如何在片段活动中获取用户名？
Posted
技术标签:
【中文标题】如何在片段活动中获取用户名？【英文标题】：How to take username in fragment activity? 【发布时间】：2020-06-08 10:49:43 【问题描述】：我是 android 新手，我使用 mysql 设计了一个登录表单，现在我想在配置文件片段中显示用户登录名，因为我为登录会话设置了 Sharedprefernces。
这是我的登录类
public class LoginActivity extends AppCompatActivity
private static final String TAG = RegisterActivity.class.getSimpleName();
private Button btnLogin;
private Button btnLinkToRegister;
private EditText inputEmail;
private EditText inputPassword;
private ProgressDialog pDialog;
private SessionManager session;
private SQLiteHandler db;
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
inputEmail = findViewById(R.id.email);
inputPassword = findViewById(R.id.password);
btnLogin = findViewById(R.id.btnLogin);
btnLinkToRegister = findViewById(R.id.btnLinkToRegisterScreen);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// SQLite database handler
db = new SQLiteHandler(getApplicationContext());
// Session manager
session = new SessionManager(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn())
// User is already logged in. Take him to main activity
Intent intent = new Intent(LoginActivity.this, MainActivity.class);
startActivity(intent);
finish();
// Login button Click Event
btnLogin.setOnClickListener(new View.OnClickListener()
public void onClick(View view)
String email = inputEmail.getText().toString().trim();
String password = inputPassword.getText().toString().trim();
// Check for empty data in the form
if (!email.isEmpty() && !password.isEmpty())
// login user
checkLogin(email, password);
else
// Prompt user to enter credentials
Toast.makeText(getApplicationContext(),
"Please enter the credentials!", Toast.LENGTH_LONG)
.show();
);
// Link to Register Screen
btnLinkToRegister.setOnClickListener(new View.OnClickListener()
public void onClick(View view)
Intent i = new Intent(getApplicationContext(),
RegisterActivity.class);
startActivity(i);
finish();
);
/**
* function to verify login details in mysql db
*/
private void checkLogin(final String email, final String password)
// Tag used to cancel the request
String tag_string_req = "req_login";
pDialog.setMessage("Logging in ...");
showDialog();
StringRequest strReq = new StringRequest(Request.Method.POST,
AppConfig.URL_LOGIN, new Response.Listener<String>()
@Override
public void onResponse(String response)
Log.d(TAG, "Login Response: " + response);
hideDialog();
try
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");
// Check for error node in json
if (!error)
// user successfully logged in
// Create login session
session.setLogin(true);
// Now store the user in SQLite
String uid = jObj.getString("uid");
JSONObject user = jObj.getJSONObject("user");
String name = user.getString("name");
String email = user.getString("email");
String created_at = user.getString("created_at");
// Inserting row in users table
db.addUser(name, email, uid, created_at);
// Launch main activity
Intent intent = new Intent(LoginActivity.this,
MainActivity.class);
startActivity(intent);
finish();
else
// Error in login. Get the error message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
catch (JSONException e)
// JSON error
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
, new Response.ErrorListener()
@Override
public void onErrorResponse(VolleyError error)
Log.e(TAG, "Login Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
)
@Override
protected Map<String, String> getParams()
// Posting parameters to login url
Map<String, String> params = new HashMap<>();
params.put("email", email);
params.put("password", password);
return params;
;
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
private void showDialog()
if (!pDialog.isShowing())
pDialog.show();
private void hideDialog()
if (pDialog.isShowing())
pDialog.dismiss();
这里也是 SessionManager 类
public class SessionManager
// LogCat tag
