使用数据库中的数据填充微调器

时间：2015-01-17 15:46:02

标签： android mysql

我要做的是首先在数据库中插入一些值（参见insertvalues函数），然后从数据库中检索所有数据到spinner（参见getvalues函数）.i成功检索数据库中的数据，我检查过textboxes.but当我将这些数据设置到我的微调器适配器并运行应用程序时，我得到一个空的spinner.i明白我应该先写这行 My_spinner =（spinner）findViewbyid（ - ）然后调用getvalues函数，但当我尝试移动此行（My_spinner =（spinner）findViewbyid（ - ）在其他地方时，我的应用程序不再工作并且不幸地说应用程序已经关闭。我花了很多时间来弄清楚问题，但我不能，请帮助。

package com.example.gcmclientapp; 

import java.io.BufferedReader;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.StrictMode;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.DatabaseUtils;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemSelectedListener;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

public class GcmServer extends Activity {


     void showToast(CharSequence msg) {
            Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
        }



    // declarations for creating the database
    SQLiteDatabase mydb;
    String name_from_spinner;  // this will be used to filter the database for the required registrationID
    private   static String DBNAME = "new1.db";  // this is our database..change it when you use
    private static String TABLE = "MY_TABLE";
    //end of dec








    EditText et;
    String regId,userName;
    Button b;
    TextView tv,tv2;
    String temp="";
    String[] arr;
    Spinner My_spinner;
    InputStream is=null;

    ArrayList<String> my_array1 = new ArrayList<String>();
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gcmserver);
        b= (Button)findViewById(R.id.button1); 
        et=(EditText)findViewById(R.id.editText1);
        tv=(TextView)findViewById(R.id.textView1);
        tv2=(TextView)findViewById(R.id.textView2);


        regId = getIntent().getStringExtra("REGID");
        userName = getIntent().getStringExtra("USER");



          insertvalues();

          getTableValues();
          My_spinner = (Spinner) findViewById(R.id.spinner1);








        //setting on click listeners for the items of the spinner

        My_spinner.setOnItemSelectedListener(
                new OnItemSelectedListener() {
                    public void onItemSelected(
                        AdapterView<?> parent, View view, int position, long id) {
                        name_from_spinner=my_array1.get(position);
                        showToast(name_from_spinner);// get the name that has been clicked in the spinner





                    }

                    public void onNothingSelected(AdapterView<?> parent) {
                        showToast("Please enter contact");

                    }
                });







        // when the send button is clicked,we will extract the message from editText,regID and send to sendtoserver

        // send button
        b.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {

                String ID = null;
                String REGID=null;
                String NAME=null;
                String message =et.getText().toString(); //extract message from edit text
                // extract registration number
                 try {

                    mydb = openOrCreateDatabase(DBNAME, Context.MODE_PRIVATE, null);
                    Cursor allrows = mydb.rawQuery("SELECT * FROM " + TABLE, null);
                    if (allrows.moveToFirst()) {
                        do {

                             ID = allrows.getString(0);
                             REGID = allrows.getString(1);
                             NAME = allrows.getString(2);
                             if(NAME.equals(name_from_spinner)) // string comparison
                             {

                                 break;
                             }

                        } while (allrows.moveToNext());

                        showToast("left loop");


                    }



                    allrows.close();
                    mydb.close();
                } catch (Exception e) {
                    Toast.makeText(getApplicationContext(), "Error encountered.",
                            Toast.LENGTH_LONG);
                }
                 //tv.setText(REGID);
                 System.out.print(REGID);
                sendToServer(message,REGID);
            }

        }); 

    }



    //#########################################INSERT############################################################
    public void insertvalues()
    {
    StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
    List<NameValuePair> nameValuePairs=new ArrayList<NameValuePair>(1);
    nameValuePairs.add(new BasicNameValuePair("regid", regId));
    nameValuePairs.add(new BasicNameValuePair("name", userName));

    try {
          //tv2.setText(regId);
          HttpClient httpClient=new DefaultHttpClient();
          HttpPost httpPost=new HttpPost("http://192.168.1.3/new.php");
          httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
          HttpResponse response=httpClient.execute(httpPost);
          HttpEntity entity=response.getEntity();
          is=entity.getContent();
          showToast("data inserted successfully");






    }
    catch(ClientProtocolException e)
    {

         Log.e("clientProtocol","Log_tag");
         e.printStackTrace();

