Question

DBHandle

public class DBHandler extends SQLiteOpenHelper {



public DBHandler(Context context) {
        super(context, UserProfile.Users.DATABASE_NAME, null, 1);
}

@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {

         String createTable = "CREATE TABLE "+UserProfile.Users.TABLE_NAME+"("+ UserProfile.Users.COL_1+" INTEGER PRIMARY KEY AUTOINCREMENT,"+UserProfile.Users.COL_2+" TEXT, "+ UserProfile.Users.COL_3 +" TEXT, "+ UserProfile.Users.COL_4 +" TEXT, "+ UserProfile.Users.COL_5+" TEXT "+")";

         sqLiteDatabase.execSQL(createTable);

}

@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

        sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " + UserProfile.Users.TABLE_NAME);

}


public boolean addInfo(UserProfile.Users users){

        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues cv = new ContentValues();
        cv.put(UserProfile.Users.COL_2,users.getUserName());
        cv.put(UserProfile.Users.COL_3,users.getDateOfBirth());
        cv.put(UserProfile.Users.COL_4,users.getPassword());
        cv.put(UserProfile.Users.COL_5,users.getGender());
        long result = db.insert(UserProfile.Users.TABLE_NAME,null,cv);

        if(result == -1){

            return false;
        }
        else
            return true;

}



public boolean updateData(UserProfile.Users users){

        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues cv = new ContentValues();
        //cv.put(UserProfile.Users.COL_1,users.getID());
        cv.put(UserProfile.Users.COL_2,users.getUserName());
        cv.put(UserProfile.Users.COL_3,users.getDateOfBirth());
        cv.put(UserProfile.Users.COL_4,users.getPassword());
        cv.put(UserProfile.Users.COL_5,users.getGender());

        db.update(UserProfile.Users.TABLE_NAME,cv,"username= ?",new String[]{users.getUserName()});
        return true;
}



public Cursor readAllInfor(){

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor res = db.rawQuery("select * from "+UserProfile.Users.TABLE_NAME,null);
        return  res;
}

public int deleteData(UserProfile.Users user){

        SQLiteDatabase db = this.getWritableDatabase();
        return db.delete(UserProfile.Users.TABLE_NAME,"username= ?",new String[]{user.getUserName()});


}




}

个人资料

public class ProfileManagement extends AppCompatActivity {

DBHandler mydb;
EditText username1,password1,dob;
Button save;
RadioGroup radioGroup1;
RadioButton radioButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_profile_management);
    mydb  = new DBHandler(this);
    username1 = (EditText)findViewById(R.id.username);
    password1 = (EditText)findViewById(R.id.password);
    dob = (EditText)findViewById(R.id.dateOfBirth);
    save = (Button)findViewById(R.id.update);

    radioGroup1 = (RadioGroup)findViewById(R.id.radioGroup);

    addData();

}


public void addData(){


    save.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            int selectedID = radioGroup1.getCheckedRadioButtonId();

            if (selectedID == 0) {

                Toast.makeText(ProfileManagement.this, "cannot be empty", Toast.LENGTH_SHORT).show();
            } else {
                radioButton = (RadioButton) findViewById(selectedID);
                String username = username1.getText().toString();
                String password = password1.getText().toString();

                String dateOfBirth = dob.getText().toString();
                String radio = radioButton.getText().toString();
                UserProfile.Users users = UserProfile.getProfile().getUsers();


                users.setUsername(username);
                users.setDob(dateOfBirth);
                users.setPassword(password);
                users.setGender(radio);


                boolean isInserted = mydb.addInfo(users);

                if (isInserted == true) {

                    Toast.makeText(ProfileManagement.this, "Data Inserted", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(ProfileManagement.this, "Error", Toast.LENGTH_SHORT).show();
                }

            }
        }
    });


}



}

用户

package com.google.hangout.it17092548_mad;

import android.provider.BaseColumns;

public class UserProfile {

private UserProfile(){
}

public static UserProfile getProfile(){

    UserProfile userProfile = new UserProfile();
    return userProfile;
}

public class Users implements BaseColumn{

    public static final String DATABASE_NAME = "database.db";
    public static final String TABLE_NAME = "user_table";
    public static final String COL_1 ="ID";
    public static final String COL_2="username";
    public static final String COL_3 = "dateofbirth";
    public static final String COL_4 = "password";
    public static final String COL_5 = "gender";

    private int ID;
    private String userName;
    private String dateOfBirth;
    private String password;
    private String gender;

    public String getPassword() {
        return password;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setID(int ID) {
        this.ID = ID;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public void setDateOfBirth(String dateOfBirth) {
        this.dateOfBirth = dateOfBirth;
    }

    public int getID() {
        return ID;
    }

    public String getUserName() {
        return userName;
    }

    public String getDateOfBirth() {
        return dateOfBirth;
    }
}

public Users getUser(){
    Users users = new Users();

    return users;
}
}

家

public class Home extends AppCompatActivity {

DBHandler mydb;
Button reg,log;
EditText username,password;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    mydb = new DBHandler(this);
    username = (EditText)findViewById(R.id.username);
    password = (EditText)findViewById(R.id.password);

    reg = findViewById(R.id.register);
    log = findViewById(R.id.login);
    reg.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent t1 = new Intent(Home.this,ProfileManagement.class);
            startActivity(t1);

