Application.GetContentStream() may fail if the app is in a path that contains a "#".

[neelabo]

• .NET Core Version: .NET 5.0
• Windows version: 21H1
• Does the bug reproduce also in WPF for .NET Framework 4.8?: Yes

Problem description:

Application.GetContentStream() will fail if you place the executable in a path that contains "#".
Apparently, the paths after the "#" have disappeared.

Minimal repro:

For example, if you place the executable file and content file in "C:\FooBar\Path#Name\",
you will get the exception FileNotFoundException: Could not find file 'C:\FooBar\test.png'..

var uri = new Uri("/test.png", UriKind.Relative); // test.png is content file
var streamResourceInfo = Application.GetContentStream(uri); // <- Exception!!

[lindexi]

I wrote a demo in GitHub: https://github.com/lindexi/lindexi_gd/tree/e1022aededd1871017e4c43f228ad1fe26c99b57/ and I found that it seems is the Uri's bug, not the WPF

But I do not think the code in wpf is all right, such as ContentFilePart.cs

wpf/src/Microsoft.DotNet.Wpf/src/PresentationFramework/MS/Internal/AppModel/ContentFilePart.cs

Lines 106 to 130 in 323a02e

	private Uri GetEntryAssemblyLocation()
	{
	Uri entryLocation = null;
	try
	{
	#pragma warning disable // Type or member is obsolete
	entryLocation = new Uri(Application.ResourceAssembly.CodeBase);
	#pragma warning restore // Type or member is obsolete
	}
	catch (Exception ex)
	{
	if (CriticalExceptions.IsCriticalException(ex))
	{
	throw;
	}
	// `Swallow any other exceptions to avoid disclosing the critical path.
	//
	// Possible Exceptions: ArgumentException, ArgumentNullException, PathTooLongException
	// DirectoryNotFoundException, IOException, UnauthorizedAccessException,
	// ArgumentOutOfRangeException, FileNotFoundException, NotSupportedException
	}
	return entryLocation;
	}

The Application.ResourceAssembly.CodeBase will return to the path that contains a # and the URI will be created by this string.