    }catch(IOException e)
    {
        Log.e("log_tag","ioexception");
        e.printStackTrace();

    }

    }


    public void sendToServer(final String message,final String ID){
        //tv2.setText(ID);
        new AsyncTask<String, Void, String>(){
        // changes are needed here
        @Override
        protected String doInBackground(String... params) {
            try {
                HttpResponse response = null;
                HttpParams httpParameters = new BasicHttpParams();
                HttpClient client = new DefaultHttpClient(httpParameters);
                String url="http://192.168.1.3/GCM/gcm.php?" + "&regID="+ ID + "&message="+ message; // changes needed here
                Log.i("Send URL:", url);
                HttpGet request = new HttpGet(url);

                response = client.execute(request);
                Log.i("responce URL:"," ");
                BufferedReader rd = new BufferedReader(new InputStreamReader(
                        response.getEntity().getContent()));

                String webServiceInfo = "";
                while ((webServiceInfo = rd.readLine()) != null) {
                    Log.d("****Status Log***", "Webservice: " + webServiceInfo);

                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
   }.execute(null,null,null);
  }
















 // ################################THIS FUNCTION SHOWS DATA FROM THE DATABASE#####################################
    public void getTableValues() {

        InputStream iss=null;
        String line=null;
        String result=null;
        StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);


        try {

              HttpClient httpClient=new DefaultHttpClient();
              HttpPost httpPost=new HttpPost("http://192.168.1.3/retrieve.php");

              HttpResponse response=httpClient.execute(httpPost);
              HttpEntity entity=response.getEntity();
              iss=entity.getContent();


              }
        catch(ClientProtocolException e)
        {

             System.out.println("exception 1  caught");

        }

        catch(IOException e)
        {
            Log.e("log_tag","ioexception");
            e.printStackTrace();

        }

        try{
            BufferedReader reader=new BufferedReader(new InputStreamReader(iss,"iso-8859-1"),8);
            StringBuilder sb=new StringBuilder();
            while((line=reader.readLine())!=null)

                        sb.append(line+"\n");
                        result=sb.toString();
                        //result now contains the data in the form of json
                        iss.close();
                        System.out.println("here is my data");
                        System.out.println(result);




        }
        catch(Exception e)
        {
            System.out.println("exception 2 caught");
        }

        try{

            JSONArray jArray=new JSONArray(result);
            int count=jArray.length();

            for(int i=0;i<count;i++)
            {
                JSONObject json_data=jArray.getJSONObject(i);
                temp+=json_data.getString("name")+":";



            }
            //System.out.println(temp);
            arr=temp.split(":");
            tv.setText(arr[1]);
            tv2.setText(arr[2]);



            ArrayAdapter my_Adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item,
                    arr);

            My_spinner.setAdapter(my_Adapter);


        }
        catch(Exception e)
        {
            System.out.println("m so boread");
            //System.out.println("hello");
        }



    }

  //###############################################################################################################  
 }

//按建议编辑代码后记录cat

01-17 21：27：32.939：D / dalvikvm（1895）：GC_FOR_ALLOC释放172K，3％免费9493K / 9692K，暂停3ms，总计3ms 01-17 21：27：33.019：W / EGL_genymotion（1895）：eglSurfaceAttrib未实现 01-17 21：27：33.075：D / AndroidRuntime（1895）：关闭VM 01-17 21：27：33.075：W / dalvikvm（1895）：threadid = 1：线程退出未捕获异常（组= 0xa4be7648） 01-17 21：27：33.075：E / AndroidRuntime（1895）：致命异常：主要 01-17 21：27：33.075：E / AndroidRuntime（1895）：java.lang.IndexOutOfBoundsException：索引0无效，大小为0 01-17 21：27：33.075：E / AndroidRuntime（1895）：at java.util.ArrayList.throwIndexOutOfBoundsException（ArrayList.java:255） 01-17 21：27：33.075：E / AndroidRuntime（1895）：at java.util.ArrayList.get（ArrayList.java:308） 01-17 21：27：33.075：E / AndroidRuntime（1895）：at com.example.gcmclientapp.GcmServer $ 1.onItemSelected（GcmServer.java:123） 01-17 21：27：33.075：E / AndroidRuntime（1895）：在android.widget.AdapterView.fireOnSelected（AdapterView.java:892） 01-17 21：27：33.075：E / AndroidRuntime（1895）：在android.widget.AdapterView.access $ 200（AdapterView.java:49） 01-17 21：27：33.075：E / AndroidRuntime（1895）：在android.widget.AdapterView $ SelectionNotifier.run（AdapterView.java:860） 01-17 21：27：33.075：E / AndroidRuntime（1895）：在android.os.Handler.handleCallback（Handler.java:730） 01-17 21：27：33.075：E / AndroidRuntime（1895）：在android.os.Handler.dispatchMessage（Handler.java:92） 01-17 21：27：33.075：E / AndroidRuntime（1895）：在android.os.Looper.loop（Looper.java:137） 01-17 21：27：33.075：E / AndroidRuntime（1895）：在android.app.ActivityThread.main（ActivityThread.java:5103） 01-17 21：27：33.075：E / AndroidRuntime（1895）：at java.lang.reflect.Method.invokeNative（Native Method） 01-17 21：27：33.075：E / AndroidRuntime（1895）：at java.lang.reflect.Method.invoke（Method.java:525） 01-17 21：27：33.075：E / AndroidRuntime（1895）：at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:737） 01-17 21：27：33.075：E / AndroidRuntime（1895）：at com.android.internal.os.ZygoteInit.main（ZygoteInit.java:553） 01-17 21：27：33.075：E / AndroidRuntime（1895）：at dalvik.system.NativeStart.main（Native Method）

2 个答案:

答案 0 :(得分：0)

尝试将值填充到Spinner中，而不是在任何其他方法中，而是在onCreate（）方法中。尝试按以下方式更改您的计划：

将getTableValues（）方法更改为：

public String[] getTableValues() {

从该方法中删除这些行：

ArrayAdapter my_Adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, arr);

My_spinner.setAdapter(my_Adapter);

并在方法结束处返回数组“arr”; 

return arr;

然后在初始化My_spinner对象后，在onCreate（）方法中将值填充到Spinner，如下所示

My_spinner = (Spinner) findViewById(R.id.spinner1);
arr = getTableValues();
ArrayAdapter my_Adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, arr);

My_spinner.setAdapter(my_Adapter);

答案 1 :(得分：0)

尝试使此代码正常工作，因为我目前无法调试此代码。很高兴能帮到这个...... 

import java.io.BufferedReader;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.StrictMode;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.DatabaseUtils;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemSelectedListener;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

public class GcmServer extends Activity {


     void showToast(CharSequence msg) {
            Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
        }



    // declarations for creating the database
    SQLiteDatabase mydb;
    String name_from_spinner;  // this will be used to filter the database for the required registrationID
    private   static String DBNAME = "new1.db";  // this is our database..change it when you use
    private static String TABLE = "MY_TABLE";
    //end of dec








    EditText et;
    String regId,userName;
    Button b;
    TextView tv,tv2;
    String temp="";
    String[] arr;
    Spinner My_spinner;
    InputStream is=null;

    ArrayList<String> my_array1 = new ArrayList<String>();
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gcmserver);
        b= (Button)findViewById(R.id.button1); 
        et=(EditText)findViewById(R.id.editText1);
        tv=(TextView)findViewById(R.id.textView1);
        tv2=(TextView)findViewById(R.id.textView2);


        regId = getIntent().getStringExtra("REGID");
        userName = getIntent().getStringExtra("USER");



          insertvalues();


          My_spinner = (Spinner) findViewById(R.id.spinner1);

          List<String> list = getTableValues();

          ArrayAdapter my_Adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, list);

          My_spinner.setAdapter(my_Adapter);







        //setting on click listeners for the items of the spinner

        My_spinner.setOnItemSelectedListener(
                new OnItemSelectedListener() {
                    public void onItemSelected(
                        AdapterView<?> parent, View view, int position, long id) {
                        name_from_spinner=my_array1.get(position);
                        showToast(name_from_spinner);// get the name that has been clicked in the spinner





                    }

                    public void onNothingSelected(AdapterView<?> parent) {
                        showToast("Please enter contact");

                    }
                });







        // when the send button is clicked,we will extract the message from editText,regID and send to sendtoserver

        // send button
        b.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {

                String ID = null;
                String REGID=null;
                String NAME=null;
                String message =et.getText().toString(); //extract message from edit text
                // extract registration number
                 try {

                    mydb = openOrCreateDatabase(DBNAME, Context.MODE_PRIVATE, null);
                    Cursor allrows = mydb.rawQuery("SELECT * FROM " + TABLE, null);
                    if (allrows.moveToFirst()) {
                        do {

