详解Android数据存储—使用SQLite数据库(2)-木庄网络博客

3.注册界面

public class RegisterActivity extends Activity {
  String name;
  String pass;
  String age;
  SQLiteDatabase db;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // TODO 自动生成的方法存根
    super.onCreate(savedInstanceState);
    setContentView(R.layout.register);
    final EditText et_userName=(EditText)findViewById(R.id.editText_1);
    final EditText et_password=(EditText)findViewById(R.id.editText_2);
    final EditText et_age=(EditText)findViewById(R.id.editText_3);
    Button btn_confirm=(Button)findViewById(R.id.register_confirm);
    btn_confirm.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        // TODO 自动生成的方法存根
        name=et_userName.getText().toString();
        pass=et_password.getText().toString();
        age=et_age.getText().toString();
        //得到数据库对象

        DatabaseHelper helper=new DatabaseHelper(getBaseContext());
        db=helper.getWritableDatabase();
        //判断用户名是否已存在
        Cursor cursor=db.query(DatabaseHelper.TABLENAME, new String[]{DatabaseHelper.NAME},
            DatabaseHelper.NAME+"=?", new String[]{name}, null, null, null);
        //若查询目标已存在
        if(cursor.getCount()>0){
          Toast.makeText(getBaseContext(), "用户名已存在", Toast.LENGTH_SHORT).show();
          return;
        }

      //若不存在，则插入数据

      ContentValues values=new ContentValues();
      values.put(DatabaseHelper.NAME, name);
      values.put(DatabaseHelper.PASSWORD, pass);
      values.put(DatabaseHelper.AGE, age);
      db.insert(DatabaseHelper.TABLENAME, null, values);
      //进行跳转
      Intent intent=new Intent(RegisterActivity.this, MainActivity.class);
      intent.putExtra("NAME", name);
      startActivity(intent);
      }
    });
  }
}

4.登录成功界面

public class MainActivity extends Activity {
  String name;
  String pass;
  String age;

   private Button logout;
   SQLiteDatabase db;
   private SharedPreferences sharedPreferences;  
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  //  MyApplication.getInstance().addActivity(this); 
    setContentView(R.layout.main_activity);
    logout=(Button) findViewById(R.id.logout);
    doQuery();//进行查询
    doShow();//进行显示
    logout.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        // TODO 自动生成的方法存根
        removeSharedPreference();
       Intent intent=new Intent();
       intent.setClass(MainActivity.this, LoginActivity.class);
       startActivity(intent);
      }
    });
  }

  private void doQuery() {
    // TODO 自动生成的方法存根
    name=getIntent().getExtras().getString("NAME");
    DatabaseHelper helper=new DatabaseHelper(getBaseContext());
    db=helper.getReadableDatabase();
    //准备查询de属性
    String[] columns=new String[]{DatabaseHelper.PASSWORD,DatabaseHelper.AGE};
    Cursor cursor=db.query(DatabaseHelper.TABLENAME, columns, DatabaseHelper.NAME+"=?", 
        new String[]{name}, null, null, null);
    cursor.moveToFirst();
    while(!cursor.isAfterLast()){//判断是否是最后一条记录
      pass=cursor.getString(0);
       age=cursor.getString(1);
      cursor.moveToNext();
    }
  }
  private void doShow() {
    // TODO 自动生成的方法存根
    TextView tv_show=(TextView)findViewById(R.id.show1);
    tv_show.setText("用户信息如下：\n"+"账户："+name+"\n密码"+pass+"\n年龄"+age);
  }
  public void removeSharedPreference() {
    sharedPreferences = getSharedPreferences("userInfo", Context.MODE_PRIVATE);
    Editor editor = sharedPreferences.edit();
    //editor.remove("userName");
    editor.remove("AUTO_ISCHECK");
    editor.commit();// 提交修改
    }
}

标签：SQLite

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