Develop Reference

Xamarin Failed loading bitmap in skiasharp

I have a problem. I am trying to load an image, so I use this code:
string resourceID = "MyApp.Templates.Good_Question.png";
Assembly assembly = GetType().GetTypeInfo().Assembly;
using (Stream stream = assembly.GetManifestResourceStream(resourceID))
{
bitmap = SKBitmap.Decode(stream);
}
But it gives an error on stream, because stream is null. Now I created a folder in the root of the app called Templates and placed an image called Good_Question.png in the folder.
Why is my stream null?

I found it, I had to set the Build Action to Embedded Resource, not Resource

How to store image uri from gallery in database for loading later in Xamarin.Android?

I want to let a user load an image from their gallery:
var imageIntent = new Intent();
imageIntent.SetType("image/*");
imageIntent.SetAction(Intent.ActionGetContent);
StartActivityForResult(Intent.CreateChooser(imageIntent, "Select photo"), REQUESTCODE);
This works fine: I can use the image in that activity. But I want to store the URI in the database so the image is associated with the object. I use:
_recipeImage.SetImageURI(data.Data);
model.ImageUrl = data.Data.ToString();
_recipeImage is just an image view I'm using to see if I actually got the image correctly for now.
When I save my model to the database I get a string that looks something like:
content://com.android.providers.downloads.documents/document/22
When the user opens this item later the image should load so I parse the string to a Uri. I try and set the image URI as I did before, but no image gets shown.
var uri = Android.Net.Uri.Parse(imageUrl);
imageView.SetImageURI(uri);
Is there a better/working way to do this?

I think you want to load image directly use URL, it's easier to use some third-party lib, for example Picasso.
Since it's a java lib, you can use Binding Library to use it in Xamarin.
After adding this lib into your project, you can simply code like this:
Picasso.With(this).Load(imageUrl).Into(imageView);

Issues loading image from /Assets/ in WPF Application

I'm having some really weird problems trying to load a file pragmatically into my project to save to a local folder.
I can load the file fine in my .xaml code, as so:
<BitmapImage x:Key="Image" UriSource ="/Assets/Submandibular_oedema.jpg" />
And I can display that image on my page. However, when I try to load the image and use it in my xaml.cs code like this
uriMyFile = new Uri("/Assets/Submandibular_oedema.jpg", UriKind.RelativeOrAbsolute);
It cannot find the file and as a result, won't let me do anything with the URI.
For background, my aim is to get the image stream then save it to a local folder.
I know it'll be a stupid little problem, but I can't find any solutions to it.
Thanks!

Try full path (specify your project assembly)
uriMyFile = new Uri("/YourAssemblyName;component/Assets/Submandibular_oedema.jpg",UriKind.RelativeOrAbsolute);

Update after Starktastics comment:
I finally understood your problem: you need the Application.GetResourceStream method to retrieve a stream of your resource, read from that stream and write it to a file stream.
var streamResourceInfo = Application.GetResourceStream(uri);
var stream = streamResourceInfo.Stream;
var byteBuffer = new byte[stream.Length];
using (stream)
{
stream.Read(byteBuffer, 0, byteBuffer.Length);
}
using (var fileStream = new FileStream("photo.jpg", FileMode.Create))
{
fileStream.Write(byteBuffer, 0, byteBuffer.Length);
}
I've updated the solution that you can download here.
Original answer:
If you use a WPF application, make sure that the asset you added to your project is to Build Action 'Resource'. You can check that in the properties pane after you clicked the file.
In any case, your syntax for the URI is correct. I checked it in a small project myself and it works. You can download it here (DropBox link)
Feel free to leave a comment.

Try to use
uriMyFile=new Uri("ms-appx:///Assets/YourImage.png"));
This works for me while trying to show a diffrent map icon for each place.

Windows Phone epub reader

I'm trying to build a wp7 application that must allow user to read ebooks in epub format. Since there isn't any available library to read epub file on a windows phone, I'm trying to create one. So I must unzip the file and then parse it.
The problem is that I can't unzip the epub file. I'm using SharpZipLib.WindowsPhone7.dll but I get an exception:
Attempt to access the method failed: System.IO.File.OpenRead(System.String)
on this line:
ZipInputStream s = new ZipInputStream(File.OpenRead(path_epubfile));
Can any one help me, please?

It's going to depend on how the content is obtained. There's three possible options here;
Option 1: If the content is added to your project with a Build Action of "Content" you can obtain a stream by using the StreamResourceInfo class (In the System.Windows.Resources namespace)
StreamResourceInfo info = Application.GetResourceStream(new Uri("MyContent.txt", UriKind.Relative));
using (info.Stream) {
// Make use of the stream as you will
}
Option 2: If you've added it to your project and set the Build Action to "Embedded Resource" then you'll need to use GetManifestResourceStream()
using (Stream stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("ProjectName.MyContent.txt")) {
// Make use of stream as you will
}
Note: You'll need to replace "ProjectName" with the name of your project. So if your project was "EPubReader" and the embedded resource was "Example.txt" you'd need to pass "EPubReader.Example.txt" to GetManifestResourceStream(). You can use GetManifestResourceNames() to see what resources are available.
Option 3: If you've obtained the content at run time, it'll be stored in IsolatedStorage.
using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication()) {
using (IsolatedStorageFileStream stream = store.OpenFile("MyContent.txt", FileMode.Open)) {
// Make use of stream as you will
}
}

Newb: Update XAML Image Element During Runtime (WIndows Phone, .NET 4)

Greetings all,
Thanks for reading and sharing any insights. I've created a new simple Windows Phone 7 application. I have two Image objects on the form I would like to update with various .png files. I have included the .png files into my project, and I believe I am building proper URi resources pointing to these files.
Uri myImage1URi = new Uri( strImage1, UriKind.RelativeOrAbsolute );
Uri myImage2URi = new Uri( strImage2, UriKind.RelativeOrAbsolute );
System.Windows.Media.Imaging.BitmapImage bi1 = new System.Windows.Media.Imaging.BitmapImage(myImage1URi);
System.Windows.Media.Imaging.BitmapImage bi2 = new System.Windows.Media.Imaging.BitmapImage(myImage2URi);
image1.Source = bi1;
image1.Stretch = Stretch.Fill;
image2.Source = bi2;
image2.Stretch = Stretch.Fill;
This alone is not accomplishing what I want (to update the images to the two from the URi's).
I know there is something a bit off going on (IE: I am doing something dumb) in that all of the BitmapImage class descriptions mention that I have to do a .BeginInit() before I work with the BitmapImage object, and a .EndInit() call afterwards. These method calls don't work for me, so I know something is amiss....
Or maybe I am competely off base and I simply need a way to tell my main window to repaint itself? That thought has occurred to me as well.
Thanks again.

The following will load an image that is in the appropriate path and is set as having a build action content.
myImg.Source = new BitmapImage(new Uri("/images/filename.png", UriKind.Relative));
It assumes XAML on the page like:
<Image x:Name="myImg" />
This seems very similar to what you're doing. Simplify what you're doing ot get it working.
Does it work with just using one image?
Is the path in strImageN a valid path?
Do the image files have their build action set to Content?