android 登录、注册相关功能实例
package login.com; import android.app.Activity; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; /** * 登录页面 * * @author 都市游侠 * */ public class Login extends Activity implements OnClickListener{ EditText use,password; Button login,register; Sql db; SQLiteDatabase sDatabase = null; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); use = (EditText)findViewById(R.id.userName); password = (EditText)findViewById(R.id.password); login = (Button)findViewById(R.id.login); register = (Button)findViewById(R.id.register); register.setOnClickListener(this); login.setOnClickListener(this); db = new Sql(getApplicationContext(), "store.db", null, 1); sDatabase = db.getWritableDatabase(); } @Override public void onClick(View v) { //获得用户名 String i = use.getText().toString(); // TODO Auto-generated method stub int id = v.getId(); //注册 if(id == R.id.register){ Intent intent = new Intent(); intent.setClass(Login.this, Register.class); startActivity(intent); } //登陆 if(id == R.id.login){ String userName = ""; String userPw = ""; //编写数据库语句 String select_sql = "select username,password from user_info where username = '" i "'"; //执行语句 Cursor cursor = sDatabase.rawQuery(select_sql, null); cursor.moveToFirst(); // 将从数据中取出的用户名和密码赋值给两个字符串变量 try { userName = cursor.getString(0); userPw = cursor.getString(1); } catch (Exception e) { // TODO: handle exception userName = ""; userPw = ""; } // 判断用户名是否为空 if (i.equals("")) { DialogDemo.builder(Login.this, "错误信息", "用户名不能为空!"); } // 判断密码是否为空 else if (password.getText().toString().equals("")) { DialogDemo.builder(Login.this, "错误信息", "密码不能为空!"); } // 判断用户名和密码是否正确 else if (!(use.getText().toString().equals(userName) && password .getText().toString().equals(userPw))) { DialogDemo.builder(Login.this, "错误信息", "用户名或密码错误,请重新输入"); } // 全部正确跳转到操作界面 else { cursor.close(); Intent intent = new Intent(); //Bundle bundle = new Bundle(); //bundle.putString("username",userName); //intent.putExtras(bundle); intent.setClass(Login.this, SuccessLogin.class); startActivity(intent); Toast.makeText(Login.this, "登陆成功", Toast.LENGTH_SHORT).show(); } } } }
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