package com.example.test1; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; import androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button registerButton, loginButton; private EditText usernameText, paswdEdit; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.user_login); init(); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.register: Intent intent = new Intent(MainActivity.this, RegisterActivity.class); startActivity(intent); break; case R.id.login: //注册时,我们引入了数据库,登录这里可以通过数据库进行验证,验证跳转到首页,不通过进行提示 if (validateLogin()) { Intent intent1 = new Intent(MainActivity.this, IndexActivity.class); Bundle bundle = new Bundle(); Database orangeDatabase = new Database(MainActivity.this); bundle.putString("username", usernameText.getText().toString()); bundle = orangeDatabase.queryUserInfo(orangeDatabase.getReadableDatabase(), bundle); intent1.putExtras(bundle); startActivity(intent1); } else { Toast.makeText(MainActivity.this, "账号或者密码错误", Toast.LENGTH_SHORT).show(); } break; } } //界面组件初始化 private void init() { usernameText = findViewById(R.id.username); paswdEdit = findViewById(R.id.password); loginButton = findViewById(R.id.login); loginButton.setOnClickListener(this); registerButton = findViewById(R.id.register); registerButton.setOnClickListener(this); } /** * 登录验证 * * @return */ private boolean validateLogin() { String username = usernameText.getText().toString(); String password = paswdEdit.getText().toString(); Database Database = new Database(MainActivity.this); SQLiteDatabase sqLiteDatabase = Database.getReadableDatabase(); Cursor cursor = sqLiteDatabase.rawQuery("select * from orange_user where username=? and password=?", new String[]{username, password}); if (cursor.getCount() > 0) { return true; } return false; } }