我遵循了一个教程，现在我得到了一个登录代码，可以检查用户是否存在并检查用户角色（管理员或用户）。
我读到要进入新页面，我们需要使用 Intent，但我如何让它的用户角色传递到 android 中？ 管理员将被定向到页面 A，用户将被定向到页面 B。
高级 Tqvm。
1.背景工作者.java
public class BackgroundWorker extends AsyncTask<String,Void,String> {
Context context;
AlertDialog alertDialog;
BackgroundWorker (Context ctx) {
context = ctx;
}
@Override
protected String doInBackground(String... params) {
String type = params[0];
String login_url = "http://ipaddress/foldername/login.php";
if(type.equals("login")) {
try {
String user_name = params[1];
String password = params[2];
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String post_data = URLEncoder.encode("user_name","UTF-8")+"="+URLEncoder.encode(user_name,"UTF-8")+"&"
+URLEncoder.encode("password","UTF-8")+"="+URLEncoder.encode(password,"UTF-8");
bufferedWriter.write(post_data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
String result="";
String line="";
while((line = bufferedReader.readLine())!= null) {
result += line;
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return result;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
@Override
protected void onPreExecute() {
alertDialog = new AlertDialog.Builder(context).create();
alertDialog.setTitle("Login Status");
}
@Override
protected void onPostExecute(String result) {
alertDialog.setMessage(result);
alertDialog.show();
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
}
2.主要活动.java
public class MainActivity extends AppCompatActivity {
EditText UsernameEt, PasswordEt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
UsernameEt = (EditText) findViewById(R.id.etUserName);
PasswordEt = (EditText) findViewById(R.id.etPassword);
}
public void OnLogin(View view){
String username = UsernameEt.getText().toString();
String password = PasswordEt.getText().toString();
String type = "login";
BackgroundWorker backgroundWorker = new BackgroundWorker(this);
backgroundWorker.execute(type, username, password);
}
}
3.登录.php
<?php
require "conn.php";
$user_name = $_POST["user_name"];
$user_pass = $_POST["password"];
$mysql_qry = "select * from employee_data where username like '$user_name' and password like '$user_pass';";
$result = mysqli_query($conn, $mysql_qry);
if(mysqli_num_rows($result) > 0){
while ($data =mysqli_fetch_array($result))
{
$userrole = $data['role'];
if ($userrole == "admin"){
echo "login admin successful";
}
else if ($userrole == "user")
{
echo "login user successful";
}
}
}
else{
echo "login unsuccessful";
}
?>
P.S 我对安卓非常陌生，所以非常感谢任何解释。
如果登录成功，您可以在 PHP 脚本中回显角色：
echo $user['role'];
并且只回显"登录失败"或只是"失败"。然后，您可以像这样解析来自onPostExecute()方法的响应：
switch (result) {
case "failed":
// Login failed.
break;
case "user": // Login successful, result (role) is "user"
break;
case "admin": // Login successful, result (role) is "admin"
break;
}
如果要将此角色传递回活动，可以在AsyncTask上实现一个侦听器接口，该接口将在调用 onPostExecute() 方法时调用。例如：
public class BackgroundWorker extends AsyncTask<String,Void,String> {
... // Member properties.
// Define the listener interface.
public interface OnTaskFinishedListener {
void onTaskFinished(String result);
}
// Member property to reference listener.
private OnTaskFinishedListener mOnTaskFinishedListener;
// Setter for listener.
public void setOnTaskFinishedListener(OnTaskFinishedListener listener) {
mOnTaskFinishedListener = listener;
}
// Invoke the listener in the onPostExecute() method.
@Override
protected void onPostExecute(String result) {
// Only call it if it's set.
if (mOnTaskFinishedListener != null)
mOnTaskFinishedListener.onTaskFinished(result);
}
}
然后在您的活动中，在OnLogin()：
public void OnLogin(View view) {
String username = UsernameEt.getText().toString();
String password = PasswordEt.getText().toString();
String type = "login";
BackgroundWorker backgroundWorker = new BackgroundWorker(this);
// Set your listener here.
backgroundWorker.setOnTaskFinishedListener(new BackgroundWorker.OnTaskFinishedListener() {
@Override
public void onTaskFinished(String result) {
// Now you have the result of your login here.
// Result should be "admin", "user", or "failed"
// You can now create an intent and open the page
// to your next activity.
switch (result) {
case "admin":
// Create your intent.
Intent adminIntent = new Intent(MainActivity.this, AdminPageActivity.class);
// Start the admin page activity.
startActivity(adminIntent);
break;
case "user":
// Create your intent.
Intent userIntent = new Intent(MainActivity.this, UserPageActivity.class);
// Start the user page activity.
startActivity(userIntent);
break;
default:
// Login failed.
}
}
});
backgroundWorker.execute(type, username, password);
}
听众的东西一开始可能很难掌握，但一旦你这样做了，它就会非常强大。 希望这有帮助！