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POButton linking to a new page, doesn't work
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  1. POButton linking to a new page, doesn't work
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    copied!<p>I am creating a program that is supposed to show an RSS Feed once a button is clicked.</p> <p>I have a main class, a Screen 1, and Screen 2 and a main xml file and screen 1 and screen 2 in the layout.</p> <p>Now I tried before with the main xml and class being the RSS Feed and it worked fine</p> <p>However, now when I try to make Screen1 (screen1) the place where the feed is displayed, I just get a black screen.</p> <p>I am wondering why this is happening, as I told by Screen1 class to link to the screen1 xml file.</p> <p>Main Class:</p> <pre><code>import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class SImpleRssReader2Activity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button videoNext = (Button) findViewById(R.id.videoButton) ; videoNext.setOnClickListener(new OnClickListener() { public void onClick(View v) { setContentView(R.layout.screen2); // Intent i = new Intent(); // i.setClassName("rahul.application.WunApp", "rahul.application.WunApp.screen1"); // startActivity(i); } }); Button newsNext = (Button) findViewById(R.id.newsButton); newsNext.setOnClickListener(new OnClickListener() { public void onClick(View v) { setContentView(R.layout.screen1); // Intent i = new Intent(); // i.setClassName("rahul.application.WunApp", "rahul.application.WunApp.screen1"); // startActivity(i); } }); } } </code></pre> <p>Screen 1:</p> <pre><code> import java.io.IOException; import java.io.InputStream; import java.net.MalformedURLException; import java.net.URL; import java.util.ArrayList; import java.util.List; import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import org.xmlpull.v1.XmlPullParserFactory; import android.app.ListActivity; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.view.View; import android.widget.ArrayAdapter; import android.widget.ListView; public class Screen1 extends ListActivity { /** Called when the activity is first created. */ List&lt;String&gt; headlines; List&lt;String&gt; links; @Override protected void onListItemClick(ListView l, View v, int position, long id) { Uri uri = Uri.parse((String) links.get(position)); Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent); } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.screen1); // Initializing instance variables headlines = new ArrayList&lt;String&gt;(); links = new ArrayList&lt;String&gt;(); try { URL url = new URL("http://news.google.com/news?ned=us&amp;topic=h&amp;output=rss"); XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); factory.setNamespaceAware(false); XmlPullParser xpp = factory.newPullParser(); // We will get the XML from an input stream xpp.setInput(getInputStream(url), "UTF_8"); /* We will parse the XML content looking for the "&lt;title&gt;" tag which appears inside the "&lt;item&gt;" tag. * However, we should take in consideration that the rss feed name also is enclosed in a "&lt;title&gt;" tag. * As we know, every feed begins with these lines: "&lt;channel&gt;&lt;title&gt;Feed_Name&lt;/title&gt;...." * so we should skip the "&lt;title&gt;" tag which is a child of "&lt;channel&gt;" tag, * and take in consideration only "&lt;title&gt;" tag which is a child of "&lt;item&gt;" * * In order to achieve this, we will make use of a boolean variable. */ boolean insideItem = false; // Returns the type of current event: START_TAG, END_TAG, etc.. int eventType = xpp.getEventType(); while (eventType != XmlPullParser.END_DOCUMENT) { if (eventType == XmlPullParser.START_TAG) { if (xpp.getName().equalsIgnoreCase("item")) { insideItem = true; } else if (xpp.getName().equalsIgnoreCase("title")) { if (insideItem) headlines.add(xpp.nextText()); //extract the headline } else if (xpp.getName().equalsIgnoreCase("link")) { if (insideItem) links.add(xpp.nextText()); //extract the link of article } }else if(eventType==XmlPullParser.END_TAG &amp;&amp; xpp.getName().equalsIgnoreCase("item")){ insideItem=false; } eventType = xpp.next(); //move to next element } } catch (MalformedURLException e) { e.printStackTrace(); } catch (XmlPullParserException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } // Binding data ArrayAdapter&lt;String&gt; adapter = new ArrayAdapter&lt;String&gt;(this, android.R.layout.simple_list_item_1, headlines); setListAdapter(adapter); } public InputStream getInputStream(URL url) { try { return url.openConnection().getInputStream(); } catch (IOException e) { return null; } } </code></pre> <p>Main xml:</p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" &gt; &lt;EditText android:id="@+id/editText1" android:layout_width="match_parent" android:layout_height="wrap_content" android:ems="10" android:text="@string/welcome" &gt; &lt;requestFocus /&gt; &lt;/EditText&gt; &lt;TextView android:id="@+id/textView5" android:layout_width="wrap_content" android:layout_height="wrap_content" /&gt; &lt;TextView android:id="@+id/textView6" android:layout_width="wrap_content" android:layout_height="wrap_content" /&gt; &lt;TextView android:id="@+id/textView7" android:layout_width="wrap_content" android:layout_height="wrap_content" /&gt; &lt;RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" &gt; &lt;Button android:id="@+id/newsButton" android:layout_width="152dp" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:text="@string/button1" /&gt; &lt;/RelativeLayout&gt; &lt;TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" /&gt; &lt;TextView android:id="@+id/textView4" android:layout_width="wrap_content" android:layout_height="wrap_content" /&gt; &lt;RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" &gt; &lt;TextView android:id="@+id/textView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentTop="true" /&gt; &lt;/RelativeLayout&gt; &lt;RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" &gt; &lt;/RelativeLayout&gt; &lt;RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" &gt; &lt;Button android:id="@+id/videoButton" android:layout_width="156dp" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:text="@string/button3" /&gt; &lt;/RelativeLayout&gt; &lt;/LinearLayout&gt; </code></pre> <p>screen1 xml:</p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" &gt; &lt;ListView android:id="@+android:id/list" android:layout_width="fill_parent" android:layout_height="wrap_content" &gt; &lt;/ListView&gt; &lt;/LinearLayout&gt; </code></pre> <p>So to summarize: It worked when I just had the main class and xml, but now that I am linking to a new class and xml, it doesn't work. Why?</p>
 

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