views:

311

answers:

2

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>
A: 

Hi!
Please, check catlog view for an error messages. If it's nullPointerException then maybe button of id "get_imagebt" is not a part of a file that you set as a content view? Could you also post your main.xml layout file?
Regards!

Ramps
i had check the catlog and i found a nullPointerException. thus, how can i fix it? Thanks a lot for your help.
Lynnooi
A: 

The code you posted does not show the downloadFile() function; it would help if you paste it too. Also, can you specify the exception that you are getting(check logcat)?

A problem, that I can think of, could be missing INTERNET permission in your manifest file.

Samuh
i had added the download file function. For the INTERNET permission i had already include it in my manifest file. I am able to get the data needed from remote site.
Lynnooi