I want to upload images from the SD card to the server. So i have idea about back end code i.e is how to upload files. But i want to know how i will provide the user to select images from his device to upload it to the server.how i can create the UI of this application that will ask the user to select a image and upload it?Pleas help me i am new in android. the Image upload logic is like : I got the solution i am using this code ...
  public class DialogFile extends Activity {
    FileDialog fileDialog = null;
    static String fileName="";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.onCreate(savedInstanceState);
        File mPath = new File(Environment.getExternalStorageDirectory() + "//Gaurav-Test//");
        fileDialog = new FileDialog(this, mPath);
        fileDialog.setFileEndsWith(".txt");
        fileDialog.addFileListener(new FileDialog.FileSelectedListener() {
            public void fileSelected(File file) {
                fileName = file.toString();
                Log.d(getClass().getName(), "selected file " + file.toString());
                UploadToServer uploadObj = new UploadToServer();
                try {
                    uploadObj.execute().get();
                } catch (InterruptedException e) {
                    Log.d("InterruptedException", e.getMessage());
                    e.printStackTrace();
                } catch (ExecutionException e) {
                    Log.d("ExecutionException", e.getMessage());
                    e.printStackTrace();
                }
            }
        });
       fileDialog.showDialog();
    }
Then in the file FileDilaog.java
import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Environment;
import android.util.Log;
public class FileDialog {
    private static final String PARENT_DIR = "..";
    private final String TAG = getClass().getName();
    private String[] fileList;
    private File currentPath;
    public interface FileSelectedListener {
        void fileSelected(File file);
    }
    public interface DirectorySelectedListener {
        void directorySelected(File directory);
    }
    private ListenerList<FileSelectedListener> fileListenerList = new ListenerList<FileDialog.FileSelectedListener>();
    private ListenerList<DirectorySelectedListener> dirListenerList = new ListenerList<FileDialog.DirectorySelectedListener>();
    private final Activity activity;
    private boolean selectDirectoryOption;
    private String fileEndsWith;    
    /**
     * @param activity 
     * @param initialPath
     */
    public FileDialog(Activity activity, File path) {
        this.activity = activity;
        if (!path.exists()) path = Environment.getExternalStorageDirectory();
        loadFileList(path);
    }
    /**
     * @return file dialog
     */
    public Dialog createFileDialog() {
        Dialog dialog = null;
        AlertDialog.Builder builder = new AlertDialog.Builder(activity);
        builder.setTitle(currentPath.getPath());
        if (selectDirectoryOption) {
            builder.setPositiveButton("Select directory", new OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    Log.d(TAG, currentPath.getPath());
                    fireDirectorySelectedEvent(currentPath);
                }
            });
        }
        builder.setItems(fileList, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                String fileChosen = fileList[which];
                File chosenFile = getChosenFile(fileChosen);
                if (chosenFile.isDirectory()) {
                    loadFileList(chosenFile);
                    dialog.cancel();
                    dialog.dismiss();
                    showDialog();
                } else fireFileSelectedEvent(chosenFile);
            }
        });
        dialog = builder.show();
        return dialog;
    }
    public void addFileListener(FileSelectedListener listener) {
        fileListenerList.add(listener);
    }
    public void removeFileListener(FileSelectedListener listener) {
        fileListenerList.remove(listener);
    }
    public void setSelectDirectoryOption(boolean selectDirectoryOption) {
        this.selectDirectoryOption = selectDirectoryOption;
    }
    public void addDirectoryListener(DirectorySelectedListener listener) {
        dirListenerList.add(listener);
    }
    public void removeDirectoryListener(DirectorySelectedListener listener) {
        dirListenerList.remove(listener);
    }
    /**
     * Show file dialog
     */
    public void showDialog() {
        createFileDialog().show();
    }
    private void fireFileSelectedEvent(final File file) {
        fileListenerList.fireEvent(new FireHandler<FileDialog.FileSelectedListener>() {
            public void fireEvent(FileSelectedListener listener) {
                listener.fileSelected(file);
            }
        });
    }
    private void fireDirectorySelectedEvent(final File directory) {
        dirListenerList.fireEvent(new FireHandler<FileDialog.DirectorySelectedListener>() {
            public void fireEvent(DirectorySelectedListener listener) {
                listener.directorySelected(directory);
            }
        });
    }
    private void loadFileList(File path) {
        this.currentPath = path;
        List<String> r = new ArrayList<String>();
        if (path.exists()) {
            if (path.getParentFile() != null) r.add(PARENT_DIR);
            FilenameFilter filter = new FilenameFilter() {
                public boolean accept(File dir, String filename) {
                    File sel = new File(dir, filename);
                    if (!sel.canRead()) return false;
                    if (selectDirectoryOption) return sel.isDirectory();
                    else {
                        boolean endsWith = fileEndsWith != null ? filename.toLowerCase().endsWith(fileEndsWith) : true;
                        return endsWith || sel.isDirectory();
                    }
                }
            };
            String[] fileList1 = path.list(filter);
            for (String file : fileList1) {
                r.add(file);
            }
        }
        fileList = (String[]) r.toArray(new String[]{});
    }
    private File getChosenFile(String fileChosen) {
        if (fileChosen.equals(PARENT_DIR)) return currentPath.getParentFile();
        else return new File(currentPath, fileChosen);
    }
    public void setFileEndsWith(String fileEndsWith) {
        this.fileEndsWith = fileEndsWith != null ? fileEndsWith.toLowerCase() : fileEndsWith;
    }
 }
class ListenerList<L> {
private List<L> listenerList = new ArrayList<L>();
public interface FireHandler<L> {
    void fireEvent(L listener);
}
public void add(L listener) {
    listenerList.add(listener);
}
public void fireEvent(FireHandler<L> fireHandler) {
    List<L> copy = new ArrayList<L>(listenerList);
    for (L l : copy) {
        fireHandler.fireEvent(l);
    }
}
public void remove(L listener) {
    listenerList.remove(listener);
}
public List<L> getListenerList() {
    return listenerList;
}
}
Then the HTTPOST code to upload this to the Server
import java.io.File;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import android.os.AsyncTask;
import android.util.Log;
public class UploadToServer extends AsyncTask<String, String, String>{
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }
    @Override
    protected String doInBackground(String... aurl){
        String status="";
        final String URL= "";
        Log.d("Image Path ======",DialogFile.fileName);
        try{
        HttpClient httpclient = new DefaultHttpClient();
         HttpPost httppost = new HttpPost(URL);
         File file = new File(DialogFile.fileName);
         FileBody bin = new FileBody(file);
         MultipartEntity reqEntity = new MultipartEntity();
         reqEntity.addPart("userImage", bin);
         httppost.setEntity(reqEntity);
         Log.d("executing request ",  httppost.getRequestLine().toString());
         HttpResponse response = httpclient.execute(httppost);
         HttpEntity resEntity = response.getEntity();
         if (resEntity != null)
         {
            Log.d("Response content length: ",resEntity.getContentLength()+"");
             if(resEntity.getContentLength()>0)
             {
                status= EntityUtils.toString(resEntity);
             }
             else
             {
                 status= "No Response from Server";
                 Log.d("Status----->",status);
             }
     }
     else
     {
          status= "No Response from Server";
          Log.d("Status----->",status);
     }
        } catch (Exception e) {
                e.printStackTrace();
                status="Unable to connect with iPerform server";
            }
            return status;
        }
}
 
     
     
    