.activity_main);
            initUI();
            myDB = new MyDB(this);//创建对象
            //注册
            btn_register.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Intent intent = new Intent(LoginActivity.this, RegistActivity.class);
                    startActivityForResult(intent,1);
                }
            });
            //登入
            btn_login.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    name = edt_username.getText().toString();
                    password = edt_password.getText().toString();
                    if (enter(name, password)) {
                        Toast.makeText(LoginActivity.this, "登录成功" + name, Toast.LENGTH_SHORT).show();
                        new Thread(){
                            public void run() {
                                try {
                                    Thread.sleep(1000);
                                    Intent intent1 = new Intent(LoginActivity.this, IndexActivity.class);
                                    startActivity(intent1);
                                } catch (Exception e) {
                                    e.printStackTrace();
                                }
                            }
                        }.start();
                    } else if (TextUtils.isEmpty(name) || TextUtils.isEmpty(password) || TextUtils.isEmpty(name) && TextUtils.isEmpty(password)) {
                        Toast.makeText(LoginActivity.this, "请输入用户名或密码", Toast.LENGTH_SHORT).show();
                    } else {
                        Toast.makeText(LoginActivity.this, "登入失败", Toast.LENGTH_SHORT).show();
                    }
                }
            });
        }
    
        /**
         * 初始化：initUI()
         */
        private void initUI() {
            edt_username = (EditText) findViewById(R.id.edt_username);
            edt_password = (EditText) findViewById(R.id.edt_password);
            btn_login = (Button) findViewById(R.id.btn_login);
            btn_register = (Button) findViewById(R.id.btn_go_register);
        }
        /**
         * 判断是否username,password 和数据库的相同 enter()
         */
        public boolean enter(String name, String password) {
            SQLiteDatabase db = myDB.getWritableDatabase();
            String sql = "select user_id from tb_user where username=? and password=?";
            Cursor cursor = db.rawQuery(sql, new String[]{name, password});
            if (cursor.getCount() != 0) {//返回Cursor 中的行数
                if (cursor.moveToNext()) {
                    userID = cursor.getInt(cursor.getColumnIndex("user_id"));
                    username = name;
                }
                cursor.close();
                return true;
            }
            return false;
        }
        /**
         * 数据回显
         * @param requestCode
         * @param resultCode
         * @param data
         */
        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (requestCode==1 && resultCode==1){
                String name=data.getStringExtra("name");
                String password=data.getStringExtra("password");
                edt_username.setText(name);
                edt_password.setText(password);
            }
        }
    }

2注册

注册的业务逻辑：

public class RegistActivity extends AppCompatActivity { 
        private EditText edt_setname;
        private EditText edt_setpassword;
        private  EditText edt_confirm_password;
        private Button btn_register;
        String name,password,id;
        private MyDB myDB;
        ContentValues contentValues=new ContentValues();
        @Override
        protected void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState);
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);//隐藏状态栏
            getSupportActionBar().hide();//隐藏标题栏*/
            setContentView(R.layout.activity_regist);
            initUI();
            myDB=new MyDB(this);
            btn_register.setOnClickListener(new View.OnClickListener() { 
                @Override
                public void onClick(View view) { 
                    SQLiteDatabase db=myDB.getWritableDatabase();
                    name = edt_setname.getText().toString();
                    password = edt_setpassword.getText().toString();
                    if (edt_setname.getText().toString().contains(" ") || edt_setpassword.getText().toString().contains(" ")) { 
                        Toast.makeText(RegistActivity.this, "输入的用户名或密码不能包含空格", Toast.LENGTH_SHORT).show();
                        return;
                    }
                    else if(edt_setpassword.getText().toString().length()==0||edt_setname.getText().toString().length()==0){ 
                        Toast.makeText(RegistActivity.this, "请输入用户名或密码", Toast.LENGTH_SHORT).show();
                        return;
                    }
                    else if(!edt_confirm_password.getText().toString().equals(edt_setpassword.getText().toString())){ 
                        Toast.makeText(RegistActivity.this, "两次密码不一致，请确认再注册", Toast.LENGTH_SHORT).show();
                        return;
                    }
                    if(login(name)){ 
                        Toast.makeText(RegistActivity.this, "该用户名已注册", Toast.LENGTH_SHORT).show();
                        return;
                    }
                    contentValues.put("username", name);
                    contentValues.put("password", password);
                    db.insert("tb_user", null, contentValues);
                    String sql="select user_id from tb_user where username=? and password=?";
                    Cursor cursor = db.rawQuery(sql, new String[] { name, password});
                    if(cursor.moveToNext()){ //id
                        id=Integer.toString(cursor.getInt(0));//防止数据库的值null和0 分不清
                    }
                    cursor.close();
                    db.close();
                    Toast.makeText(RegistActivity.this, "注册成功", Toast.LENGTH_SHORT).show();
                    new Thread(){ 
                        @Override
                        public void run() { 
                            super.run();
                            try { 
                                Thread.sleep(1000);
                                Intent intent = new Intent(RegistActivity.this,LoginActivity.class);
                                intent.putExtra("name",edt_setname.getText().toString());
                                intent.putExtra("password",edt_setpassword.getText().toString());
                                setResult(1, intent);//返回页面1
                                finish();
                              // startActivity(intent);
                            } catch (InterruptedException e) { 
                                e.printStackTrace();
                            }
                        }
                    }.start();
                }
            });
        }
    
