private async Task GetItemsAsync()
{
// https://docs.microsoft.com/uwp/api/windows.ui.xaml.controls.image#Windows_UI_Xaml_Controls_Image_Source
// See "Using a stream source to show images from the Pictures library".
// This code is modified to get images from the app folder.
// Get the app folder where the images are stored.
StorageFolder appInstalledFolder = Package.Current.InstalledLocation;
StorageFolder assets = await appInstalledFolder.GetFolderAsync("Assets\\Samples");
// Get and process files in folder
IReadOnlyList <StorageFile> fileList = await assets.GetFilesAsync();
foreach (StorageFile file in fileList)
{
// Limit to only png or jpg files.
if (file.ContentType == "image/png" || file.ContentType == "image/jpeg")
{
ImageFileInfo image = await LoadImageInfo(file);
if (!Images.Contains(image))
{
Images.Add(image);
}
}
}
// Populate the new ImageGridView with the loaded images
// Replaced with XAMl binding:
// ImageGridView.ItemsSource = Images;
}
private async Task LoadSavedImageAsync(StorageFile imageFile, bool replaceImage)
{
item.NeedsSaved = false;
var newItem = await MainPage.LoadImageInfo(imageFile);
ResetEffects();
// Get the index of the original image so we can
// insert the saved image in the same place.
var index = MainPage.Current.Images.IndexOf(item);
item = newItem;
this.Bindings.Update();
UnloadObject(imgRect);
FindName("imgRect");
await LoadBrushAsync();
// Insert the saved image into the collection.
if (replaceImage == true)
{
MainPage.Current.Images.RemoveAt(index);
MainPage.Current.Images.Insert(index, item);
}
else
{
MainPage.Current.Images.Insert(index + 1, item);
}
// Replace the persisted image used for connected animation.
MainPage.Current.UpdatePersistedItem(item);
}
private void ImageGridView_ItemClick(object sender, ItemClickEventArgs e)
{
// Prepare the connected animation for navigation to the detail page.
persistedItem = e.ClickedItem as ImageFileInfo;
ImageGridView.PrepareConnectedAnimation("itemAnimation", e.ClickedItem, "ItemImage");
this.Frame.Navigate(typeof(DetailPage), e.ClickedItem);
}
public async static Task <ImageFileInfo> LoadImageInfo(StorageFile file)
{
var properties = await file.Properties.GetImagePropertiesAsync();
ImageFileInfo info = new ImageFileInfo(
properties, file,
file.DisplayName, file.DisplayType);
return(info);
}
protected override async void OnNavigatedTo(NavigationEventArgs e)
{
item = e.Parameter as ImageFileInfo;
canNavigateWithUnsavedChanges = false;
ImageSource = await item.GetImageSourceAsync();
if (item != null)
{
ConnectedAnimation imageAnimation = ConnectedAnimationService.GetForCurrentView().GetAnimation("itemAnimation");
if (imageAnimation != null)
{
targetImage.Source = ImageSource;
imageAnimation.Completed += async(s, e_) =>
{
await LoadBrushAsync();
// This delay prevents a flicker that can happen when
// a large image is being loaded to the brush. It gives
// the image time to finish loading. (200 is ok, 400 to be safe.)
await Task.Delay(400);
targetImage.Source = null;
};
imageAnimation.TryStart(targetImage);
}
if (ImageSource.PixelHeight == 0 && ImageSource.PixelWidth == 0)
{
// There is no editable image loaded. Disable zoom and edit
// to prevent other errors.
EditButton.IsEnabled = false;
ZoomButton.IsEnabled = false;
}
;
}
else
{
// error
}
if (this.Frame.CanGoBack)
{
SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible;
}
else
{
SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = AppViewBackButtonVisibility.Collapsed;
}
base.OnNavigatedTo(e);
}
public async static Task <ImageFileInfo> LoadImageInfo(StorageFile file)
{
// Open a stream for the selected file.
// The 'using' block ensures the stream is disposed
// after the image is loaded.
using (IRandomAccessStream fileStream = await file.OpenReadAsync())
{
// Create a bitmap to be the image source.
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.SetSource(fileStream);
var properties = await file.Properties.GetImagePropertiesAsync();
ImageFileInfo info = new ImageFileInfo(
properties, file, bitmapImage,
file.DisplayName, file.DisplayType);
return(info);
}
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
item = e.Parameter as ImageFileInfo;
canNavigateWithUnsavedChanges = false;
ResetEffects();
if (item != null)
{
item.PropertyChanged += (s, e2) => UpdateEffectBrush(e2.PropertyName);
targetImage.Source = item.ImageSource;
ConnectedAnimation imageAnimation = ConnectedAnimationService.GetForCurrentView().GetAnimation("itemAnimation");
if (imageAnimation != null)
{
imageAnimation.Completed += (s, e_) =>
{
MainImage.Source = item.ImageSource;
targetImage.Source = null;
};
imageAnimation.TryStart(targetImage);
}
}
else
{
// error
}
if (this.Frame.CanGoBack)
{
SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible;
}
else
{
SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = AppViewBackButtonVisibility.Collapsed;
}
base.OnNavigatedTo(e);
}
// If the image is edited and saved in the details page, this method gets called
// so that the back navigation connected animation uses the correct image.
public void UpdatePersistedItem(ImageFileInfo item)
{
persistedItem = item;
}
private async void ExportImage()
{
CanvasDevice device = CanvasDevice.GetSharedDevice();
using (CanvasRenderTarget offscreen = new CanvasRenderTarget(
device, item.ImageSource.PixelWidth, item.ImageSource.PixelHeight, 96))
{
using (IRandomAccessStream stream = await item.ImageFile.OpenReadAsync())
using (CanvasBitmap image = await CanvasBitmap.LoadAsync(offscreen, stream, 96))
{
saturationEffect.Source = image;
using (CanvasDrawingSession ds = offscreen.CreateDrawingSession())
{
ds.Clear(Windows.UI.Colors.Black);
// Need to copy the value of each effect setting.
contrastEffect.Contrast = item.Contrast;
exposureEffect.Exposure = item.Exposure;
temperatureAndTintEffect.Temperature = item.Temperature;
temperatureAndTintEffect.Tint = item.Tint;
saturationEffect.Saturation = item.Saturation;
graphicsEffect.BlurAmount = item.Blur;
ds.DrawImage(graphicsEffect);
}
var fileSavePicker = new FileSavePicker()
{
SuggestedSaveFile = item.ImageFile
};
fileSavePicker.FileTypeChoices.Add("JPEG files", new List <string>()
{
".jpg"
});
var outputFile = await fileSavePicker.PickSaveFileAsync();
if (outputFile != null)
{
using (IRandomAccessStream outStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
await offscreen.SaveAsync(outStream, CanvasBitmapFileFormat.Jpeg);
}
ResetEffects();
var newItem = await MainPage.LoadImageInfo(outputFile);
if (outputFile.Path == item.ImageFile.Path)
{
item.ImageSource = newItem.ImageSource;
}
else
{
item = newItem;
}
MainImage.Source = item.ImageSource;
}
}
}
}