我正在获取图像 URL 并在 GridView 中设置该 URL。它在 Gridview 中成功显示。但我也想使用服务将图像存储在 SDCard 中。如何做到这一点。请有人帮我解决这个问题。谢谢。
public class MainActivity extends Activity {
ListView list;
GridView gv;
String TAG = "GRIDVIEW";
LazyAdapter adapter;
Bitmap bitmap;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startService(new Intent(this, MyService.class));
new loading().execute();
// gv = (GridView) findViewById(R.id.grid_view);
// startService(new Intent(MainActivity.this, MyService.class));
// gv = (GridView) findViewById(R.id.grid_view);
// gv.setAdapter(new LazyAdapter(MainActivity.this, mStrings));
// gv.setHorizontalSpacing(10);
// gv.setVerticalSpacing(40);
// gv.setGravity(200);
}
ProgressDialog mprogress;
private class loading extends AsyncTask<String, Void, String> {
protected void onPreExecute() {
mprogress = new ProgressDialog(MainActivity.this);
mprogress.setMessage("Loading...");
mprogress.show();
super.onPreExecute();
}
protected String doInBackground(String... params) {
// startService(new Intent(MainActivity.this, MyService.class));
return null;
}
protected void onPostExecute(String result) {
getGirdview();
mprogress.dismiss();
super.onPostExecute(result);
}
private void getGirdview() {
gv = (GridView) findViewById(R.id.grid_view);
gv.setAdapter(new LazyAdapter(MainActivity.this, mStrings));
gv.setHorizontalSpacing(10);
gv.setVerticalSpacing(40);
}
}
public String[] mStrings = {
"http://a1.twimg.com/profile_images/97470808/icon_normal.png",
"http://a3.twimg.com/profile_images/511790713/AG.png",
};
}
public class MyService extends Service {
String TAG = "GRIDVIEW";
Bitmap bitmap;
MainActivity mclass = new MainActivity();
public void onStart(Intent intent, int startId) {
for (int i = 0; i < mclass.mStrings.length; i++) {
String str = mclass.mStrings[i];
bitmap = DownloadImage(str);
// Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
// R.drawable.ic_launcher);
// File sd = Environment.getExternalStorageDirectory();
File storagePath = new File(
Environment.getExternalStorageDirectory(), "Wallpaper");
storagePath.mkdirs();
String fileName = "test" + i + ".png";
File dest = new File(storagePath, fileName);
try {
FileOutputStream out;
out = new FileOutputStream(dest);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
out.flush();
out.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
super.onStart(intent, startId);
}
public int onStartCommand(Intent intent, int flags, int startId) {
// for (int i = 0; i < mStrings.length; i++) {
//
// String str = mStrings[i];
// bitmap = DownloadImage(str);
// // Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
// // R.drawable.ic_launcher);
// // File sd = Environment.getExternalStorageDirectory();
// File storagePath = new File(
// Environment.getExternalStorageDirectory(), "Wallpaper");
// storagePath.mkdirs();
//
// String fileName = "test" + i + ".png";
// File dest = new File(storagePath, fileName);
// try {
// FileOutputStream out;
// out = new FileOutputStream(dest);
// bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
// out.flush();
// out.close();
// } catch (FileNotFoundException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }
return super.onStartCommand(intent, flags, startId);
}
public IBinder onBind(Intent intent) {
return null;
}
// public void onStart(Intent intent, int startId) {
//
// for (int i = 0; i < mStrings.length; i++) {
//
// String str = mStrings[i];
// bitmap = DownloadImage(str);
// // Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
// // R.drawable.ic_launcher);
// // File sd = Environment.getExternalStorageDirectory();
// File storagePath = new File(
// Environment.getExternalStorageDirectory(), "Wallpaper");
// storagePath.mkdirs();
//
// String fileName = "test" + i + ".png";
// File dest = new File(storagePath, fileName);
// try {
// FileOutputStream out;
// out = new FileOutputStream(dest);
// bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
// out.flush();
// out.close();
// } catch (FileNotFoundException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }
// super.onStart(intent, startId);
// }
private InputStream OpenHttpConnection(String urlString) throws IOException {
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try {
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
} catch (Exception ex) {
throw new IOException("Error connecting");
}
return in;
}
private Bitmap DownloadImage(String URL) {
Bitmap bitmap = null;
InputStream in = null;
try {
in = OpenHttpConnection(URL);
bitmap = BitmapFactory.decodeStream(in);
in.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Toast.makeText(MyService.this, "Image is Downloaded",
Toast.LENGTH_SHORT).show();
return bitmap;
}
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.ic_launcher;
public void DisplayImage(String url, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else {
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView) {
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Throwable ex) {
ex.printStackTrace();
if (ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
try {
// decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1 = new FileInputStream(f);
BitmapFactory.decodeStream(stream1, null, o);
stream1.close();
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 70;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
FileInputStream stream2 = new FileInputStream(f);
Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
try {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
Activity a = (Activity) photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
} catch (Throwable th) {
th.printStackTrace();
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run() {
if (imageViewReused(photoToLoad))
return;
if (bitmap != null)
photoToLoad.imageView.setImageBitmap(bitmap);
else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
public class LazyAdapter extends BaseAdapter {
private Context mContext;
String TAG = "GridView";
private Activity activity;
private String[] data;
private static LayoutInflater inflater = null;
public ImageLoader imageLoader;
Bitmap bitmap;
public LazyAdapter(Activity a, String[] d) {
activity = a;
data = d;
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
imageLoader = new ImageLoader(activity.getApplicationContext());
}
public int getCount() {
return data.length;
}
public Object getItem(int position) {
return data;
}
public long getItemId(int position) {
return 0;
}
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = inflater.inflate(R.layout.item, null);
}
// TextView txt_name = (TextView) convertView.findViewById(R.id.text);
// txt_name.setText("item" + position);
ImageView image = (ImageView) convertView.findViewById(R.id.image);
// image.setTag(data[position]);
imageLoader.DisplayImage(data[position], image);
return convertView;
}
}