Question

所以我创建了一个简单的登录活动。当用户未能登录3次时，登录按钮将被禁用一段时间。

我的困难是当我关闭应用程序并再次打开它时按钮被启用。如何解决这个问题？

这是我的代码：

public class LoginControl extends Activity {
private DBControl db = new DBControl(this);
int counter = 2;
Button login = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.loginview);


    Button register = (Button) findViewById(R.id.btnCreateA);
    login = (Button) findViewById(R.id.btnLogin);
    login.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
                EditText a = (EditText) findViewById(R.id.etUser);
                EditText b = (EditText) findViewById(R.id.etPassword);
                String user = a.getText().toString();
                String pass = b.getText().toString();
                String confirm = db.getUserPass(user);
                if (user.equals("") || pass.equals("")) {
                    Toast passed = Toast.makeText(LoginControl.this, "Please input required fields.", Toast.LENGTH_LONG);
                    passed.show();
                } else if (pass.equals(confirm)) {
                    Toast passed = Toast.makeText(LoginControl.this, "Sucess!", Toast.LENGTH_LONG);
                    passed.show();
                    Intent intent = new Intent(LoginControl.this, HomeControl.class).putExtra("Music", false);
                    startActivity(intent);
                    finish();

                } else if (counter == 0)
                // Disable button after 3 failed attempts
                {

                    login.setEnabled(false);

                    Toast alert = Toast.makeText(LoginControl.this, "Login Disabled for 5 mins", Toast.LENGTH_LONG);
                    alert.show();

                    final Handler handler = new Handler();
                    handler.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            login.setEnabled(true);
                            counter = 2;
                        }
                    }, 30000);
                } else {
                    Toast passed = Toast.makeText(LoginControl.this, "Username or password don't match!", Toast.LENGTH_LONG);
                    counter--;
                    passed.show();
                }
            } catch (Exception e) {
                Toast passed = Toast.makeText(LoginControl.this, e.toString(), Toast.LENGTH_LONG);
                passed.show();
            }
        }
    });
}

}

Answer 1

要获取此信息，即使重新启动应用程序，您也需要节省再次启用该按钮的时间。当您的应用启动时，您可以打开此信息并检查它是在此时间之前还是之后。

有几种方法，如何在android上存储信息：

共享偏好设置：https://developer.android.com/training/basics/data-storage/shared-preferences.html
SQLite数据库：https://developer.android.com/training/basics/data-storage/databases.html
另存为文件：https://developer.android.com/training/basics/data-storage/files.html

对于您的问题，我建议您使用共享首选项。

Answer 2

使用共享偏好设置，在login.setEnabled(false)之后保存按钮的状态：

SharedPreferences prefs = this.getSharedPreferences("MyApp", Context.MODE_PRIVATE);
boolean enabled = login.isEnabled();
prefs.edit().putBoolean("LOGIN_ENABLED_KEY", enabled).apply();

抓住login中的onCreate按钮后，检查是否存在此值（使用true作为默认值）：

SharedPreferences prefs = this.getSharedPreferences("MyApp", Context.MODE_PRIVATE);
boolean enabled = prefs.getBoolean("LOGIN_ENABLED_KEY", true);
login.setEnabled(enabled);

如果此时禁用该按钮，则需要重新启动计时器，以便最终启用它：

if (!enabled) {
    final Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            login.setEnabled(true);
            prefs.edit().clear().apply();
            counter = 2;
        }
    }, 30000);
}

计时器结束时：

SharedPreferences prefs = this.getSharedPreferences("MyApp", Context.MODE_PRIVATE);
prefs.edit().putBoolean("LOGIN_ENABLED_KEY", true).apply();

或者，只需清除共享首选项：

SharedPreferences prefs = this.getSharedPreferences("MyApp", Context.MODE_PRIVATE);
prefs.edit().clear().apply();

把它们放在一起，大致是这样的：

int counter = 2;
Button login = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.loginview);

    final SharedPreferences prefs = this.getSharedPreferences("MyApp", Context.MODE_PRIVATE);
    login = (Button) findViewById(R.id.btnLogin);
    boolean enabled = prefs.getBoolean("LOGIN_ENABLED_KEY", true);
    login.setEnabled(enabled);
    if (!enabled) {
        final Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                login.setEnabled(true);
                prefs.edit().clear().apply();
                counter = 2;
            }
        }, 30000);
    }

    login.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             try {
                 EditText a = (EditText) findViewById(R.id.etUser);
                 EditText b = (EditText) findViewById(R.id.etPassword);
                 String user = a.getText().toString();
                 String pass = b.getText().toString();
                 if (user.equals("") || pass.equals("")) {
                     Toast passed = Toast.makeText(LoginControl.this, "Please input required fields.", Toast.LENGTH_LONG);
                     passed.show();
                 } else if (pass.equals("pass")) {
                     Toast passed = Toast.makeText(LoginControl.this, "Success!", Toast.LENGTH_LONG);
                     passed.show();
                     // Start HomeControl + finish()
                 } else if (counter == 0) {
                     // Disable button after 3 failed attempts
                     login.setEnabled(false);
                     prefs.edit().putBoolean("LOGIN_ENABLED_KEY", false).apply();
                     Toast alert = Toast.makeText(LoginControl.this, "Login Disabled for 5 mins", Toast.LENGTH_LONG);
                     alert.show();

                     final Handler handler = new Handler();
                     handler.postDelayed(new Runnable() {
                         @Override
                         public void run() {
                             login.setEnabled(true);
                             prefs.edit().clear().apply();
                             counter = 2;
                         }
                     }, 30000);
                 } else {
                     Toast passed = Toast.makeText(LoginControl.this, "Username or password don't match!", Toast.LENGTH_LONG);
                     counter--;
                     passed.show();
                 }
             } catch (Exception e) {
                 Toast passed = Toast.makeText(LoginControl.this, e.toString(), Toast.LENGTH_LONG);
                 passed.show();
             }
         }
    });
}

（这里有一些重构的空间，但确实有效。）

即使应用程序关闭，如何暂时禁用按钮？

2 个答案: