Java 从MainActivity填充第二个活动列表视图

我想用url填充secondActivity中的listview当url中的数据被下载时，我尝试了不同的方法，但没有任何效果

MainActivity.java

    public class MainActivity extends ActionBarActivity {

private static final String DEBUG_TAG = "HttpExample";
private EditText urlText;
private TextView textView;
SharedPreferences.Editor fd;
SharedPreferences FeedPref;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    urlText = (EditText) findViewById(R.id.myurl);
    textView = (TextView) findViewById(R.id.mytext);
    textView.setMovementMethod(ScrollingMovementMethod.getInstance());
    FeedPref=PreferenceManager.getDefaultSharedPreferences(getBaseContext());
    fd=FeedPref.edit(); 



}


public void  myClickHandler(View view) {




    // Gets the URL from the UI's text field.
    String stringUrl = urlText.getText().toString();
    ConnectivityManager connMgr = (ConnectivityManager) 
        getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
    if (networkInfo != null && networkInfo.isConnected()) {


        new DownloadWebpageTask().execute(stringUrl);

    } else {
        textView.setText("No network connection available.");
    }
}



 public class DownloadWebpageTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {



            // params comes from the execute() call: params[0] is the url.
            try {
                return downloadUrl(urls[0]);
            } catch (IOException e) {
                return "Unable to retrieve web page. URL may be invalid.";
            }
        }


       // onPostExecute displays the results of the AsyncTask.
        @Override
        protected void onPostExecute(String result) {
            textView.setText(result);   
            if (result != null  )
            {
           FeedPref=PreferenceManager.getDefaultSharedPreferences(getBaseContext());
           fd=FeedPref.edit();
         String url =urlText.getText().toString(); 
         fd.putString("urls", url);
         fd.commit(); }



       }
    }

 private String downloadUrl(String myurl) throws IOException {
        InputStream is = null;


        try {
            URL url = new URL(myurl);
            HttpURLConnection connect = (HttpURLConnection) url.openConnection();
            connect.setReadTimeout(10000 /* milliseconds */);
            connect.setConnectTimeout(15000 /* milliseconds */);
            connect.setRequestMethod("GET");
            connect.setDoInput(true);
            // Starts the query
            connect.connect();
            int response = connect.getResponseCode();
            Log.d(DEBUG_TAG, "The response is: " + response);
            is = connect.getInputStream();

            // Convert the InputStream into a string
            String contentAsString = readIt(is);
            return contentAsString;

        // Makes sure that the InputStream is closed after the app is
        // finished using it.
        } finally {
            if (is != null) {
                is.close();
            } 
        }
 }

// Reads an InputStream and converts it to a String.
 public String readIt(InputStream stream) throws IOException, UnsupportedEncodingException {
     if (stream != null) {
         StringBuilder sb = new StringBuilder();
         String line;

         try {
             BufferedReader reader = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
             while ((line = reader.readLine()) != null) {
                 sb.append(line);
             }
         } finally {
             stream.close();
         }
         return sb.toString();
     } else {        
         return "";
     }
 }
 public void myClickHandler1(View povijest){
     Intent intent = new Intent(MainActivity.this, SecondActivity.class);
     startActivity(intent);      

 }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

package com.example.networking;

import java.util.ArrayList;

import android.support.v7.app.ActionBarActivity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class SecondActivity extends ActionBarActivity {
        String[] urls1;
        ListView listView;
        ArrayAdapter<String> adapter;
        SharedPreferences FeedPref;
        SharedPreferences.Editor fd;
        TextView txt1;



    protected void onCreate(Bundle savedInstanceState) {
        FeedPref=PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        String  urlsa=FeedPref.getString("urls",null);
          String[] values = new String[] {urlsa,};
          ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, android.R.id.text1, values);



listView.setAdapter(adapter);

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.second, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

公共类MainActivity扩展了ActionBarActivity{
私有静态最终字符串DEBUG_TAG=“HttpExample”；
私人编辑文本；
私有文本视图文本视图；
编辑器fd；
共享参考FeedPref；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
urlText=（EditText）findViewById（R.id.myurl）；
textView=（textView）findViewById（R.id.mytext）；
textView.setMovementMethod（ScrollingMovementMethod.getInstance（））；
FeedPref=PreferenceManager.GetDefaultSharedReferences（getBaseContext（））；
fd=FeedPref.edit（）；
}
公共作废myClickHandler（视图）{
//从UI的文本字段获取URL。
字符串stringUrl=urlText.getText（）.toString（）；
ConnectivityManager connMgr=（ConnectivityManager）
getSystemService（Context.CONNECTIVITY\u服务）；
NetworkInfo NetworkInfo=connMgr.getActiveNetworkInfo（）；
if（networkInfo！=null&&networkInfo.isConnected（））{
新建下载WebPagetAsk（）.execute（stringUrl）；
}否则{
setText（“没有可用的网络连接”）；
}
}
公共类下载WebPagetTask扩展异步任务{
@凌驾
受保护的字符串doInBackground（字符串…URL）{
//params来自execute（）调用：params[0]是url。
试一试{
返回下载URL（URL[0]）；
}捕获（IOE异常）{
return“无法检索网页。URL可能无效。”；
}
}
//onPostExecute显示异步任务的结果。
@凌驾
受保护的void onPostExecute（字符串结果）{
setText（结果）；
如果（结果！=null）
{
FeedPref=PreferenceManager.GetDefaultSharedReferences（getBaseContext（））；
fd=FeedPref.edit（）；
字符串url=urlText.getText（）.toString（）；
putString（“url”，url）；
fd.commit（）；}
}
}
私有字符串下载URL（字符串myurl）引发IOException{
InputStream=null；
试一试{
URL=新URL（myurl）；
HttpURLConnection connect=（HttpURLConnection）url.openConnection（）；
connect.setReadTimeout（10000/*毫秒*/）；
setConnectTimeout（15000/*毫秒*/）；
connect.setRequestMethod（“GET”）；
connect.setDoInput（true）；
//启动查询
connect.connect（）；
int response=connect.getResponseCode（）；
Log.d（DEBUG_标记，“响应为：”+response）；
is=connect.getInputStream（）；
//将InputStream转换为字符串
字符串contentAsString=readIt（is）；
返回contentAsString；
//确保在应用程序启动后关闭InputStream
//用完了。
}最后{
如果（is！=null）{
is.close（）；
} 
}
}
//读取InputStream并将其转换为字符串。
公共字符串readIt（InputStream流）引发IOException，UnsupportedEncodingException{
if（流！=null）{
StringBuilder sb=新的StringBuilder（）；
弦线；
试一试{
BufferedReader=新的BufferedReader（新的InputStreamReader（流，“UTF-8”））；
而（（line=reader.readLine（））！=null）{
某人附加（行）；
}
}最后{
stream.close（）；
}
使某人返回字符串（）；
}否则{
返回“”；
}
}
公共作废myClickHandler1（查看povijest）{
意向意向=新意向（MainActivity.this，SecondActivity.class）；
星触觉（意向）；
}
@凌驾
公共布尔onCreateOptions菜单（菜单）{
//为菜单充气；这会将项目添加到操作栏（如果存在）。
getMenuInflater（）.充气（R.menu.main，menu）；
返回true；
}

}

secondactivity.java

    public class MainActivity extends ActionBarActivity {

private static final String DEBUG_TAG = "HttpExample";
private EditText urlText;
private TextView textView;
SharedPreferences.Editor fd;
SharedPreferences FeedPref;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    urlText = (EditText) findViewById(R.id.myurl);
    textView = (TextView) findViewById(R.id.mytext);
    textView.setMovementMethod(ScrollingMovementMethod.getInstance());
    FeedPref=PreferenceManager.getDefaultSharedPreferences(getBaseContext());
    fd=FeedPref.edit(); 



}


public void  myClickHandler(View view) {




    // Gets the URL from the UI's text field.
    String stringUrl = urlText.getText().toString();
    ConnectivityManager connMgr = (ConnectivityManager) 
        getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
    if (networkInfo != null && networkInfo.isConnected()) {


        new DownloadWebpageTask().execute(stringUrl);

    } else {
        textView.setText("No network connection available.");
    }
}



 public class DownloadWebpageTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {



            // params comes from the execute() call: params[0] is the url.
            try {
                return downloadUrl(urls[0]);
            } catch (IOException e) {
                return "Unable to retrieve web page. URL may be invalid.";
            }
        }


       // onPostExecute displays the results of the AsyncTask.
        @Override
        protected void onPostExecute(String result) {
            textView.setText(result);   
            if (result != null  )
            {
           FeedPref=PreferenceManager.getDefaultSharedPreferences(getBaseContext());
           fd=FeedPref.edit();
         String url =urlText.getText().toString(); 
         fd.putString("urls", url);
         fd.commit(); }



