/// <summary>
/// Extract the icon from file.
/// </summary>
/// <param name="fileAndParam">The params string,
/// such as ex: "C:\\Program Files\\NetMeeting\\conf.exe,1".</param>
/// <returns>This method always returns the large size of the icon (may be 32x32 px).</returns>
public static Icon ExtractIconFromFile(string fileAndParam)
{
try
{
EmbeddedIconInfo embeddedIcon = getEmbeddedIconInfo(fileAndParam);
//Gets the handle of the icon.
IntPtr lIcon = ExtractIcon(0, embeddedIcon.FileName, embeddedIcon.IconIndex);
//Gets the real icon.
return(Icon.FromHandle(lIcon));
}
catch (Exception exc)
{
throw exc;
}
}
/// <summary>
/// Parses the parameters string to the structure of EmbeddedIconInfo.
/// </summary>
/// <param name="fileAndParam">The params string,
/// such as ex: "C:\\Program Files\\NetMeeting\\conf.exe,1".</param>
/// <returns></returns>
protected static EmbeddedIconInfo getEmbeddedIconInfo(string fileAndParam)
{
EmbeddedIconInfo embeddedIcon = new EmbeddedIconInfo();
if (String.IsNullOrEmpty(fileAndParam))
{
return(embeddedIcon);
}
//Use to store the file contains icon.
string fileName = String.Empty;
//The index of the icon in the file.
int iconIndex = 0;
string iconIndexString = String.Empty;
int commaIndex = fileAndParam.IndexOf(",");
//if fileAndParam is some thing likes that: "C:\\Program Files\\NetMeeting\\conf.exe,1".
if (commaIndex > 0)
{
fileName = fileAndParam.Substring(0, commaIndex);
iconIndexString = fileAndParam.Substring(commaIndex + 1);
}
else
{
fileName = fileAndParam;
}
if (!String.IsNullOrEmpty(iconIndexString))
{
//Get the index of icon.
iconIndex = int.Parse(iconIndexString);
if (iconIndex < 0)
{
iconIndex = 0; //To avoid the invalid index.
}
}
embeddedIcon.FileName = fileName;
embeddedIcon.IconIndex = iconIndex;
return(embeddedIcon);
}
/// <summary>
/// Parses the parameters string to the structure of EmbeddedIconInfo.
/// </summary>
/// <param name="fileAndParam">The params string,
/// such as ex: "C:\\Program Files\\NetMeeting\\conf.exe,1".</param>
/// <returns></returns>
protected static EmbeddedIconInfo getEmbeddedIconInfo(string fileAndParam)
{
EmbeddedIconInfo embeddedIcon = new EmbeddedIconInfo();
if (string.IsNullOrEmpty(fileAndParam))
return embeddedIcon;
//Use to store the file contains icon.
string fileName = string.Empty;
//The index of the icon in the file.
int iconIndex = 0;
string iconIndexString = string.Empty;
int commaIndex = fileAndParam.IndexOf(",");
//if fileAndParam is some thing likes that: "C:\\Program Files\\NetMeeting\\conf.exe,1".
if (commaIndex > 0)
{
fileName = fileAndParam.Substring(0, commaIndex);
iconIndexString = fileAndParam.Substring(commaIndex + 1);
}
else
fileName = fileAndParam;
if (!string.IsNullOrEmpty(iconIndexString))
{
//Get the index of icon.
iconIndex = int.Parse(iconIndexString);
if (iconIndex < 0)
iconIndex = 0; //To avoid the invalid index.
}
embeddedIcon.FileName = fileName;
embeddedIcon.IconIndex = iconIndex;
return embeddedIcon;
}
/// <summary>
/// Extract the icon from file.
/// </summary>
/// <param name="fileAndParam">The params string,
/// such as ex: "C:\\Program Files\\NetMeeting\\conf.exe,1".</param>
/// <param name="isLarge">
/// Determines the returned icon is a large (may be 32x32 px)
/// or small icon (16x16 px).</param>
public static Icon ExtractIconFromFile(string fileAndParam, bool isLarge)
{
unsafe
{
uint readIconCount = 0;
IntPtr[] hDummy = new IntPtr[1] {
IntPtr.Zero
};
IntPtr[] hIconEx = new IntPtr[1] {
IntPtr.Zero
};
try
{
EmbeddedIconInfo embeddedIcon = getEmbeddedIconInfo(fileAndParam);
if (isLarge)
{
readIconCount = ExtractIconEx(embeddedIcon.FileName, 0, hIconEx, hDummy, 1);
}
else
{
readIconCount = ExtractIconEx(embeddedIcon.FileName, 0, hDummy, hIconEx, 1);
}
if (readIconCount > 0 && hIconEx[0] != IntPtr.Zero)
{
// Get first icon.
Icon extractedIcon = (Icon)Icon.FromHandle(hIconEx[0]).Clone();
return(extractedIcon);
}
else // No icon read
{
return(null);
}
}
catch (Exception exc)
{
// Extract icon error.
throw new ApplicationException("Could not extract icon", exc);
}
finally
{
// Release resources.
foreach (IntPtr ptr in hIconEx)
{
if (ptr != IntPtr.Zero)
{
DestroyIcon(ptr);
}
}
foreach (IntPtr ptr in hDummy)
{
if (ptr != IntPtr.Zero)
{
DestroyIcon(ptr);
}
}
}
}
}
