当我运行应用程序并登录时，用户数据未显示在仪表板上，并且在修改代码后出现此错误
错误：无法将SessionSession类中的方法loginUser应用于给定类型； 必需：String，String，String 找到：字符串，字符串 原因：实际和正式论据列表的长度不同
我如何解决此错误？
登录法类
<div class="container">
<div id="carouselContent" class="carousel slide" data-ride="carousel">
<ol class="carousel-indicators">
<li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
<li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
<li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
</ol>
<div class="carousel-inner">
<div class="carousel-item active text-center">
<p>Testimonial 1</p>
</div>
<div class="carousel-item text-center">
<p>Testimonial 2</p>
</div>
<div class="carousel-item text-center">
<p>Testimonial 3</p>
</div>
</div>
<a class="carousel-control-prev" href="#carouselContent" role="button" data-slide="prev">
<span class="carousel-control-prev-icon" aria-hidden="true"></span>
<span class="sr-only">Previous</span>
</a>
<a class="carousel-control-next" href="#carouselContent" role="button" data-slide="next">
<span class="carousel-control-next-icon" aria-hidden="true"></span>
<span class="sr-only">Next</span>
</a>
</div>
</div>
</section>
#carouselContent{
height: 200px;
}
.container {
background-color: blue;
color: white;
}
Expecting testimonial to align vertically in the center but now align at the top of the div.
sessionhandler类
package com.androidigniter.loginandregistration;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import org.json.JSONException;
import org.json.JSONObject;
public class LoginActivity extends AppCompatActivity {
private static final String KEY_STATUS = "status";
private static final String KEY_MESSAGE = "message";
private static final String KEY_FULL_NAME = "full_name";
private static final String KEY_USERNAME = "username";
private static final String KEY_PASSWORD = "password";
private static final String KEY_EMPTY = "";
private EditText etUsername;
private EditText etPassword;
private String username;
private String password;
private ProgressDialog pDialog;
private String login_url = "http://192.168.1.102/member/login.php";
private SessionHandler session;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
session = new SessionHandler(getApplicationContext());
if(session.isLoggedIn()){
loadDashboard();
}
setContentView(R.layout.activity_login);
etUsername = findViewById(R.id.etLoginUsername);
etPassword = findViewById(R.id.etLoginPassword);
Button register = findViewById(R.id.btnLoginRegister);
Button login = findViewById(R.id.btnLogin);
//Launch Registration screen when Register Button is clicked
register.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(LoginActivity.this, RegisterActivity.class);
startActivity(i);
finish();
}
});
login.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Retrieve the data entered in the edit texts
username = etUsername.getText().toString().toLowerCase().trim();
password = etPassword.getText().toString().trim();
if (validateInputs()) {
login();
}
}
});
}
/**
* Launch Dashboard Activity on Successful Login
*/
private void loadDashboard() {
Intent i = new Intent(getApplicationContext(), DashboardActivity.class);
startActivity(i);
finish();
}
/**
* Display Progress bar while Logging in
*/
private void displayLoader() {
pDialog = new ProgressDialog(LoginActivity.this);
pDialog.setMessage("Logging In.. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
private void login() {
displayLoader();
JSONObject request = new JSONObject();
try {
//Populate the request parameters
request.put(KEY_USERNAME, username);
request.put(KEY_PASSWORD, password);
} catch (JSONException e) {
e.printStackTrace();
}
JsonObjectRequest jsArrayRequest = new JsonObjectRequest
(Request.Method.POST, login_url, request, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
pDialog.dismiss();
try {
//Check if user got logged in successfully
if (response.getInt(KEY_STATUS) == 0) {
session.loginUser(username,response.getString(KEY_FULL_NAME));
loadDashboard();
}else{
Toast.makeText(getApplicationContext(),
response.getString(KEY_MESSAGE), Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
pDialog.dismiss();
//Display error message whenever an error occurs
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_SHORT).show();
}
});
// Access the RequestQueue through your singleton class.
MySingleton.getInstance(this).addToRequestQueue(jsArrayRequest);
}
/**
* Validates inputs and shows error if any
* @return
*/
private boolean validateInputs() {
if(KEY_EMPTY.equals(username)){
etUsername.setError("Username cannot be empty");
etUsername.requestFocus();
return false;
}
if(KEY_EMPTY.equals(password)){
etPassword.setError("Password cannot be empty");
etPassword.requestFocus();
return false;
}
return true;
}
}
用户类别
package com.androidigniter.loginandregistration;
import android.content.Context;
import android.content.SharedPreferences;
import java.util.Date;
/**
* Created by AndroidIgniter on 23 Mar 2019 020.
*/
public class SessionHandler {
private static final String PREF_NAME = "UserSession";
private static final String KEY_USERNAME = "username";
private static final String KEY_EXPIRES = "expires";
private static final String KEY_FULL_NAME = "full_name";
private static final String KEY_CARD_ID = "cardid";
private static final String KEY_EMPTY = "";
private Context mContext;
private SharedPreferences.Editor mEditor;
private SharedPreferences mPreferences;
public SessionHandler(Context mContext) {
this.mContext = mContext;
mPreferences = mContext.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
this.mEditor = mPreferences.edit();
}
/**
* Logs in the user by saving user details and setting session
*
* @param username
* @param fullName
* @param cardid
*/
public void loginUser(String username, String fullName , String cardid) {
mEditor.putString(KEY_USERNAME, username);
mEditor.putString(KEY_FULL_NAME, fullName);
mEditor.putString(KEY_CARD_ID, cardid);
Date date = new Date();
//Set user session for next 7 days
long millis = date.getTime() + (7 * 24 * 60 * 60 * 1000);
mEditor.putLong(KEY_EXPIRES, millis);
mEditor.commit();
}
/**
* Checks whether user is logged in
*
* @return
*/
public boolean isLoggedIn() {
Date currentDate = new Date();
long millis = mPreferences.getLong(KEY_EXPIRES, 0);
/* If shared preferences does not have a value
then user is not logged in
*/
if (millis == 0) {
return false;
}
Date expiryDate = new Date(millis);
/* Check if session is expired by comparing
current date and Session expiry date
*/
return currentDate.before(expiryDate);
}
/**
* Fetches and returns user details
*
* @return user details
*/
public User getUserDetails() {
//Check if user is logged in first
if (!isLoggedIn()) {
return null;
}
User user = new User();
user.setUsername(mPreferences.getString(KEY_USERNAME, KEY_EMPTY));
user.setFullName(mPreferences.getString(KEY_FULL_NAME, KEY_EMPTY));
user.setCardId(mPreferences.getString(KEY_CARD_ID, KEY_EMPTY));
user.setSessionExpiryDate(new Date(mPreferences.getLong(KEY_EXPIRES, 0)));
return user;
}
/**
* Logs out user by clearing the session
*/
public void logoutUser(){
mEditor.clear();
mEditor.commit();
}
}
答案 0 :(得分：2)
您对loginUser的定义是：
public void loginUser(String username, String fullName , String cardid)
而当您致电loginUser时：
session.loginUser(username,response.getString(KEY_FULL_NAME));
您使用2个String参数对其进行了调用。您需要提供另一个参数cardid或将函数定义更改为仅需要2个参数，例如：
public void loginUser(String username, String fullName)