public virtual async Task <bool> GenerateAsync(string imageUrl, bool isRegenerateAll)
{
if (string.IsNullOrEmpty(imageUrl))
{
throw new ArgumentNullException("imageUrl");
}
var thumbnailsParameters = GetThumbnailParameters();
if (thumbnailsParameters.IsNullOrEmpty())
{
return(false);
}
var originalImage = await LoadImageAsync(imageUrl);
var format = GetImageFormat(originalImage);
foreach (var parameters in thumbnailsParameters)
{
var thumbnailUrl = AddAliasToImageUrl(imageUrl, parameters.Alias);
if (isRegenerateAll || !Exists(thumbnailUrl))
{
//one process only can use an Image object at the same time.
Image clone;
lock (_progressLock)
{
clone = (Image)originalImage.Clone();
}
//Generate a Thumbnail
Image thumbnail = null;
switch (parameters.Method)
{
case ResizeMethod.FixedSize:
thumbnail = ImageResizer.FixedSize(clone, parameters.Width, parameters.Height, parameters.Color);
break;
case ResizeMethod.FixedWidth:
thumbnail = ImageResizer.FixedWidth(clone, parameters.Width, parameters.Color);
break;
case ResizeMethod.FixedHeight:
thumbnail = ImageResizer.FixedHeight(clone, parameters.Height, parameters.Color);
break;
case ResizeMethod.Crop:
thumbnail = ImageResizer.Crop(clone, parameters.Width, parameters.Height, parameters.AnchorPosition);
break;
}
//Save
if (thumbnail != null)
{
SaveImage(thumbnailUrl, thumbnail, format);
}
else
{
throw new ThumbnailGenetationException(string.Format(CultureInfo.InvariantCulture, "Cannot generate thumbnail for image '{0}'.", thumbnailUrl));
}
}
}
return(true);
}