安卓:注册用户时，Asyctask在JSON解析过程中不起作用

Question

可能重复：
android-原因：android.view.ViewRootImpl$CalledFromWrongThreadException

我正在使用此示例http://www.androidhive.info/2012/01/android-login-and-registration-with-php-mysql-and-sqlite/当我在注册表中注册了我的详细信息时，它将数据保存在数据库中，但应用程序崩溃，它给出了以下错误

Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

我的注册码低于

Register.java

import org.json.JSONException;
import org.json.JSONObject;

import com.example.petencare.library.JSONParser;
import com.example.petencare.library.DatabaseHandler;
import com.example.petencare.library.UserFunctions;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.util.Log;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

/**
 * Handles the user registration activity.
 * 
 */
public class Register extends Activity {
    JSONParser jsonParser = new JSONParser();
    private EditText newUsername;
    private EditText newPassword;
    private EditText newConfiPass;
    private EditText newName;
    private EditText newPhone;
    private TextView Alreadyuser;
    private Button registerButton;
    private TextView registerErrorMsg;
    private ProgressDialog pDialog;
    // JSON Response node names
    private static String KEY_SUCCESS = "success";
    private static String KEY_ERROR = "error";
    private static String KEY_ERROR_MSG = "error_msg";
    private static String KEY_UID = "uid";
    private static String KEY_EMAIL = "email";
    private static String KEY_NAME = "name";
    private static String KEY_MOBILE = "mobile";
    private static String KEY_CREATED_AT = "created_at";

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

            newUsername = (EditText) findViewById(R.id.reg_email);
            newPassword = (EditText) findViewById(R.id.reg_pass);
            newConfiPass = (EditText) findViewById(R.id.reg_passre);
            newName      =(EditText)findViewById(R.id.reg_name);
            newPhone      =(EditText)findViewById(R.id.reg_mobile);
            registerButton = (Button) findViewById(R.id.btnRegister);
            Alreadyuser =    (TextView)findViewById(R.id.link_to_login);
            registerErrorMsg= (TextView)findViewById(R.id.register_error);
            Alreadyuser.setOnClickListener(new TextView.OnClickListener(){ 
                public void onClick (View v){ 
                    Intent i = new Intent(v.getContext(), Login.class);
                    startActivity(i);
                    // Close Registration View
                    finish();
                }
            });

            registerButton.setOnClickListener(new View.OnClickListener() { 
                public void onClick (View view){ 
                new Registeruser().execute();
                }
            });
     }
            class Registeruser extends AsyncTask<String, String, String> {

                @Override
                protected void onPreExecute() {
                    super.onPreExecute();
                    pDialog = new ProgressDialog(Register.this);
                    pDialog.setMessage("Registering. Please wait...");
                    pDialog.setIndeterminate(false);
                    pDialog.setCancelable(false);
                    pDialog.show();
                }

            protected  String doInBackground(String... args) {
                    //Get user details. 
            String email = newUsername.getText().toString();
            String password = newPassword.getText().toString();
            String confirmpassword = newConfiPass.getText().toString();
            String name=           newName.getText().toString();
            String mobile =   newPhone.getText().toString();

            //Check if all fields have been completed.
            if (email.equals("") || password.equals("") || name.equals("") || mobile.equals("")){
                Toast.makeText(getApplicationContext(), 
                        "Please ensure all fields have been completed.",
                          Toast.LENGTH_SHORT).show();
            return null;
            }
            //Check password match. 
            if (!password.equals(confirmpassword)) {
                Toast.makeText(getApplicationContext(), 
                        "The password does not match.",
                            Toast.LENGTH_SHORT).show();
                            newPassword.setText("");
                            newConfiPass.setText("");
                return null;
            }
             UserFunctions userFunction = new UserFunctions();
             JSONObject json = userFunction.registerUser(email, password, name, mobile);

