hi,

i am very new in android development as well as in java. i had developed an application that gets an image url from a site and wanted to download it into the device and later on i would like to enable users to set it as wallpapers. however, i am met a problem when assigning onclick event to a button. Once i uncomment the line in red, it will pop up a box stating that the application was stopped unexpectedly. Can someone please help me with this?

private ImageView imView = null;

public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);

try {
/* Create a URL we want to load some xml-data from. */
URL url = new URL(xmlURL);
/* Get a SAXParser from the SAXPArserFactory. */
SAXParserFactory spf = SAXParserFactory.newInstance();
SAXParser sp = spf.newSAXParser();

/* Get the XMLReader of the SAXParser we created. */
XMLReader xr = sp.getXMLReader();
/* Create a new ContentHandler and apply it to the XML-Reader */
ExampleHandler myExampleHandler = new ExampleHandler();
xr.setContentHandler(myExampleHandler);

/* Parse the xml-data from our URL. */
xr.parse(new InputSource(url.openStream()));
/* Parsing has finished. */

/* Our ExampleHandler now provides the parsed data to us. */
ParsedExampleDataSet parsedExampleDataSet = myExampleHandler
.getParsedData();

/* Set the result to be displayed in our GUI. */
if (myExampleHandler.filenames != null) {
a = a + "\n" + myExampleHandler.filenames + ", by "
+ myExampleHandler.authors + "\nhits: "
+ myExampleHandler.hits + " downloads";
this.ed = myExampleHandler.thumbs;
this.imageURL = myExampleHandler.mediafiles;
}
} catch (Exception e) {
a = e.getMessage();
}

// get thumbnail
Context context = this.getBaseContext();
if (ed.length() != 0) {
Drawable image = ImageOperations(context, this.ed, "image.jpg");
ImageView imgView = new ImageView(context);
imgView = (ImageView) findViewById(R.id.image1);
imgView.setImageDrawable(image);
}

TextView tv = (TextView) findViewById(R.id.txt_name);
tv.setText(a);

Button bt3 = (Button) findViewById(R.id.get_imagebt);
//bt3.setOnClickListener(getImageBtnOnClick);
}

OnClickListener getImageBtnOnClick = new OnClickListener() {
public void onClick(View view) {
downloadFile(imageURL);
}
};

void downloadFile(String fileUrl) {
    	URL myFileUrl = null;
    	try {
    		myFileUrl = new URL(fileUrl);
    	} catch (MalformedURLException e) {
    		// TODO Auto-generated catch block
    		e.printStackTrace();
    	}
    	try {
    		HttpURLConnection conn = (HttpURLConnection) myFileUrl
    				.openConnection();
    		conn.setDoInput(true);
    		conn.connect();
    		int length = conn.getContentLength();

    		InputStream is = conn.getInputStream();

    		bmImg = BitmapFactory.decodeStream(is);
    		// this.imView.setImageBitmap(bmImg);
    	} catch (IOException e) {
    		// TODO Auto-generated catch block
    		e.printStackTrace();
    	}
    }

private Drawable ImageOperations(Context ctx, String url,
    		String saveFilename) {
    	try {
    		InputStream is = (InputStream) this.fetch(url);
    		Drawable d = Drawable.createFromStream(is, "src");
    		return d;
    	} catch (MalformedURLException e) {
    		e.printStackTrace();
    		return null;
    	} catch (IOException e) {
    		e.printStackTrace();
    		return null;
    	}
    }
public Object fetch(String address) throws MalformedURLException,
		IOException {
	URL url = new URL(address);
	Object content = url.getContent();
	return content;
}

Main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:id="@+id/viewgroup">
    <ImageView android:id="@+id/image1"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:layout_gravity="center" />
    <ImageView android:id="@+id/image2"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:layout_gravity="center" />
    <TextView android:id="@+id/txt_name"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal" />
    <Button id="@+id/get_imagebt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="xxx Get an image"
        android:layout_gravity="center" />  
    <ImageView id="@+id/imview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center" /> 
</LinearLayout>