Open a new file in memory from extension using custom editor

To open a new in-memory file using your custom editor factory in Visual Studio, you need to ensure that you are correctly implementing the OpenStandardEditor method and handling the parameters appropriately. The error you are encountering, "Attempted to read or write protected memory," often indicates an issue with how the parameters are passed or how the editor is set up.

Here's a sample code snippet that demonstrates how to open a new in-memory file with a custom editor:

IVsUIShellOpenDocument shellOpenDocument = Microsoft.VisualStudio.Shell.Package.GetGlobalService(typeof(SVsUIShellOpenDocument)) as IVsUIShellOpenDocument;
Guid editorFactoryGuid = new Guid(<editor factory guid>);
Guid logicalViewGuid = VSConstants.LOGVIEWID_Primary;
IVsUIHierarchy parentHierarchy = null;
uint itemId = (uint)VSConstants.VSITEMID.Nil;
IVsWindowFrame windowFrame = null;
__VSOSEFLAGS openFlags = __VSOSEFLAGS.OSE_OpenAsNewFile;
string ownerCaption = null;
string mkDocument = "Untitled1.sql";
IServiceProvider serviceProvider = (IServiceProvider)package;
IntPtr punkDocDataExisting = IntPtr.Zero;

// Ensure to create a new document data object if necessary
IntPtr punkDocDataNew = IntPtr.Zero;
int hr = shellOpenDocument.OpenStandardEditor(
    (uint)openFlags,          
    mkDocument,               
    ref logicalViewGuid,      
    ownerCaption,             
    parentHierarchy,          
    itemId,                   
    punkDocDataNew,          // Use new document data pointer
    serviceProvider,          
    out windowFrame           
);

if (ErrorHandler.Succeeded(hr)) {
    // Successfully opened the document
} else {
    // Handle the error
}

Key Points:

1. Document Data Pointer: Ensure that you are using a valid document data pointer. If you are trying to open a new document, you might need to create a new document data object instead of using punkDocDataExisting.
2. Error Handling: Always check the HRESULT returned by the OpenStandardEditor method to handle any errors appropriately.
3. Custom Editor Registration: Make sure your custom editor is properly registered in the Visual Studio environment and associated with the .sql file extension.

If the issue persists, consider reviewing the implementation of your custom editor factory to ensure it is set up correctly to handle in-memory documents.

References:

• Determine which editor opens a file in a project
• Walkthrough: Create a custom editor

This issue is not resolved. Call to OpenStandardEditor with the suggested parameters throws an exception and IVsEditorFactory.CreateEditorInstance is not getting called.

 
Regarding the command mentioned above: To open an in-memory "Untitled1.sql" file with your custom editor factory, do not call OpenStandardEditor directly (if often causes Access Violation)

Reference: Running Document Table - Visual Studio (Windows) | Microsoft Learn

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