                             ID = allrows.getString(0);
                             REGID = allrows.getString(1);
                             NAME = allrows.getString(2);
                             if(NAME.equals(name_from_spinner)) // string comparison
                             {

                                 break;
                             }

                        } while (allrows.moveToNext());

                        showToast("left loop");


                    }



                    allrows.close();
                    mydb.close();
                } catch (Exception e) {
                    Toast.makeText(getApplicationContext(), "Error encountered.",
                            Toast.LENGTH_LONG);
                }
                 //tv.setText(REGID);
                 System.out.print(REGID);
                sendToServer(message,REGID);
            }

        }); 

    }



    //#########################################INSERT############################################################
    public void insertvalues()
    {
    StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
    List<NameValuePair> nameValuePairs=new ArrayList<NameValuePair>(1);
    nameValuePairs.add(new BasicNameValuePair("regid", regId));
    nameValuePairs.add(new BasicNameValuePair("name", userName));

    try {
          //tv2.setText(regId);
          HttpClient httpClient=new DefaultHttpClient();
          HttpPost httpPost=new HttpPost("http://192.168.1.3/new.php");
          httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
          HttpResponse response=httpClient.execute(httpPost);
          HttpEntity entity=response.getEntity();
          is=entity.getContent();
          showToast("data inserted successfully");






    }
    catch(ClientProtocolException e)
    {

         Log.e("clientProtocol","Log_tag");
         e.printStackTrace();

    }catch(IOException e)
    {
        Log.e("log_tag","ioexception");
        e.printStackTrace();

    }

    }


    public void sendToServer(final String message,final String ID){
        //tv2.setText(ID);
        new AsyncTask<String, Void, String>(){
        // changes are needed here
        @Override
        protected String doInBackground(String... params) {
            try {
                HttpResponse response = null;
                HttpParams httpParameters = new BasicHttpParams();
                HttpClient client = new DefaultHttpClient(httpParameters);
                String url="http://192.168.1.3/GCM/gcm.php?" + "&regID="+ ID + "&message="+ message; // changes needed here
                Log.i("Send URL:", url);
                HttpGet request = new HttpGet(url);

                response = client.execute(request);
                Log.i("responce URL:"," ");
                BufferedReader rd = new BufferedReader(new InputStreamReader(
                        response.getEntity().getContent()));

                String webServiceInfo = "";
                while ((webServiceInfo = rd.readLine()) != null) {
                    Log.d("****Status Log***", "Webservice: " + webServiceInfo);

                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
   }.execute(null,null,null);
  }
















 // ################################THIS FUNCTION SHOWS DATA FROM THE DATABASE#####################################
    public List<String> getTableValues() {

        InputStream iss=null;
        String line=null;
        String result=null;
        StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);


        try {

              HttpClient httpClient=new DefaultHttpClient();
              HttpPost httpPost=new HttpPost("http://192.168.1.3/retrieve.php");

              HttpResponse response=httpClient.execute(httpPost);
              HttpEntity entity=response.getEntity();
              iss=entity.getContent();


              }
        catch(ClientProtocolException e)
        {

             System.out.println("exception 1  caught");

        }

        catch(IOException e)
        {
            Log.e("log_tag","ioexception");
            e.printStackTrace();

        }

        try{
            BufferedReader reader=new BufferedReader(new InputStreamReader(iss,"iso-8859-1"),8);
            StringBuilder sb=new StringBuilder();
            while((line=reader.readLine())!=null)

                        sb.append(line+"\n");
                        result=sb.toString();
                        //result now contains the data in the form of json
                        iss.close();
                        System.out.println("here is my data");
                        System.out.println(result);




        }
        catch(Exception e)
        {
            System.out.println("exception 2 caught");
        }

        List<String> list = new ArrayList<String>();

        try{

            JSONArray jArray=new JSONArray(result);
            int count=jArray.length();

            for(int i=0;i<count;i++)
            {
                JSONObject json_data=jArray.getJSONObject(i);
                list.add(json_data.getString("name"));
            }
            //System.out.println(temp);
            tv.setText(arr[1]);
            tv2.setText(arr[2]);


        }
        catch(Exception e)
        {
            System.out.println("m so boread");
            //System.out.println("hello");
        }

        return list;

    }

  //###############################################################################################################  
 }
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