/// <summary>
/// Handles the DoWork event of the queued background worker.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="PanoClient.ImageListView.QueuedWorkerDoWorkEventArgs"/> instance
/// containing the event data.</param>
void bw_DoWork(object sender, QueuedWorkerDoWorkEventArgs e)
{
string extension = e.Argument as string;
// Should we continue processing this item?
// The callback checks if the item is already cached.
if (!OnCanContinueProcessing(extension))
{
e.Cancel = true;
return;
}
// Read shell info
ShellInfoExtractor info = ShellInfoExtractor.FromFile(extension);
// Return the info
CacheItem result = null;
if ((info.SmallIcon == null || info.LargeIcon == null) && !RetryOnError)
{
result = new CacheItem(extension, info.SmallIcon, info.LargeIcon, info.FileType, CacheState.Error);
}
else
{
result = new CacheItem(extension, info.SmallIcon, info.LargeIcon, info.FileType, CacheState.Cached);
}
e.Result = result;
}
/// <summary>
/// Creates an instance of the ShellInfoExtractor class.
/// </summary>
/// <param name="path">Filepath of image</param>
public static ShellInfoExtractor FromFile(string path)
{
ShellInfoExtractor info = new ShellInfoExtractor();
try
{
SHFILEINFO shinfo = new SHFILEINFO();
uint structSize = (uint)Marshal.SizeOf(shinfo);
SHGFI flags = SHGFI.Icon | SHGFI.SmallIcon | SHGFI.TypeName | SHGFI.UseFileAttributes;
// Get the small icon and shell file type
IntPtr hImg = SHGetFileInfo(path, FileAttributes.Normal, out shinfo,
structSize, flags);
// Get mime type
info.FileType = shinfo.szTypeName;
// Get small icon
if (hImg != IntPtr.Zero && shinfo.hIcon != IntPtr.Zero)
{
using (Icon newIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon))
{
info.SmallIcon = newIcon.ToBitmap();
}
DestroyIcon(shinfo.hIcon);
}
else
{
info.Error = new Exception("Error reading shell icon");
}
// Get large icon
hImg = SHGetFileInfo(path, FileAttributes.Normal, out shinfo,
structSize, SHGFI.Icon | SHGFI.LargeIcon | SHGFI.UseFileAttributes);
if (hImg != IntPtr.Zero && shinfo.hIcon != IntPtr.Zero)
{
using (Icon newIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon))
{
info.LargeIcon = newIcon.ToBitmap();
}
DestroyIcon(shinfo.hIcon);
}
else
{
info.Error = new Exception("Error reading shell icon");
}
}
catch (Exception e)
{
info.Error = e;
}
return(info);
}