             // check for login response
             try {
                 if (json.getString(KEY_SUCCESS) != null) {
                     registerErrorMsg.setText("");
                     String res = json.getString(KEY_SUCCESS);
                     if(Integer.parseInt(res) == 1){
                         // user successfully registred
                         // Store user details in SQLite Database
                         DatabaseHandler db = new DatabaseHandler(getApplicationContext());
                         JSONObject json_user = json.getJSONObject("user");
                         // Clear all previous data in database
                         userFunction.logoutUser(getApplicationContext());
                         db.addUser(json_user.getString(KEY_EMAIL), json_user.getString(KEY_NAME), json.getString(KEY_UID), json_user.getString(KEY_MOBILE), json_user.getString(KEY_CREATED_AT));
                         // Launch Dashboard Screen
                         Intent dashboard1 = new Intent(getApplicationContext(), MainActivity.class);
                         // Close all views before launching Dashboard
                         dashboard1.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                         startActivity(dashboard1);
                         // Close Registration Screen
                         finish();
                     }else{
                         // Error in registration
                         registerErrorMsg.setText("User already existed");
                     }
                 }
             } catch (JSONException e) {
                 e.printStackTrace();
             }  
             return null;
            }
            @Override
    protected void onPostExecute(String file_url){
        // dismiss the dialog once done
        pDialog.dismiss();
            }

     }
}

我使用JSON解析来发送数据，我有一个userfunction.java类，代码在下面

import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONObject;
import android.content.Context;
public class UserFunctions {
    private JSONParser jsonParser;
    // Testing in localhost using wamp or xampp
    // use http://10.0.2.2/ to connect to your localhost ie http://localhost/
    private static String loginURL = "http://www.mywebsite.com/android_login_api/";
    private static String registerURL = "http://www.mywebsite.com/android_login_api/";
    private static String login_tag = "login";
    private static String register_tag = "register";
    // constructor
    public UserFunctions(){
        jsonParser = new JSONParser();
    }
    /**
     * function make Login Request
     * @param email
     * @param password
     * */
    public JSONObject loginUser(String email, String password){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", login_tag));
        params.add(new BasicNameValuePair("email", email));
        params.add(new BasicNameValuePair("password", password));
        JSONObject json = jsonParser.getJSONFromUrl(loginURL, params);
        // return json
        // Log.e("JSON", json.toString());
        return json;
    }
    /**
     * function make Login Request
     * @param name
     * @param email
     * @param password
     * */
    public JSONObject registerUser(String email, String password, String name, String mobile){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", register_tag));
        params.add(new BasicNameValuePair("email", email));
        params.add(new BasicNameValuePair("password", password));
        params.add(new BasicNameValuePair("name", name));
        params.add(new BasicNameValuePair("mobile", mobile));
        // getting JSON Object
        JSONObject json = jsonParser.getJSONFromUrl(registerURL, params);
        // return json
        return json;
    }
    /**
     * Function get Login status
     * */
    public boolean isUserLoggedIn(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        int count = db.getRowCount();
        if(count > 0){
            // user logged in
            return true;
        }
        return false;
    }
    /**
     * Function to logout user
     * Reset Database
     * */
    public boolean logoutUser(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        db.resetTables();
        return true;
    }
}

请帮我提前感谢

Answer 1

我收到错误

引起原因：android.view.ViewRootImpl$CalledFromWrongThreadException：只有创建视图层次结构的原始线程才能接触其视图。

意味着您正试图从AsyncTask的doInBackground访问UI元素。不可能从非Ui线程访问Ui元素或生成CCD_ 2。

解决方案是在启动AsyncTask之前移动所有类似EditText验证的代码，并使用AsyncTask的onPreExecute在doInBackground中获取EditText值，在doInBackground执行完成时使用onPostExecute更新Ui

编辑：

根据OP请求，将所有验证移动到内部按钮点击为：

    registerButton.setOnClickListener(new View.OnClickListener() { 
        public void onClick (View view){ 
        //  PUT YOUR ALL VALIDATION HERE
        
        if(/* if validation success  */){
           
            // start AsyncTask here
            new Registeruser().execute();
         }
         else{
                // show validation error here
          }
        }
    });

Answer 2

尝试在doInBackground((方法中删除Toasts。当您访问doInBackground()中的UI以显示祝酒词时，甚至为什么不能在启动异步任务之前移动验证部分。

Answer 3

我认为应该使用RunOnuithread方法，或者在Asynctask方法的doInBackground()中使用Handler While。

这种方式使用

    @Override
    protected Long doInBackground(String... urls) {
        // Already suggested by Dixit Patel:
        // Use the runOnUiThread method.
        // See his explanation.
        runOnUiThread(new Runnable() {
     @Override
         public void run() {
         if (!password.equals(confirmpassword)) {
            Toast.makeText(getApplicationContext(), 
                    "The password does not match.",
                        Toast.LENGTH_SHORT).show();
                        newPassword.setText("");
                        newConfiPass.setText("");
        }
     }
    });