public async Task <string> GetLocalImagePath(Uri webUri)
{
//Download and save image
var localUri = await WebDataCache.GetLocalUriAsync(webUri);
return(localUri.AbsolutePath);
}
private static async void OnCacheUriChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
//Uri oldCacheUri = (Uri)e.OldValue;
Uri newCacheUri = (Uri)d.GetValue(CacheUriProperty);
var image = (Image)d;
if (newCacheUri != null)
{
try
{
//Get image from cache (download and set in cache if needed)
var cacheUri = await WebDataCache.GetLocalUriAsync(newCacheUri);
//Set cache uri as source for the image
image.Source = new BitmapImage(cacheUri);
}
catch (Exception ex)
{
Debug.WriteLine(ex);
//Revert to using passed URI
image.Source = new BitmapImage(newCacheUri);
}
}
else
{
image.Source = null;
}
}
private async static void ActualImageSourceChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
{
DelayLoadImage instance = o as DelayLoadImage;
if (instance == null)
{
return;
}
instance.imageLoaded = false;
var newCacheUri = e.NewValue;
if (newCacheUri == null)
{
return;
}
var cacheUri =
await WebDataCache.GetLocalUriAsync(new Uri(newCacheUri.ToString(), UriKind.RelativeOrAbsolute));
instance._image.UriSource = cacheUri;
VisualStateManager.GoToState(instance, STATE_DEFAULT_NAME, false);
//这里引入Q42的缓存
}
private static async void OnCacheUriChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
//Uri oldCacheUri = (Uri)e.OldValue;
Uri newCacheUri = (Uri)d.GetValue(CacheUriProperty);
if (newCacheUri != null)
{
try
{
//Get image from cache (download and set in cache if needed)
var cacheUri = await WebDataCache.GetLocalUriAsync(newCacheUri);
// Check if the wanted image uri has not changed while we were loading
if (newCacheUri != (Uri)d.GetValue(CacheUriProperty))
{
return;
}
#if NETFX_CORE
//Set cache uri as source for the image
SetSourceOnObject(d, new BitmapImage(cacheUri));
#elif WINDOWS_PHONE
BitmapImage bimg = new BitmapImage();
using (IsolatedStorageFile iso = IsolatedStorageFile.GetUserStoreForApplication())
{
using (IsolatedStorageFileStream stream = iso.OpenFile(cacheUri.PathAndQuery, FileMode.Open, FileAccess.Read))
{
bimg.SetSource(stream);
}
}
//Set cache uri as source for the image
SetSourceOnObject(d, bimg);
#endif
}
catch (Exception ex)
{
Debug.WriteLine(ex);
//Revert to using passed URI
SetSourceOnObject(d, new BitmapImage(newCacheUri), false);
}
}
else
{
SetSourceOnObject(d, null, false);
}
}
public async Task <Uri> GetLocalImageUri(Uri webUri)
{
//First delete all old images
try
{
await WebDataCache.ClearAll();
}
catch (Exception e)
{
}
//Download and save image
var localUri = await WebDataCache.GetLocalUriAsync(webUri);
return(localUri);
}
public object Convert(object value, Type targetType, object parameter, string language)
{
var path = value as string;
if (String.IsNullOrEmpty(path))
{
return(null);
}
var imageFileUri = new Uri(path);
if (imageFileUri.Scheme == "http" || imageFileUri.Scheme == "https")
{
return(WebDataCache.GetLocalUriAsync(imageFileUri).Result);
}
// 不是网络图片,应用内的素材
var bm = new BitmapImage(imageFileUri);
return(bm);
}