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windows store app read and display image from ziparchive without uncompressing files

am trying to show image directly from zip file without extracting file.
ZipArchiveEntry tumbnail = archive.Entries.Where(s => s.FullName.Equals("coverthumb.png")).FirstOrDefault();
if (tumbnail != null)
{
Stream picdata = tumbnail.Open();
await picdata.CopyToAsync (picdata);
BitmapImage bt = new BitmapImage();
bt.SetSource (picdata.AsRandomAccessStream());
image.Source = bt;
}
but getting an
cannot seek exception
please help.

the following code works for images but when tries to read many images at once some times it gives invalid data exception at bitmap creation
async public static Task<BitmapImage> GetImageFromZipEntry(ZipArchiveEntry zipentry)
{
//for extracting image inside a zip as bitmapimage
BitmapImage tm = new BitmapImage();
try {
if (zipentry != null)
{
using (Stream imstream = zipentry.Open())
{
using (MemoryStream immemorystream = new MemoryStream((int)zipentry.Length))
{
await imstream.CopyToAsync(immemorystream);
using (var sourceStream = new MemoryStream(immemorystream.ToArray()))
{
await tm.SetSourceAsync(sourceStream.AsRandomAccessStream());
}
}
}
}
}
catch(Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.Message);
tm = null;
}
return tm;
}

How to save images from web in Isolated Storage?

In my application I have list of urls to images. And what I need to do is download this images and save them in Isolated Storage.
What I already have:
using (IsolatedStorageFile localFile = IsolatedStorageFile.GetUserStoreForApplication()) {
...
foreach (var item in MyList)
{
Uri uri = new Uri(item.url, UriKind.Absolute);
BitmapImage bitmap = new BitmapImage(uri);
WriteableBitmap wb = new WriteableBitmap(bitmap);
using (IsolatedStorageFileStream fs = localFile.CreateFile(GetFileName(item.url)))//escape file name
{
wb.SaveJpeg(fs, wb.PixelWidth, wb.PixelHeight, 0, 85);
}
}
...
}
This code have place inside function in my App.xaml.cs file. I have tried many solutions, in this one the problem is "Invalid cross-thread access".
How can I make it work?

You get invalid cross-thread access if you create WriteableBitmap on non-UI thread. Ensure that that code is run on the main thread by using Dispatcher:
Deployment.Current.Dispatcher.BeginInvoke(() =>
// ...
);

Solution for this problem is:
foreach (var item in MyList)
{
Uri uri = new Uri(item.url, UriKind.Absolute);
HttpWebRequest request = HttpWebRequest.Create(uri) as HttpWebRequest;
request.BeginGetResponse((ar) =>
{
var response = request.EndGetResponse(ar);
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
using (var stream = response.GetResponseStream())
{
var name = GetFileName(item.url);
if (localFile.FileExists(name))
{
localFile.DeleteFile(name);
}
using (IsolatedStorageFileStream fs = localFile.CreateFile(name))
{
stream.CopyTo(fs);
}
}
});
}, null);
}

#Mateusz Rogulski
You should use WebClient, and i suggest you following solution for your problem. just try.
public string YourMethod(string yoursUri)
{
BitmapImage image=new BitmapImage();
WebClient client = new WebClient();
client.OpenReadCompleted += async (o, args) =>
{
Stream stream = new MemoryStream();
await args.Result.CopyToAsync(stream);
image.SetSource(stream);
};
client.OpenReadAsync(new Uri(yoursUri));//if passing object than you can write myObj.yoursUri
return image;
}
now you have image and you can save into your isolatedStorage with valid checks wherever you call this function

WriteableBitmap memory leak in Windows Phone 8

I'm having a memory leak whenever I create any instance of a WriteableBitmap. I've tried multiple suggestions on stackoverflow and other forums, but nothing is working. The basic flow of my test app is this:
Select an image with the PhotoChooserTask
Use the Stream from the PhotoResult object to create a WriteableBitmap.
That's it. Nulling the variables and calling GC.Collect() only solves part of the problem. It keeps the app from allocating memory until the app crashes, but even though the objects have gone out of scope, there is always memory allocated for them until I select a new image. I can reproduce it with the default Windows Phone Direct3D with XAML App. The only modifications to the default project are the following:
MainPage.xaml.cs
public MainPage() {
InitializeComponent();
_photoChooserTask = new PhotoChooserTask();
_photoChooserTask.Completed += new EventHandler<PhotoResult>(photoChooserTaskComplete);
}
private void ApplicationBarIconButton_Click(object sender, EventArgs e) {
_photoChooserTask.Show();
}
private void photoChooserTaskComplete(object sender, PhotoResult e) {
if (e.TaskResult == TaskResult.OK) {
BitmapImage image = new BitmapImage();
image.SetSource(e.ChosenPhoto);
WriteableBitmap wbm = new WriteableBitmap(image);
image.UriSource = null;
image = null;
wbm = null;
GC.Collect();
}
}
MainPage.xaml
<phone:PhoneApplicationPage.ApplicationBar>
<shell:ApplicationBar IsVisible="True" IsMenuEnabled="True" Mode="Default" Opacity="0.5" >
<shell:ApplicationBar.Buttons>
<shell:ApplicationBarIconButton IconUri="/junkUrl.png" Text="albums" Click="ApplicationBarIconButton_Click" />
</shell:ApplicationBar.Buttons>
</shell:ApplicationBar>
</phone:PhoneApplicationPage.ApplicationBar>

For this you have to store this file stream inside the IsolatedStorege. So create a filestream using IsolatedStorageFileStream and then save it, like this...
private void photoChooserTaskComplete(object sender, PhotoResult e) {
if (e.TaskResult == TaskResult.OK) {
SaveToIsolatedStorage(e.ChosenPhoto,"Your File Name");
}
}
public void SaveToIsolatedStorage(Stream imageStream, string fileName)
{
try
{
string imagename = fileName + ".jpg";
using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
if (myIsolatedStorage.FileExists(imagename))
{
myIsolatedStorage.DeleteFile(imagename);
}
IsolatedStorageFileStream fileStream = myIsolatedStorage.CreateFile(imagename);
WriteableBitmap wb = new WriteableBitmap(100, 100);
wb.SetSource(imageStream);
wb.SaveJpeg(fileStream, 100, 100, 0, 70);
fileStream.Close();
}
}
catch (Exception)
{
RadMessageBox.Show(String.Empty, MessageBoxButtons.OK, "Error occured while saving Images");
}
}
And for reading you can get that file from IsolatedStorage
public WriteableBitmap ReadFromIsolatedStorage(string fileName)
{
WriteableBitmap bitmap = new WriteableBitmap(100, 100);
try
{
using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
if (myIsolatedStorage.FileExists(fileName))
{
using (IsolatedStorageFileStream fileStream = myIsolatedStorage.OpenFile(fileName, FileMode.Open, FileAccess.Read))
{
// Decode the JPEG stream.
bitmap = PictureDecoder.DecodeJpeg(fileStream, 100, 100);
}
}
}
}
catch (Exception)
{
RadMessageBox.Show(String.Empty, MessageBoxButtons.OK, "Error Occcured while reading image");
}
return bitmap;
}
This will solved your memory leak problem, try this...

System.InvalidOperationException occur when load saved Image from IsolatedStorage

I have found a class from the link ImageCaching
but when i load from isolated storage i got an exeption "System.InvalidOperationException"
here is my code
public static object DownloadFromWeb(Uri imageFileUri)
{
WebClient m_webClient = new WebClient(); //Load from internet
BitmapImage bm = new BitmapImage();
m_webClient.OpenReadCompleted += (o, e) =>
{
if (e.Error != null || e.Cancelled) return;
WriteToIsolatedStorage(IsolatedStorageFile.GetUserStoreForApplication(), e.Result, GetFileNameInIsolatedStorage(imageFileUri));
bm.SetSource(e.Result);
e.Result.Close();
};
m_webClient.OpenReadAsync(imageFileUri);
return bm;
}
public static object ExtractFromLocalStorage(Uri imageFileUri)
{
byte[] data;
string isolatedStoragePath = GetFileNameInIsolatedStorage(imageFileUri); //Load from local storage
if (null == _storage)
{
_storage = IsolatedStorageFile.GetUserStoreForApplication();
}
using (IsolatedStorageFileStream sourceFile = _storage.OpenFile(isolatedStoragePath, FileMode.Open, FileAccess.Read))
{
// Read the entire file and then close it
sourceFile.Read(data, 0, data.Length);
sourceFile.Close();
BitmapImage bm = new BitmapImage();
bm.SetSource(sourceFile);///here got the exeption
return bm;
}
}
so that i can't set the image.

I'm using the converter you mentioned and it works but you modified the method.
Your ExtractFromLocalStorage method isn't the same. You close your stream before to use it with the SetSource method.
Here is the original method code:
private static object ExtractFromLocalStorage(Uri imageFileUri)
{
string isolatedStoragePath = GetFileNameInIsolatedStorage(imageFileUri); //Load from local storage
using (var sourceFile = _storage.OpenFile(isolatedStoragePath, FileMode.Open, FileAccess.Read))
{
BitmapImage bm = new BitmapImage();
bm.SetSource(sourceFile);
return bm;
}
}

Save a remote image in to Isolated Storage

I tried using this code for download image:
void downloadImage(){
WebClient client = new WebClient();
client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
client.DownloadStringAsync(new Uri("http://mysite/image.png"));
}
void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
//how get stream of image??
PicToIsoStore(stream)
}
private void PicToIsoStore(Stream pic)
{
using (var isoStore = IsolatedStorageFile.GetUserStoreForApplication())
{
var bi = new BitmapImage();
bi.SetSource(pic);
var wb = new WriteableBitmap(bi);
using (var isoFileStream = isoStore.CreateFile("somepic.jpg"))
{
var width = wb.PixelWidth;
var height = wb.PixelHeight;
Extensions.SaveJpeg(wb, isoFileStream, width, height, 0, 100);
}
}
}
The problem is: how get the stream of image?
Thank!

It's easy to get a stream to a file in Isolated Storage. IsolatedStorageFile has an OpenFile method that gets one.
using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication())
{
using (IsolatedStorageFileStream stream = store.OpenFile("somepic.jpg", FileMode.Open))
{
// do something with the stream
}
}

You need to put e.Result as a parameter when calling PicToIsoStore inside your client_DownloadStringCompleted method
void client_DownloadStringCompleted(object sender,
DownloadStringCompletedEventArgs e)
{
PicToIsoStore(e.Result);
}
The WebClient class gets response and stores it in the e.Result variable. If you look carefully, the type of e.Result is already Stream so it is ready to be passed to your method PicToIsoStore

There is an easy way
WebClient client = new WebClient();
client.OpenReadCompleted += (s, e) =>
{
PicToIsoStore(e.Result);
};
client.OpenReadAsync(new Uri("http://mysite/image.png", UriKind.Absolute));

Try the following
public static Stream ToStream(this Image image, ImageFormat formaw) {
var stream = new System.IO.MemoryStream();
image.Save(stream);
stream.Position = 0;
return stream;
}
Then you can use the following
var stream = myImage.ToStream(ImageFormat.Gif);