/// <summary>
/// Checks to see whether the specified path starts with any of the standard paths supported by <see
/// cref="ExpandPath"/>, and if so, replaces the prefix with a "$(NAME)" string and returns the resulting value.
/// The value passed in should be an absolute path for the substitution to work.</summary>
public static string UnexpandPath(string path)
{
foreach (var folderEnum in EnumStrong.GetValues <Environment.SpecialFolder>())
{
var folderPath = Environment.GetFolderPath(folderEnum);
if (folderPath.Length > 0 && path.StartsWith(folderPath))
{
return("$(" + folderEnum + ")" + path.Substring(folderPath.Length));
}
}
if (path.StartsWith(Path.GetTempPath()))
{
return("$(Temp)" + path.Substring(Path.GetTempPath().Length));
}
return(path);
}
/// <summary>
/// Expands all occurrences of "$(NAME)" in the specified string with the special folder path for the current
/// machine/user. See remarks for details.</summary>
/// <remarks>
/// <para>
/// Expands all occurrences of "$(NAME)", where NAME is the name of one of the values of the <see
/// cref="Environment.SpecialFolder"/> enum. There is no support for escaping such a replacement, and invalid
/// names are ignored.</para>
/// <para>
/// The following additional names are also recognised:</para>
/// <list type="table">
/// <item><term>
/// $(Temp)</term>
/// <description>
/// expands to the system's temporary folder path (Path.GetTempPath()).</description></item>
/// <item><term>
/// $(AppPath)</term>
/// <description>
/// expands to the directory containing the entry assembly (Assembly.GetEntryAssembly()). Throws an <see
/// cref="InvalidOperationException"/> if there is no entry assembly (e.g. in a secondary app domain).</description></item></list></remarks>
public static string ExpandPath(string path)
{
foreach (var folderEnum in EnumStrong.GetValues <Environment.SpecialFolder>())
{
path = path.Replace("$(" + folderEnum + ")", Environment.GetFolderPath(folderEnum));
}
path = path.Replace("$(Temp)", Path.GetTempPath());
if (path.Contains("$(AppPath)"))
{
if (Assembly.GetEntryAssembly() == null)
{
throw new InvalidOperationException("ExpandPath() cannot expand $(AppPath) in an AppDomain where Assembly.GetEntryAssembly() is null.");
}
path = path.Replace("$(AppPath)", Path.GetDirectoryName(Assembly.GetEntryAssembly().Location));
}
return(path);
}