        /** * 初始化View :initUI() */
        public void initUI(){ 
            edt_setname=(EditText)findViewById(R.id.edt_setusername);
            edt_setpassword=(EditText)findViewById(R.id.edt_setpassword);
            edt_confirm_password=(EditText)findViewById(R.id.edt_confirm_password);
            btn_register=(Button)findViewById(R.id.btn_register);
        }
        /** * 查询数据库是否有重复的 * 进行数据的查询 login() */
        public boolean login(String name){ 
            SQLiteDatabase db=myDB.getWritableDatabase();
            String sql="select * from tb_user where username=?";
            Cursor cursor=db.rawQuery(sql,new String[]{ name});
            if (cursor.getCount()!=0){ 
                cursor.close();
                return true;
            }
            return false;
        }
    }

3主页面

主页面的业务逻辑:

public class IndexActivity extends AppCompatActivity { 
        List<Note> mList;
        private FloatingActionButton fdb;
        private NavigationView navigationView;
        private ListView listView;
        private MyAdapter myAdapter;
        private MyDB myDB;
        private Cursor cursor;
        private SQLiteDatabase dbreader;;
        @Override
        protected void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState);
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);//隐藏状态栏
            getSupportActionBar().hide();//隐藏标题栏
            setContentView(R.layout.activity_test);
            listView = (ListView) findViewById(R.id.list);
            navigationView = (NavigationView) findViewById(R.id.navigat);
            View view1 = navigationView.getHeaderView(0);//通过nav来查询head文件
            TextView wc = view1.findViewById(R.id.welcome);
            myDB = new MyDB(this);
            dbreader = myDB.getReadableDatabase();
            wc.setText("欢迎你:" + LoginActivity.username);
            Toast.makeText(IndexActivity.this, "登录成功，欢迎回来！", Toast.LENGTH_SHORT).show();
            listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
                @Override
                public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) { 
                    Intent intent = new Intent(IndexActivity.this, showActivity.class);
                    intent.putExtra("ID", mList.get(position).getId());
                    intent.putExtra("content", mList.get(position).getContent());
                    intent.putExtra("time", mList.get(position).getTime());
                    startActivity(intent);
            }
            });
            fdb = (FloatingActionButton) findViewById(R.id.floactAdd);
            fdb.setOnClickListener(new View.OnClickListener() { 
                @Override
                public void onClick(View view) { 
                    Intent intent = new Intent(IndexActivity.this, AddContentActivity.class);
                    startActivity(intent);
                }
            });
            navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() { 
                @Override
                public boolean onNavigationItemSelected(@NonNull MenuItem item) { 
                    switch (item.getItemId()){ 
                        case R.id.prsetposs:
                            Intent intent1=new Intent(IndexActivity.this,setpasswordActivity.class);
                            intent1.putExtra("username",LoginActivity.username);
                            startActivity(intent1);
                            break;
                        case R.id.showtime:
                            Toast.makeText(IndexActivity.this,AddContentActivity.getTime(),Toast.LENGTH_LONG).show();
                            break;
                        case R.id.prsize:
                            Toast.makeText(IndexActivity.this,IndexActivity.this.allDBNum() + "个用户使用了软件",Toast.LENGTH_LONG).show();
                            break;
                        case  R.id.success:
                            Intent intent=new Intent(IndexActivity.this,LoginActivity.class);
                            Toast.makeText(IndexActivity.this,"退出成功",Toast.LENGTH_LONG).show();
                            startActivity(intent);
                    }
                    return true;
                }
            });
        }
        public void selectDb() { 
            mList = new ArrayList<>();
            cursor = dbreader.rawQuery("SELECT * FROM tb_note WHERE userID = ?", new String[]{ LoginActivity.userID + ""});
            while (cursor.moveToNext()) { 
                Note note = new Note();
                int id = cursor.getInt(cursor.getColumnIndex("ID"));
                String time = cursor.getString(cursor.getColumnIndex("time"));
                String content = cursor.getString(cursor.getColumnIndex("content"));
                note.setTime(time);
                note.setContent(content);
                note.setId(id);
                mList.add(note);
            }
            cursor.close();
            myAdapter = new MyAdapter(this, mList);
            listView.setAdapter(myAdapter);
        }
    
