Problems with ShellNamespaceTreeControl

Hello David,

I just wanted to integrate ShellNamespaceTreeControl but found issues:

1. When using the Designer, I get the following MessageBox:

This happens after dropping the Control onto its form in the Designer, and hitting Start the first time.

2. AccessViolationException:

Describe the bug While playing around with the TreeView, trying to expand this and that Node, I sometimes get an AccessViolationException. This isn’t often the case, about 20-30 tries that went okay before the exception occurs.

Don’t think it has to do with a specific folder type, and when, I couldn’t find the pattern this makes it happen.

Here is the debugger’s “View Details” output:

| Name | Value | Type – | – | – | – ◢ | $exception | {“Attempted to read or write protected memory. This is often an indication that other memory is corrupt.”} | System.AccessViolationException   | ▶ Data | {System.Collections.ListDictionaryInternal} | System.Collections.IDictionary {System.Collections.ListDictionaryInternal}   | HResult | 0x80004003 | int   | HelpLink | null | string   | IPForWatsonBuckets | 0x00000000 | System.UIntPtr   | ▶ InnerException | null | System.Exception   | IsTransient | false | bool   | Message | “Attempted to read or write protected memory. This is often an indication that other memory is corrupt.” | string   | RemoteStackTrace | null | string   | Source | “System.Windows.Forms” | string   | StackTrace | " at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)\r\n at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)\r\n at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)\r\n at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)\r\n at System.Windows.Forms.Application.Run(Form mainForm)\r\n at Vanara_ShellNamespaceTreeControl.Program.Main() in S:\[Git.Workspace]\[Test-Projekte]\Vanara-ShellNamespaceTreeControl\Program.cs:line 19" | string   | ▶ TargetSite | {IntPtr DispatchMessageW(MSG ByRef)} | System.Reflection.MethodBase {System.Reflection.RuntimeMethodInfo}   | ▶ WatsonBuckets | {byte[0x000015f0]} | object {byte[]}   | _HResult | 0x80004003 | int   | _accessType | 0x00000000 | int   | _className | null | string   | ▶ _data | {System.Collections.ListDictionaryInternal} | System.Collections.IDictionary {System.Collections.ListDictionaryInternal}   | _dynamicMethods | null | object   | _exceptionMethod | null | System.Reflection.MethodBase   | _exceptionMethodString | null | string   | _helpURL | null | string   | ▶ _innerException | null | System.Exception   | _ip | 0x65ce2f9f | System.IntPtr   | _ipForWatsonBuckets | 0x00000000 | System.UIntPtr   | _message | “Attempted to read or write protected memory. This is often an indication that other memory is corrupt.” | string   | _remoteStackIndex | 0x00000000 | int   | _remoteStackTraceString | null | string   | ▶ _safeSerializationManager | {System.Runtime.Serialization.SafeSerializationManager} | System.Runtime.Serialization.SafeSerializationManager   | _source | “System.Windows.Forms” | string   | ▶ _stackTrace | {sbyte[0x000000c0]} | object {sbyte[]}   | _stackTraceString | null | string   | _target | 0x00000024 | System.IntPtr   | ▶ _watsonBuckets | {byte[0x000015f0]} | object {byte[]}   | _xcode | 0xc0000005 | int   | _xptrs | 0x00bad36c | System.IntPtr   | ◢ Static members |   |     | _COMPlusExceptionCode | 0xe0434352 | int   | s_EDILock | {object} | object

What code is involved

Just a plain Windows Forms window, nothing in it except the ShellNamespaceTreeControl. BTW, this also happened to me using the Unit Test App.

Using Vanara v3.2.12, .net Framework 4.6 on a Windows 10 machine.

Thank you very much in advance, regards,

tajbender

[dahall]

I’ve had to redo much of the ShellNamespaceTreeControl class and am still working through one final bug.

On you second question, there wasn’t a way to get the underlying IShellFolder instance. I just added a property to allow it.

[dahall]

I can’t figure out how, but I just got your exception. I’m opening this up until I can figure it out.