WinRT: How to read images from the pictures library via an URI? - windows-phone-8

Trying to read an image that is stored in the pictures library via an URI the image is never displayed (in an Image control). Reading the same image via a stream works (assuming the app hat the Picture Library capability declared of course). Reading images from the application's data folder via an URI works.
Does someone know what could be wrong?
Here is how I (unsucessfully) try to read an image via an URI:
var imageFile = (await KnownFolders.PicturesLibrary.GetFilesAsync()).FirstOrDefault();
string imagePath = imageFile.Path;
Uri uriSource = new Uri(imagePath);
var bitmap = new BitmapImage(uriSource);
this.Image.Source = bitmap;
Here is how I sucessfully read the same image via a stream:
var imageFile = (await KnownFolders.PicturesLibrary.GetFilesAsync()).FirstOrDefault();
BitmapImage bitmap;
using (var stream = await imageFile.OpenReadAsync())
{
bitmap = new BitmapImage();
await bitmap.SetSourceAsync(stream);
}
this.Image.Source = bitmap;
I need to read the image via URI because this is the fastest way to read images and is async by nature, working perfectly with data binding.

There is no URI for the pictures library. You'll need to get the StorageFile and stream it in.
The file URI you use doesn't work because the app doesn't have direct access to the PicturesLibrary and so cannot reference items there by path. The StorageFile object provides brokered access to locations that the app doesn't natively have permissions to.

Related

save webcam captured image into local folder without using FileSavePicker

I am using Below Code to save image but it save image after filesavepicker save image but I want to save image direct into local folder without using
filesavepicker,Please suggest me any Solution for this, thanks in Advance.
webcam private async Task SavePhoto(IRandomAccessStream mediaStream)
{
FileSavePicker photoSavePicker = new FileSavePicker();
photoSavePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
var mediaFile = await photoSavePicker.PickSaveFileAsync();
await SaveStreamToFileAsync(mediaStream, mediaFile);
}
I want to save this stream data in image format direct to local folder without using filesavepicker.
Create the StorageFile inside the app's LocalData. Then pass this StorageFile to your function.
StorageFolder dirLocal = Windows.Storage.ApplicationData.Current.LocalFolder;
StorageFile mediaFile = await dirLocal.CreateFileAsync("mediaFile.abc");
SaveStreamToFileAsync(mediaStream, mediaFile);

converting a file path to a URI

When using the secondaryTitle in c++, I have to enter a URI that points to the logo. The URI fails if I try to point it to any file outside of the app's package. What I tried to is have the user select the file using a filepicker
void App3::MainPage::FindLogo(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
FileOpenPicker^ openPicker = ref new FileOpenPicker();
openPicker->ViewMode = PickerViewMode::Thumbnail;
openPicker->SuggestedStartLocation = PickerLocationId::PicturesLibrary;
openPicker->FileTypeFilter->Append(".jpg");
openPicker->FileTypeFilter->Append(".jpeg");
openPicker->FileTypeFilter->Append(".png");
create_task(openPicker->PickSingleFileAsync()).then([this](Windows::Storage::StorageFile^ file)
{
if (file)
{
StorageFolder^ folder;
auto ur = ref new Uri("ms-appx:///Assets//");
String^ s = Windows::ApplicationModel::Package::Current->InstalledLocation->Path;
create_task(StorageFolder::GetFolderFromPathAsync(s)).then([=](StorageFolder^ folder){
create_task(file->CopyAsync(folder, file->Name, NameCollisionOption::ReplaceExisting)).then([this, file](task<StorageFile^> task)
{
logoFile = ref new Uri("ms-appdata:///local//App3//Assets//StoreLogo.scale-100.png");
});
});
}
});
}
then copy that file and save it in the app directory. It still fails when using a uri to point to the new copy.
void App3::MainPage::kk(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
text = url->Text->ToString();
ids = id->Text->ToString();
auto test = ref new Windows::UI::StartScreen::SecondaryTile(ids, "hi", text, logoFile, Windows::UI::StartScreen::TileSize::Square150x150); // Breaks right here
// error: logofile is 0x05fcc1d0
num++;
test->RequestCreateAsync();
//auto uri = ref new Windows::Foundation::Uri("http://www.google.com");
//concurrency::task<bool> launchUriOperation(Windows::System::Launcher::LaunchUriAsync(uri));
}
UPDATED
create_task(openPicker->PickSingleFileAsync()).then([this](Windows::Storage::StorageFile^ file)
{
if (file)
{
StorageFolder^ folder = ApplicationData::Current->LocalFolder;
create_task(file->CopyAsync(folder, file->Name, NameCollisionOption::ReplaceExisting)).then([this, file](task<StorageFile^> task)
{
String^ path = "ms-appdata:///local/" + file->Name;
logoFile = ref new Uri(path);
});
}
});
You're attempting to copy the picked file into the app package location (InstalledLocation), rather than into an app data folder. The package location is read-only, so CopyAsync should be failing. Use StorageFolder^ localFolder = ApplicationData::Current->LocalFolder; instead.
Also, you do need the /// in ms-appdata:///local because it's a shorthand to omit the package id, but you need only a single / elsewhere in the URI.
Finally, be aware that tile images must be 200KB or smaller and 1024x1024 or smaller, or they won't appear at all. If you're using photographic images, use a JPEG compression; vector images compress best with PNG. For more on dealing with this, see Chapter 16 of my free ebook, Programming Windows Store Apps with HTML, CSS, and JavaScript, 2nd Edition, specifically "Basic Tile Updates" starting on page 887 and the sidebar on page 899. The content is applicable to apps written in all languages, and it's a free book so there's no risk.