        @Override
        protected void onResume() { 
            super.onResume();
            selectDb();
        }
        /** *查询用户的个数 allDBNum() */
        public int allDBNum( ){ 
            String sql = "select count(*) count from tb_user";
            Cursor cursor = dbreader.rawQuery(sql, null);
             cursor.moveToFirst();
            int count= cursor.getInt(0);
            if (cursor.getCount()!=0){ 
                cursor.close();
            }
            return count;
        }
    }

4 List View 布局：

5List View适配器:

public class MyAdapter extends BaseAdapter { 
        private Context mContext;
        private List<Note> mList;
        private LinearLayout mlayout;
    
        public MyAdapter(Context mContext, List<Note> mList){ 
            this.mContext=mContext;
            this.mList=mList;
        }
        @Override
        public int getCount() { 
            return mList.size();
        }
        @Override
        public Object getItem(int position) { 
            return mList.get(position);
        }
        @Override
        public long getItemId(int position) { 
            return position;
        }
        @Override
        public View getView(int position, View convertView, ViewGroup parent) { 
            LayoutInflater inflater = LayoutInflater.from(mContext);
            mlayout=(LinearLayout) inflater.inflate(R.layout.listre,null);
            TextView content=(TextView)mlayout.findViewById(R.id.list_content);
            TextView time=(TextView)mlayout.findViewById(R.id.list_time);
            content.setText(mList.get(position).getContent());
            time.setText(mList.get(position).getTime());
            return mlayout;
        }
    }

6数据库文件:

ublic class MyDB extends SQLiteOpenHelper{
        //用户表
        public static  final  String CREATE_USER="create table tb_user(" +
                "user_id integer primary key autoincrement," +
                "username varchar(50)," +
                "password varchar(50))";
        //
        public static final String CREATE_NOTE="create table tb_note("+
                "ID integer primary key AUTOINCREMENT,"+
                "content TEXT NOT NULL,"+
                "userID  integer,"+
                "time TEXT NOT NULL)";
        //上下文
        private  Context mcontext;
        public static final  String CREATE_NOTES="";
        public MyDB(Context context) {
            super(context, "MyDB.db", null, 2);
            mcontext=context;
        }
    
        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(CREATE_USER);
            db.execSQL(CREATE_NOTE);
            Toast.makeText(mcontext,"创建成功！",Toast.LENGTH_SHORT).show();
        }
        @Override
        public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
            
        }
    }

7Note的实体类：

public class Note { 
        private Integer id;
        private Integer userID;
        private String content;
        private String time;
    
        public Integer getId() { 
            return id;
        }
    
        public void setId(Integer id) { 
            this.id = id;
        }
    
        public Integer getUserID() { 
            return userID;
        }
    
        public void setUserID(Integer userID) { 
            this.userID = userID;
        }
    
        public String getContent() { 
            return content;
        }
    
        public void setContent(String content) { 
            this.content = content;
        }
    
        public String getTime() { 
            return time;
        }
    
        public void setTime(String time) { 
            this.time = time;
        }
    }

