public async static void LoadImageFromUrl (ImageView iv, string url, BitmapFactory.Options options = null, int scaleWidth = -1, int scaleHeight = -1, BitmapCompressOptions compressOptions = null)
{
await _loadQueueSemaphore.WaitAsync ();
if (_loadedImageViews.Contains (iv))
_loadedImageViews.Remove (iv);
var l = new CachedImageLoader (url);
var bitmap = await l.LoadInternal (options, scaleWidth, scaleHeight, compressOptions);
_loadQueueSemaphore.Release ();
if (bitmap != null && !_loadedImageViews.Contains (iv)) {
iv.SetImageBitmap (bitmap);
_loadedImageViews.Add (iv);
}
}
public async Task<Bitmap> LoadInternal (BitmapFactory.Options o = null, int scaleWidth = -1,
int scaleHeight = -1, BitmapCompressOptions compressOptions = null)
{
if (String.IsNullOrEmpty (_url)) {
return null;
}
Bitmap bmp = null;
if (compressOptions == null) {
compressOptions = new BitmapCompressOptions ();
}
try {
var uri = new Uri (_url);
var client = new WebClient ();
var stringme = String.Format ("{0}{1}{2}", _url, scaleWidth, scaleHeight);
var urlHash = GetMD5 (new Java.Lang.String (stringme));
var path = Application.Context.CacheDir.AbsolutePath + "/" + urlHash;
var fileInfo = new FileInfo (path);
if (o == null) {
o = new BitmapFactory.Options () { InPurgeable = true };
}
if (_staticRAMCache.ContainsKey (urlHash)) {
return _staticRAMCache [urlHash];
}
if (fileInfo.Exists) {
using (var file = File.Open (path, FileMode.Open, FileAccess.Read)) {
byte[] buff = new byte[file.Length];
await file.ReadAsync (buff, 0, (int)file.Length);
bmp = await BitmapFactory.DecodeByteArrayAsync (buff, 0, buff.Length, o);
_staticRAMCache [urlHash] = bmp;
return bmp;
}
} else {
try {
Log.Debug ("Loading " + uri.ToString ());
var response = await client.DownloadDataTaskAsync (uri);
if (response == null || response.Length <= 0)
return null;
if (scaleWidth > 0 && scaleHeight > 0) {
o.InSampleSize = CalculateInSampleSize (o, scaleWidth, scaleHeight);
}
bmp = await BitmapFactory.DecodeByteArrayAsync (response, 0, response.Length, o);
if (fileInfo.Directory != null) {
fileInfo.Directory.Create ();
}
var fileStream = new FileStream (path,
FileMode.OpenOrCreate,
FileAccess.ReadWrite,
FileShare.ReadWrite);
await bmp.CompressAsync (compressOptions.Format, compressOptions.Quality, fileStream);
fileStream.Close ();
_staticRAMCache [urlHash] = bmp;
return bmp;
} catch (WebException ex) {
Log.Debug (TAG, ex.StackTrace);
return null;
}
}
} catch (System.UriFormatException ex) {
Log.Debug (TAG, ex.StackTrace);
return null;
}
}