Windows Phone 8 choose text file C#

i have a question. If there is a possibility at windows phone 8 at visual studio to create button event to read text file? i know about streamReader and if i declare wchich exacly file i want to read, but if i want to choose from list of files wchich i want to display. i did research on the Internet but i didint find an answer. I know i can use isolatedStorage to read music, video, image but not text files, on the app i created few files with text in it and i want users to have posibility to display one from this file, whichever they want to see. So, can you tell me how to do this?
You can use IsolatedStorage to read any file type you wish. You must of been using something like a Launcher that filters out the file type based on the Chooser.
You can open a file like this:
private async Task<string> ReadTextFile(string file_name)
{
// return buffer
string file_content = "";
// Get the local folder
StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
if (local != null)
{
// Get the file
StorageFile file;
try
{
file = await local.GetFileAsync(file_name);
}
catch (Exception ex)
{
// no file, return empty
return file_content;
}
// Get the stream
System.IO.Stream file_stream = await file.OpenStreamForReadAsync();
// Read the data
using (StreamReader streamReader = new StreamReader(file_stream))
{
file_content = streamReader.ReadToEnd(); // read the full text file
streamReader.Close();
}
// Close the stream
file_stream.Close();
}
// return
return file_content;
}
If you want to get the PackageLocation (files that you added into the project like assets and images) then replace the LocalFolder with
Windows.ApplicationModel.Package package = Windows.ApplicationModel.Package.Current;
Windows.Storage.StorageFolder installedLocation = package.InstalledLocation;
With Windows Phone 8.1, File Pickers are allowed, consisting the same functionality you are expecting, so probably you might want to upgrade your app to WP8.1.
Here's more info on this API : Working with File Pickers

Windows Phone 8 - Saving Microphone File as .wav

I am using following method to save a recording of microphone in WP8 to a file:
private void SaveToIsolatedStorage()
{
// first, we grab the current apps isolated storage handle
IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication();
// we give our file a filename
string strSaveName = "myFile.wav";
// if that file exists...
if (isf.FileExists(strSaveName))
{
// then delete it
isf.DeleteFile(strSaveName);
}
// now we set up an isolated storage stream to point to store our data
IsolatedStorageFileStream isfStream =
new IsolatedStorageFileStream(strSaveName,
FileMode.Create, IsolatedStorageFile.GetUserStoreForApplication());
isfStream.Write(stream.ToArray(), 0, stream.ToArray().Length);
// ok, done with isolated storage... so close it
isfStream.Close();
}
The file is saved. However, I do not know where does it save it, and how can I access it.
I wish to permanently save it to the device so I can access it from outside the app (Let's say from a file explorer app, or from the music player app).
Thanks
Use this code to get saved file name from isolated storage and use this to read this file from stored loacation:
IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication();
String[] filenames=myIsolatedStorage.GetFileNames();

image in local html couldn't be loaded into webview in windows8

I want to load local html file which in the local folder to the webview, but WebView doesn't support 'ms-aspx:///' protocal, I found a solution to read the html file to stream, and then convert it to string, using NavigateToString method to load the html, it works well. But, If there's an image in the html file, the image couldn't display, anyone can help?
I have solved.
Solution:
Convert the image file to base64 string
StorageFolder appFolder = ApplicationData.Current.LocalFolder;
StorageFile file = await appFolder.GetFileAsync("SplashScreen.png");
using (var stream = await file.OpenAsync(FileAccessMode.Read))
{
var reader = new DataReader(stream.GetInputStreamAt(0));
var bytes = new byte[stream.Size];
await reader.LoadAsync((uint)stream.Size);
reader.ReadBytes(bytes);
base64 = Convert.ToBase64String(bytes);
}
Use StringBuilder to create the html string
sb.Append("<html><head><title>Image test</title></head><body><p>This is a test app!</p><img src=\"data:image/png;base64,");
sb.Append(base64);
sb.Append("\" /></body></html>");
TestWebView.NavigateToString(sb.ToString());
Try using the ms-appx-web:// scheme instead of ms-aspx:// to load html from a WebView. If that doesn't work, you may need to use the ms-appdata:// scheme to access the image if it's in your application data folder.
Some further resources that might help:
How to load a local HTML-File into Webview
URI schemes
How to reference content