        }
    });

    log.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

           /* if(username.equals("") || username == null){
                Toast.makeText(getApplicationContext(), "Username Empty",
                        Toast.LENGTH_SHORT).show();
            }
            else if(password.equals("") || password == null){
                Toast.makeText(getApplicationContext(), "Password Empty",
                        Toast.LENGTH_SHORT).show();
            }


            Cursor c = db.rawQuery("SELECT email FROM MY_USERS_TABLE WHERE email= ? AND password=?", new String[] {username, password});
            if(c.moveToFirst()) {
                Toast.makeText(getApplicationContext(), "Success", Toast.LENGTH_SHORT).show();
                Intent main = new Intent(Home.this, EditProfile.class);
                startActivity(main);
            }
            else {
                Toast.makeText(getApplicationContext(), "Failed..\nTry Again", Toast.LENGTH_SHORT).show();

            }*/


        }
    });



}
}

编辑

public class EditProfile extends Activity {

    DBHandler myDb;
    Button viewDetails;
    Button dele,update;
    EditText username1,DofB,password;
    RadioGroup radioGroup;
    RadioButton genderRadioButton;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_edit_profile);
                myDb = new DBHandler(this);
                viewDetails = (Button)findViewById(R.id.search);
                dele = (Button)findViewById(R.id.delete);
                username1 = (EditText)findViewById(R.id.username);
                DofB = (EditText)findViewById(R.id.dateOfBirth);
                password = (EditText)findViewById(R.id.password);
                radioGroup = (RadioGroup)findViewById(R.id.radioBtnGroup);
                update = (Button)findViewById(R.id.update);
                readAll();
                delete();
                updateData();
    }


    public void updateData(){
             update.setOnClickListener(
                    new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            String username = username1.getText().toString();
                            String birth = DofB.getText().toString();
                            String pass = password.getText().toString();
                            int selectedID = radioGroup.getCheckedRadioButtonId();
                            genderRadioButton = (RadioButton)findViewById(selectedID);
                            String gender = genderRadioButton.getText().toString();

                            UserProfile.Users users = UserProfile.getProfile().getUser();
                            users.setUserName(username);
                            users.setDateOfBirth(birth);
                            users.setPassword(pass);
                            users.setGender(gender);

                            boolean isUpdate = myDb.updateData(users);

                            if(isUpdate == true){
                                Toast.makeText(EditProfile.this,"Data Update", Toast.LENGTH_SHORT).show();
                            }
                            else{
                                Toast.makeText(EditProfile.this,"Data not update",Toast.LENGTH_SHORT).show();
                            }
                        }
                    }
                );

    }


    public void readAll(){

                viewDetails.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {

                        Cursor res = myDb.readAllInfor();

                        if(res.getCount() == 0){

                            Toast.makeText(EditProfile.this,"Error",Toast.LENGTH_SHORT).show();
                        }
                        else{
                            StringBuffer buffer = new StringBuffer();

                            while(res.moveToNext()){
                                buffer.append("ID :" + res.getString(0) + "\n");
                                buffer.append("Username :" + res.getString(1) + "\n");
                                buffer.append("Date of Birth :" + res.getString(2) + "\n");
                                buffer.append("Password :" + res.getString(3) + "\n");
                                buffer.append("Gender :" + res.getString(4) + "\n");


                            }
                            showMessage("Details", buffer.toString());

                        }

                }
                });
    }

   public void delete(){
                dele.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        String uname = username1.getText().toString();
                        UserProfile.Users users = UserProfile.getProfile().getUser();
                        users.setUserName(uname);
                        Integer deleteRows = myDb.deleteData(users);

                        if(deleteRows > 0){
                            Toast.makeText(EditProfile.this,"Data Deleted Succesfully ", Toast.LENGTH_SHORT).show();
                        }
                        else{
                            Toast.makeText(EditProfile.this,"Data not Deleted Succesfully",Toast.LENGTH_SHORT).show();
                        }
                    }
                });


    }


    public void showMessage(String title,String message){

                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setCancelable(true);
                builder.setTitle(title);
                builder.setMessage(message);
                builder.show();

    }

}

这是我用来制作一个简单android程序的全部代码。我是android studio的初学者，我想知道如何更正Home.java类中的注释代码，以允许仅访问系统的注册成员。

Answer 1

尝试类似这样的方法：从列表中的db获取所有用户，或以相同的方式遍历db。

public void login(View v){
    boolean exists = false;
    EditText name = findViewById(R.id.username);
    String nameinput = name.getText().toString();
    EditText pass = findViewById(R.id.password);
    String passinput = pass.getText().toString();
    if (nameinput.isEmpty() || passinput.isEmpty()){
        Toast.makeText(this, "Please enter Your username and password.", Toast.LENGTH_LONG);
        setContentView(R.layout.activity_main);
    } else {
        for (User u : usersList) {
            if (nameinput.equals(u.getUsername()) && passinput.equals(u.getPassword())){
                exists = true;
                Intent i = new Intent(this, MainMenuActivity.class);
                startActivity(i);
                break;
            }
        }
        if (!exists){
            Intent i = new Intent(this, RegisterActivity.class);
            startActivity(i);
        }
    }
}

用户登录和简单的应用程序数据-如何制作？

1 个答案: