Speed up retrieve image into picturebox

Question

I'm currently working on windows form application which allow user to retrieve image after searching at textbox. The problem is the image is load very slow. How can I overcome this problem to speed up the loading? If anyone has suggestions for a faster way to retrieve these images, it would be greatly appreciated. Here is my code:

  string baseFolder = @"\\\\jun01\\hr\\photo";
  string imgName =  "*" + textBoxEmplNo.Text  + "*.jpg";

  //Bool to see if file is found after checking all
  bool fileFound = false;

  DirectoryInfo di = new DirectoryInfo(baseFolder);
  foreach (var file in di.GetFiles(imgName, SearchOption.AllDirectories))

   {
    pictureBox1.Visible = true;
    pictureBox1.Image = Image.FromFile(file.FullName);

    fileFound = true;
    break;
   }

    if (!fileFound)
   {
    pictureBox1.Visible = true;
    pictureBox1.Image = Image.FromFile(@"\\\\jun01\\hr\\photo\\No-image-
    found.jpg");
   }

Answer 1

It's very likely here that the slowness you are experiencing is due to the wildcard search on all files in a remote directory, and/or potentially transferring a large file over the network for display in the PictureBox. You should time these two operations using a profiler (see for example https://www.simple-talk.com/dotnet/net-performance/the-why-and-how-of-net-profiling/) and consider optimizing the operations that take the most time.

Some possibilities might include pre-downloading all the images before the user makes a selection or downloading on a background thread while displaying a "Please wait" message on the UI.

Answer 2

It could be the case that the code slowness is due to the wildcard search on all files: (e.g. di.GetFiles takes too long)

• Too many files in your top folder/subfolders.

• The network connection is too slow to fetch file information or photos are too big. (remote directory access could be slow - you can check by copying a big file say 1GB to your remote directory and copy back to your PC)

• The photos may be stored with different aspect ratios to your picture box size. (Rendering takes a while if resizing needs to happen)

For starters, let us assume your folder has too many files (1000s), then we need to do a smarter search for the first file folder by folder:

string baseFolder = @"\\\\jun01\\hr\\photo";
string imgName =  "*" + textBoxEmplNo.Text  + "*.jpg";

var file = FindFirstFile(baseFolder, imgName);
if (!string.IsNullorEmpty(file))
{
  pictureBox1.Visible = true;
  pictureBox1.Image = Image.FromFile(file);
}
else
{
 pictureBox1.Visible = true;
 pictureBox1.Image = Image.FromFile(@"\\\\jun01\\hr\\photo\\No-image-found.jpg");
}

where FindFirstFile is taken from Markus's answer as:

public static string FindFirstFile(string path, string searchPattern)
{
    string[] files;

    try
    {
        // Exception could occur due to insufficient permission.
        files = Directory.GetFiles(path, searchPattern, SearchOption.TopDirectoryOnly);
    }
    catch (Exception)
    {
        return string.Empty;
    }

    if (files.Length > 0)
    {
        return files[0];
    }
    else
    {
        // Otherwise find all directories.
        string[] directories;

        try
        {
            // Exception could occur due to insufficient permission.
            directories = Directory.GetDirectories(path);
        }
        catch (Exception)
        {
            return string.Empty;
        }

        // Iterate through each directory and call the method recursivly.
        foreach (string directory in directories)
        {
            string file = FindFirstFile(directory, searchPattern);

            // If we found a file, return it (and break the recursion).
            if (file != string.Empty)
            {
                return file;
            }
        }
    }

    return string.Empty;
}