private static String TAG = SessionManager.class.getSimpleName();
// Shared Preferences
private SharedPreferences pref;
private SharedPreferences.Editor editor;
// Shared preferences file name
private static final String PREF_NAME = "AndroidHiveLogin";
private static final String KEY_IS_LOGGEDIN = "isLoggedIn";
public SessionManager(Context context)
// Shared pref mode
int PRIVATE_MODE = 0;
pref = context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
public void setLogin(boolean isLoggedIn)
editor.putBoolean(KEY_IS_LOGGEDIN, isLoggedIn);
// commit changes
editor.commit();
Log.d(TAG, "User login session modified!");
public boolean isLoggedIn()
return pref.getBoolean(KEY_IS_LOGGEDIN, false);
这是个人资料片段
public class ProfileFragment extends Fragment
private TextView txtName;
private SessionManager session;
public ProfileFragment()
// Required empty public constructor
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_profile, container, false);
如何在个人资料片段中显示用户登录名请帮助我提前致谢。
【问题讨论】：
【参考方案1】：实际上有很多方法可以做到这一点。在您的情况下，我认为这样做的便捷方法是将登录名存储在SharedPreferences 中，然后从SharedPreferences 中的ProfileFragment 中获取值。
因此，当您执行session.setLogin(true); 时，您可以将另一个具有登录名的键值对保存到SharedPreferences 中，然后您可以稍后从片段中检索来自SharedPreferences 的值。
因此，在ProfileFragment 的onCreateView 函数中，您可能会执行以下操作。
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
SessionManager sessionManager = new SessionManager(getActivity());
// Considering you have the function to store and retrieve the login name from the SharedPreferences in your SessionManager class.
String loginName = sessionManager.getLoginName(); // get the login name here
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_profile, container, false);
如我所见，您将用户配置文件信息存储在数据库中。因此，您也可以在片段中显示数据库中的用户配置文件信息。我有一个github project，您可以在其中查看如何在 SQLite 数据库中存储/读取。
希望对你有帮助。
更新
您的SessionManager 类中可能有以下函数。
public class SessionManager
// LogCat tag
private static String TAG = SessionManager.class.getSimpleName();
// Shared Preferences
private SharedPreferences pref;
private SharedPreferences.Editor editor;
// Shared preferences file name
private static final String PREF_NAME = "AndroidHiveLogin";
private static final String KEY_IS_LOGGEDIN = "isLoggedIn";
private static final String KEY_LOGIN_NAME = "loginName";
public SessionManager(Context context)
// Shared pref mode
int PRIVATE_MODE = 0;
pref = context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
public void setLogin(boolean isLoggedIn)
editor.putBoolean(KEY_IS_LOGGEDIN, isLoggedIn);
// commit changes
editor.commit();
Log.d(TAG, "User login session modified!");
public boolean isLoggedIn()
return pref.getBoolean(KEY_IS_LOGGEDIN, false);
// These are the new functions that I added in your SessionManager class
public void setLoginName(String loginName)
editor.putString(KEY_LOGIN_NAME, loginName).apply();
public boolean getLoginName()
return pref.getString(KEY_LOGIN_NAME, null);
在LoginActivity 的 API 请求部分，您可能会考虑执行以下操作。
if (!error)
// user successfully logged in
// Create login session
session.setLogin(true);
// Now store the user in SQLite
String uid = jObj.getString("uid");
JSONObject user = jObj.getJSONObject("user");
String name = user.getString("name");
String email = user.getString("email");
String created_at = user.getString("created_at");
// Save login name in the SharedPreferences here
session.setLoginName(name);
// Inserting row in users table
db.addUser(name, email, uid, created_at);
// Launch main activity
Intent intent = new Intent(LoginActivity.this,
MainActivity.class);
startActivity(intent);
finish();
【讨论】：
怎么做我不明白请指导我 // 考虑到你有在你的 SessionManager 类的 SharedPreferences 中存储和检索登录名的功能。字符串登录名 = sessionManager.getLoginName(); // 在这里获取登录名 请检查答案的更新。我希望这能澄清困惑。 从未使用过真正的“登录名”。如何使用它？ 在您的片段中，使用该变量将文本设置为TextView 或布局中的其他内容？
我用它作为TextView textView=getView().findViewById(R.id.name); textView.setText(登录名);但应用程序崩溃了以上是关于如何在片段活动中获取用户名？的主要内容，如果未能解决你的问题，请参考以下文章