java不能将片段和活动登录结合起来

Question

我刚从片段开始，想学习如何使用滑动菜单制作更多功能性应用程序，但我在setcontentview上出错，因为我想制作一个登录屏幕，这是一个活动。 链接到我的教程。 幻灯片菜单： 安卓 sliding menu 和登录屏幕： 安卓 login and register

public class LoginActivity extends Fragment {
public LoginActivity() {
    // Required empty public constructor
}
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;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_login);

    inputEmail = (EditText) getView().findViewById(R.id.email);
    inputPassword = (EditText) getView().findViewById(R.id.password);
    btnLogin = (Button) getView().findViewById(R.id.btnLogin);
    btnLinkToRegister = (Button) getView().findViewById(R.id.btnLinkToRegisterScreen);

    // Progress dialog
    pDialog = new ProgressDialog(this);
    pDialog.setCancelable(false);

    // 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, LoginMainActivity.class);
        startActivity(intent);
        finish();
    }

    // Login button Click Event
    btnLogin.setOnClickListener(new View.OnClickListener() {

        public void onClick(View view) {
            String email = inputEmail.getText().toString();
            String password = inputPassword.getText().toString();

            // Check for empty data in the form
            if (email.trim().length() > 0 && password.trim().length() > 0) {
                // 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(Method.POST,
            AppConfig.URL_REGISTER, new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            Log.d(TAG, "Login Response: " + response.toString());
            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);

                    // Launch main activity
                    Intent intent = new Intent(LoginActivity.this,
                            LoginMainActivity.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();
                } `

我在：-setContentView处得到错误

- pDialog = new ProgressDialog(this); 
- session = new SessionManager(getApplicationContext());
-           Intent intent = new Intent(LoginActivity.this, LoginMainActivity.class);
            startActivity(intent);
            finish();

Answer 1

您混合了Activity和Fragment。如果使用setContentView，则必须扩展Activity。 此外，您还会在此处遇到一个错误：

Intent intent = new Intent(LoginActivity.this,
                            LoginMainActivity.class);

因为LoginActivity是一个片段。 还有，这里

Intent i = new Intent(getApplicationContext(),
                        RegisterActivity.class);
                startActivity(i);

将LoginActivity的超类更改为Activity后，将getApplicationContext更改为LoginActivity.this