8添加内容的页面：

添加内容的业务逻辑：

private EditText met;
    private MyDB myDB;
    private SQLiteDatabase mysqldb;
    @Override
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState);
      getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);//隐藏状态栏
        getSupportActionBar().hide();//隐藏标题栏
        setContentView(R.layout.activity_add_content);
        met=(EditText)findViewById(R.id.text);
        myDB=new MyDB(this);
        mysqldb=myDB.getWritableDatabase();
    }
    public void save(View v) { 
        DdAdd();
        finish();
    }
    public void cancle(View v) { 
        met.setText("");
        finish();
    }
    public void DdAdd(){ 
        ContentValues cv = new ContentValues();
        cv.put("content",met.getText().toString());
        cv.put("time",getTime());
        cv.put("userID", LoginActivity.userID);
        mysqldb.insert("tb_note",null,cv);//插入数据
    }
    public static String getTime(){ 
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
        Date date=new Date();
        String str=sdf.format(date);
        return str;
    }

9显示内容的页面：

显示页面的业务逻辑：

public class showActivity extends AppCompatActivity { 
        private EditText mtext;
        private TextView time;
        private MyDB myDB;
        private SQLiteDatabase msql;
        @Override
        protected void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState);
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);//隐藏状态栏
            getSupportActionBar().hide();//隐藏标题栏
            setContentView(R.layout.activity_show);
            mtext=(EditText) findViewById(R.id.showtext);
            time=(TextView)findViewById(R.id.showtime);
            myDB=new MyDB(this);
            msql=myDB.getWritableDatabase();
            mtext.setInputType(InputType.TYPE_CLASS_TEXT);//开启可以编写
            mtext.setText(getIntent().getStringExtra("content"));
            time.setText(getIntent().getStringExtra("time"));
        }
        /** * 删除 delete * @param v */
        public void delete(View v) { 
              int id = getIntent().getIntExtra("ID",0);
              msql.delete("tb_note","ID = " + id,null);
              finish();
              /** * 修改 update */
        }public void update(View v){ 
            int id = getIntent().getIntExtra("ID",0);
            String content=mtext.getText().toString();
            msql.execSQL("UPDATE tb_note SET content=? WHERE ID = ?",
                    new String[]{ content,id+""});
            finish();
        }
        /** * 关闭 * @param v */
        public void goBack(View v) { 
            finish();
        }
    
    }

10修改密码的页面：

修改密码的业务逻辑：

public class setpasswordActivity extends AppCompatActivity { 
        private EditText setpass;
        private MyDB myDB;
        private SQLiteDatabase msql;
        @Override
        protected void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState);
           getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);//隐藏状态栏
            getSupportActionBar().hide();
            setContentView(R.layout.activity_setpassword);
            myDB=new MyDB(this);
            msql=myDB.getWritableDatabase();
            setpass=(EditText)findViewById(R.id.setpass);
    
        }
        public  void yes(View v){ 
            String username = getIntent().getStringExtra("username");
            String pass=setpass.getText().toString();
            msql.execSQL("UPDATE tb_user SET password=? WHERE username=?",
                    new String[]{ pass,username});
            Toast.makeText(setpasswordActivity.this, "密码修改完了，请记住现在的密码", Toast.LENGTH_SHORT).show();
            Intent intent2=new Intent(setpasswordActivity.this,LoginActivity.class);
            startActivity(intent2);
            finish();
        }
        public void no(View v){ 
            Intent intent=new Intent(setpasswordActivity.this,IndexActivity.class);
            startActivity(intent);
            finish();
        }
    }

#### 软件的展示图片： ####

登录：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 1]  
注册：

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 2]  
主页面  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 3]  
主页面2  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 4]  
添加  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 5]  
修改  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 6]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70]: /images/20211229/a5e6b8c9dd6c4451b368c3230baeb727.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 1]: /images/20211229/37349310eab04e42ab525c861dbdbf33.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 2]: /images/20211229/f448b99fa8d54b7fb2ab183eed0e3276.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 3]: /images/20211229/d9489fcb44fd40c4a03567edb47941f7.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 4]: /images/20211229/b31726f5b2b94dc98a82acf87425ea17.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 5]: /images/20211229/1b6688f1e56a45f9929f68c1e9932a71.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlbmc3NA_size_16_color_FFFFFF_t_70 6]: /images/20211229/a7b84e75a0dc4f10b34e98cbb1795122.png