问题
hi to all i have this problem with my code and i tried every thing that i know of and i posted it on some forums and didnt get an answer im new to android and im still learning .....
my question is that i have a code that is suppose to receive a variable that contains a website that has an image so this variable changes every time i send a new link this code should go online and download the image and save it to the sd-card then i read it and display it
so my problem with the code is if im sending 2 links to it, it downloads 1 of the images and it always stores it with the second image name (example: im sending image1 and image2 the code downloads image1 two times and stores it as "image2") when i mount the sd-card and check the image directory there is only 1 image there named image2,
i thought that doInBackground was causing the problem but im also using onPostExecute()
so please if someone can help me i would be thankful for his help
Note this is how i call it:
locLink = getLocalLink(buffer[3], buffer[0]);
buffer[3] = image website (example:http://www.oceanwideimages.com/images/7049/large/24M2444-16-palm-fringed-tropical-island.jpg)
buffer[0] = new file name (example 1 as a string)
this is the code:
private class DownloadImageTask extends AsyncTask<URL, Integer, Bitmap> {
// This class definition states that DownloadImageTask will take String
// parameters, publish Integer progress updates, and return a Bitmap
protected Bitmap doInBackground(URL... paths) {
URL url;
try {
url = paths[0];
HttpURLConnection connection = (HttpURLConnection) url
.openConnection();
int length = connection.getContentLength();
InputStream is = (InputStream) url.getContent();
byte[] imageData = new byte[length];
int buffersize = (int) Math.ceil(length / (double) 100);
int downloaded = 0;
int read;
while (downloaded < length) {
if (length < buffersize) {
read = is.read(imageData, downloaded, length);
} else if ((length - downloaded) <= buffersize) {
read = is.read(imageData, downloaded, length
- downloaded);
} else {
read = is.read(imageData, downloaded, buffersize);
}
downloaded += read;
publishProgress((downloaded * 100) / length);
}
Bitmap bitmap = BitmapFactory.decodeByteArray(imageData, 0,
length);
if (bitmap != null) {
Log.i(TAG, "Bitmap created");
} else {
Log.i(TAG, "Bitmap not created");
}
is.close();
return bitmap;
} catch (MalformedURLException e) {
Log.e(TAG, "Malformed exception: " + e.toString());
} catch (IOException e) {
Log.e(TAG, "IOException: " + e.toString());
} catch (Exception e) {
Log.e(TAG, "Exception: " + e.toString());
}
return null;
}
protected void onPostExecute(Bitmap result) {
String name = ImageLink.substring(ImageLink
.lastIndexOf("/") + 1);
if (result != null) {
hasExternalStoragePublicPicture(name);
saveToSDCard(result, name);
isImage = true;
} else {
isImage = false;
}
}
}
public void saveToSDCard(Bitmap bitmap, String name) {
boolean mExternalStorageAvailable = false;
boolean mExternalStorageWriteable = false;
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
mExternalStorageAvailable = mExternalStorageWriteable = true;
Log.v(TAG, "SD Card is available for read and write "
+ mExternalStorageAvailable + mExternalStorageWriteable);
saveFile(bitmap, name);
} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
mExternalStorageAvailable = true;
mExternalStorageWriteable = false;
Log.v(TAG, "SD Card is available for read "
+ mExternalStorageAvailable);
} else {
mExternalStorageAvailable = mExternalStorageWriteable = false;
Log.v(TAG, "Please insert a SD Card to save your image "
+ mExternalStorageAvailable + mExternalStorageWriteable);
}
}
private void saveFile(Bitmap bitmap, String name) {
String filename = name;
ContentValues values = new ContentValues();
File sdImageMainDirectory = new File(Environment
.getExternalStorageDirectory(), getResources().getString(
R.string.directory));
sdImageMainDirectory.mkdirs();
File outputFile = new File(sdImageMainDirectory, filename);
values.put(MediaStore.MediaColumns.DATA, outputFile.toString());
values.put(MediaStore.MediaColumns.TITLE, filename);
values.put(MediaStore.MediaColumns.DATE_ADDED, System
.currentTimeMillis());
values.put(MediaStore.MediaColumns.MIME_TYPE, "image/png");
Uri uri = this.getContentResolver().insert(
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
values);
try {
OutputStream outStream = this.getContentResolver()
.openOutputStream(uri);
bitmap.compress(Bitmap.CompressFormat.PNG, 95, outStream);
outStream.flush();
outStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private boolean hasExternalStoragePublicPicture(String name) {
File sdImageMainDirectory = new File(Environment
.getExternalStorageDirectory(), getResources().getString(
R.string.directory));
File file = new File(sdImageMainDirectory, name);
if (file != null) {
file.delete();
}
return file.exists();
}
and this is how i read it:
String imageInSD = c.getString(5); //"/sdcard/Hanud/image1.jpg"or image2;
Bitmap bitmap = BitmapFactory.decodeFile(imageInSD);
myImageView=(ImageView)findViewById(R.id.imageview1);
myImageView.setImageURI(null);
myImageView.setImageBitmap(bitmap);
来源：https://stackoverflow.com/questions/5766430/android-download-image-to-sd-card-and-then-read-it-from-sd-card