Question

I am new to Android and Java.
I have URL of 36 images.
I want to download all those images and display them in grid view.
I’m referring the code below, So please if some one can edit this code to download multiple images. and display in grid view.
The Below code is just taking one URL and downloading image from that
URL.

package com.example.androidhive;

import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class AndroidDownloadFileByProgressBarActivity extends Activity {

// button to show progress dialog
Button btnShowProgress;

// Progress Dialog
private ProgressDialog pDialog;
ImageView my_image;
// Progress dialog type (0 - for Horizontal progress bar)
public static final int progress_bar_type = 0; 

// File url to download
private static String file_url = "http://api.androidhive.info/progressdialog/hive.jpg";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // show progress bar button
    btnShowProgress = (Button) findViewById(R.id.btnProgressBar);
    // Image view to show image after downloading
    my_image = (ImageView) findViewById(R.id.my_image);
    /**
     * Show Progress bar click event
     * */
    btnShowProgress.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // starting new Async Task
            new DownloadFileFromURL().execute(file_url);
        }
    });
}

/**
 * Showing Dialog
 * */
@Override
protected Dialog onCreateDialog(int id) {
    switch (id) {
    case progress_bar_type: // we set this to 0
        pDialog = new ProgressDialog(this);
        pDialog.setMessage("Downloading file. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setMax(100);
        pDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        pDialog.setCancelable(true);
        pDialog.show();
        return pDialog;
    default:
        return null;
    }
}

/**
 * Background Async Task to download file
 * */
class DownloadFileFromURL extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread
     * Show Progress Bar Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        showDialog(progress_bar_type);
    }

    /**
     * Downloading file in background thread
     * */
    @Override
    protected String doInBackground(String... f_url) {
        int count;
        try {
            URL url = new URL(f_url[0]);
            URLConnection conection = url.openConnection();
            conection.connect();
            // this will be useful so that you can show a tipical 0-100% progress bar
            int lenghtOfFile = conection.getContentLength();

            // download the file
            InputStream input = new BufferedInputStream(url.openStream(), 8192);

            // Output stream
            OutputStream output = new FileOutputStream("/sdcard/downloadedfile.jpg");

            byte data[] = new byte[1024];

            long total = 0;

            while ((count = input.read(data)) != -1) {
                total += count;
                // publishing the progress....
                // After this onProgressUpdate will be called
                publishProgress(""+(int)((total*100)/lenghtOfFile));

                // writing data to file
                output.write(data, 0, count);
            }

            // flushing output
            output.flush();

            // closing streams
            output.close();
            input.close();

        } catch (Exception e) {
            Log.e("Error: ", e.getMessage());
        }

        return null;
    }

    /**
     * Updating progress bar
     * */
    protected void onProgressUpdate(String... progress) {
        // setting progress percentage
        pDialog.setProgress(Integer.parseInt(progress[0]));
   }

    /**
     * After completing background task
     * Dismiss the progress dialog
     * **/
    @Override
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after the file was downloaded
        dismissDialog(progress_bar_type);

        // Displaying downloaded image into image view
        // Reading image path from sdcard
        String imagePath = Environment.getExternalStorageDirectory().toString() + "/downloadedfile.jpg";
        // setting downloaded into image view
        my_image.setImageDrawable(Drawable.createFromPath(imagePath));
    }

}
}

Please HELP

Answer 1

i think you should use Universal image loader for display image in gridview.it works perfect!!!