       }
    }

 private String downloadUrl(String myurl) throws IOException {
        InputStream is = null;


        try {
            URL url = new URL(myurl);
            HttpURLConnection connect = (HttpURLConnection) url.openConnection();
            connect.setReadTimeout(10000 /* milliseconds */);
            connect.setConnectTimeout(15000 /* milliseconds */);
            connect.setRequestMethod("GET");
            connect.setDoInput(true);
            // Starts the query
            connect.connect();
            int response = connect.getResponseCode();
            Log.d(DEBUG_TAG, "The response is: " + response);
            is = connect.getInputStream();

            // Convert the InputStream into a string
            String contentAsString = readIt(is);
            return contentAsString;

        // Makes sure that the InputStream is closed after the app is
        // finished using it.
        } finally {
            if (is != null) {
                is.close();
            } 
        }
 }

// Reads an InputStream and converts it to a String.
 public String readIt(InputStream stream) throws IOException, UnsupportedEncodingException {
     if (stream != null) {
         StringBuilder sb = new StringBuilder();
         String line;

         try {
             BufferedReader reader = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
             while ((line = reader.readLine()) != null) {
                 sb.append(line);
             }
         } finally {
             stream.close();
         }
         return sb.toString();
     } else {        
         return "";
     }
 }
 public void myClickHandler1(View povijest){
     Intent intent = new Intent(MainActivity.this, SecondActivity.class);
     startActivity(intent);      

 }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

package com.example.networking;

import java.util.ArrayList;

import android.support.v7.app.ActionBarActivity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class SecondActivity extends ActionBarActivity {
        String[] urls1;
        ListView listView;
        ArrayAdapter<String> adapter;
        SharedPreferences FeedPref;
        SharedPreferences.Editor fd;
        TextView txt1;



    protected void onCreate(Bundle savedInstanceState) {
        FeedPref=PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        String  urlsa=FeedPref.getString("urls",null);
          String[] values = new String[] {urlsa,};
          ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, android.R.id.text1, values);



listView.setAdapter(adapter);

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.second, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

package com.example.networking；
导入java.util.ArrayList；
导入android.support.v7.app.ActionBarActivity；
导入android.content.Context；
导入android.content.Intent；
导入android.content.SharedReferences；
导入android.os.Bundle；
导入android.preference.PreferenceManager；
导入android.view.Menu；
导入android.view.MenuItem；
导入android.widget.ArrayAdapter；
导入android.widget.ListView；
导入android.widget.TextView；
公共类SecondActivity扩展了ActionBarActivity{
字符串[]urls1；
列表视图列表视图；
阵列适配器；
共享参考FeedPref；
编辑器fd；
TextView txt1；
创建时受保护的void（Bundle savedInstanceState）{
FeedPref=PreferenceManager.GetDefaultSharedReferences（getBaseContext（））；
字符串urlsa=FeedPref.getString（“URL”，null）；
字符串[]值=新字符串[]{urlsa，}；
ArrayAdapter=新的ArrayAdapter（这个，android.R.layout.simple_list_item_1，android.R.id.text1，值）；
setAdapter（适配器）；
}
@凌驾
公共布尔onCreateOptions菜单（菜单）{
//为菜单充气；这会将项目添加到操作栏（如果存在）。
getMenuInflater（）.充气（R.menu.second，menu）；
返回true；
}
@凌驾
公共布尔值onOptionsItemSelected（菜单项项）{
//处理操作栏项目单击此处。操作栏将
//自动处理Home/Up按钮上的点击，只要
//在AndroidManifest.xml中指定父活动时。
int id=item.getItemId（）；
if（id==R.id.action\u设置）{
返回true；
protected void onCreate(Bundle savedInstanceState, String urls)

 public void myClickHandler1(View povijest){
     Intent intent = new Intent(MainActivity.this, SecondActivity.class);
     startActivity(intent);      

 }

 public void myClickHandler1(View povijest){
     Intent intent = new Intent(MainActivity.this, SecondActivity.class);
     intent.putExtra("URL", urlText.getText().toString());
     startActivity(intent);      

 }

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_second);
    list = (ListView) findViewById(R.id.lista);
    arrayList = new ArrayList<String>();

    // Adapter: You need three parameters 'the context, id of the layout (it will be where the data is shown),
    // and the array that contains the data
    adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, arrayList);
    // Here, you set the data in your ListView
    list.setAdapter(adapter);

    arrayList.add(getIntent().getStringExtra("URL"));

    adapter.notifyDataSetChanged();
}