How to: Extract the Icon Associated with a File in Windows Forms

Many files have embedded icons that provide a visual representation of the associated file type. For example, Microsoft Word documents contain an icon that identifies them as Word documents. When displaying files in a list control or table control, you may want to display the icon representing the file type next to each file name. You can do this easily by using the ExtractAssociatedIcon method.


The following code example demonstrates how to extract the icon associated with a file and display the file name and its associated icon in a ListView control.

ListView listView1;
ImageList imageList1;

public void ExtractAssociatedIconEx()
    // Initialize the ListView, ImageList and Form.
    listView1 = new ListView();
    imageList1 = new ImageList();
    listView1.Location = new Point(37, 12);
    listView1.Size = new Size(151, 262);
    listView1.SmallImageList = imageList1;
    listView1.View = View.SmallIcon;
    this.ClientSize = new System.Drawing.Size(292, 266);
    this.Text = "Form1";

    // Get the c:\ directory.
    System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(@"c:\");
    ListViewItem item;

    // For each file in the c:\ directory, create a ListViewItem
    // and set the icon to the icon extracted from the file.
    foreach (FileInfo file in dir.GetFiles())
        // Set a default icon for the file.
        Icon iconForFile = SystemIcons.WinLogo;

        item = new ListViewItem(file.Name, 1);
        iconForFile = Icon.ExtractAssociatedIcon(file.FullName);
        // Check to see if the image collection contains an image
        // for this extension, using the extension as a key.
        if (!imageList1.Images.ContainsKey(file.Extension))
            // If not, add the image to the image list.
            iconForFile = System.Drawing.Icon.ExtractAssociatedIcon(file.FullName);
            imageList1.Images.Add(file.Extension, iconForFile);
        item.ImageKey = file.Extension;

Compiling the Code

To compile the example:

  • Paste the preceding code into a Windows Form, and call the ExtractAssociatedIconExample method from the form's constructor or Load event-handling method.

    You will need to make sure that your form imports the System.IO namespace.

See Also

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