登录后在 textview 中显示 SQLite 数据

Posted 2023-03-15

【中文标题】登录后在 textview 中显示 SQLite 数据

【英文标题】：Display SQLite data in textview after login

【发布时间】：2018-04-30 22:58:12

【问题描述】：

我有一个登录活动、注册活动和个人资料活动。按下登录按钮后，我可以在个人资料活动中显示我的用户名，这是登录后的第三次活动。但是，我无法将名字、姓氏、GRE、托福从数据库显示到个人资料活动。 vl 我如何在个人资料活动的文本视图中查看每个用户的名字、姓氏、gre 和 toefl。

这是我的代码：

这是 SQLiteDB ProfileDatabase.class

public class ProfileDatabaseHelper extends SQLiteOpenHelper 

private static final int DATABASE_VERSION= 1;
private static final String DATABASE_NAME="profiles.db";
private static final String TABLE_NAME="profile";

private static final String COLUMN_PROFID="profId";
private static final String COLUMN_FNAME="firstName";
private static final String COLUMN_LNAME="lastName";
private static final String COLUMN_UNAME="userName";
private static final String COLUMN_PASS="pass";
private static final String COLUMN_GRE= "gre";
private static final String COLUMN_TOEFL= "toefl";
SQLiteDatabase db;

private static final String TABLE_CREATE = "create table profile (profId integer primary key  not null," +
        " firstName text not null, lastName text not null, userName text not null, pass text not null, gre integer not null, toefl integer not null);";

public ProfileDatabaseHelper(Context context) 
    super(context,DATABASE_NAME, null, DATABASE_VERSION);


@Override
public void onCreate(SQLiteDatabase db) 
    db.execSQL(TABLE_CREATE);
    this.db=db;



public void insertProfile(ProfileList pl)

    db = this.getWritableDatabase();
    ContentValues values = new ContentValues();

    String query = "Select * from profile";
    Cursor cursor = db.rawQuery(query, null);
    int count = cursor.getCount();
    values.put(COLUMN_PROFID,count);
    values.put(COLUMN_FNAME,pl.getFName());
    values.put(COLUMN_LNAME,pl.getLName());
    values.put(COLUMN_UNAME,pl.getUName());
    values.put(COLUMN_PASS,pl.getPass());
    values.put(COLUMN_GRE,pl.getGre());
    values.put(COLUMN_TOEFL,pl.getToefl());

    db.insert(TABLE_NAME, null,values);
    db.close();




public String searchPass(String uname)
    db = this.getReadableDatabase();
    String query = "select username, pass from "+TABLE_NAME;
    Cursor cursor = db.rawQuery(query, null);
    String a, b;
    b = "Not found";
    if(cursor.moveToFirst())
        do
            a = cursor.getString(0);
            if(a.equals(uname))
                b = cursor.getString(1);
                break;
            


        
        while(cursor.moveToNext());
    
    return b;




@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) 
    String query = "DROP TABLE IF EXISTS "+TABLE_NAME;
    db.execSQL(query);

  

这是我的 login.class

public class LoginUser extends AppCompatActivity 

ProfileDatabaseHelper helper = new ProfileDatabaseHelper(this);
@Override
protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login_user);




public void onBtnClick(View v)
    if (v.getId() == R.id.loginButton)

        EditText loginName = (EditText)findViewById(R.id.loginUserName);
        String loginNameStr = loginName.getText().toString();

        EditText password = (EditText)findViewById(R.id.loginPass);
        String pass = password.getText().toString();

        String passwordLogin = helper.searchPass(loginNameStr);


        if(pass.equals(passwordLogin))


            Intent i = new Intent(LoginUser.this, ProfileUser.class);
            i.putExtra("Username", loginNameStr);
            startActivity(i);
        

        else 
            Toast.makeText(LoginUser.this,"Username and Password don't match",Toast.LENGTH_LONG).show();
        


    
    if (v.getId() == R.id.signUpButton)
        Intent i = new Intent(LoginUser.this, RegisterUser.class);
        startActivity(i);
    

这是显示用户个人资料的第三个活动

public class ProfileUser extends AppCompatActivity 

ProfileDatabaseHelper db;
@Override
protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_profile_user);



    String username = getIntent().getStringExtra("Username");
    TextView userText = (TextView)findViewById(R.id.userNameDisplayText);
    userText.setText(username);

    //How canI enter each person personal first name, last name, grey and 
     toefl


    TextView userText = (TextView)findViewById(R.id.userNameDisplayText);
    TextView userText = (TextView)findViewById(R.id.userNameDisplayText);
    TextView userText = (TextView)findViewById(R.id.userNameDisplayText);
    TextView userText = (TextView)findViewById(R.id.userNameDisplayText);



  
 

【参考方案1】：

您需要编辑您的searchPass(username, password) 方法，使其在username 和password 匹配时返回完整的User 对象，然后在您的IF 条件User user = helper.searchPass(loginNameStr, password); 之前调用此方法

现在您有了包含所有用户详细信息的 user 对象，您需要在检查密码后发送其他内容，如下所示。

if(user.getPassword().equals(passwordLogin))
    Intent i = new Intent(LoginUser.this, ProfileUser.class);
    i.putExtra("Username", user.getUsername());
    i.putExtra("firstName", user.getFirstName());
    i.putExtra("lastName", user.getLastName());
    i.putExtra("gre", user.getGre());
    i.putExtra("toefl", user.getToefl());
    startActivity(i);

然后在您的ProfileUser 活动中从intent 检索详细信息，如下所示

String username = getIntent().getStringExtra("Username");
String firstName = getIntent().getStringExtra("firstName");
String lastName = getIntent().getStringExtra("lastName");
String gre = getIntent().getStringExtra("gre");
String toefl = getIntent().getStringExtra("toefl");

【讨论】：

如何在 searchPass 中返回用户对象。

嘿，我尝试添加返回对象，但在 null 对象引用上出现 user.getPassword() 错误。

您应该首先在 model 类中添加该字段，并确保在对象中设置其 value。