Microsoft.VisualStudio.Project.ImageHandler.GetIconHandle C# (CSharp) Method

        public virtual IntPtr GetIconHandle(int iconIndex)
        {
            // Verify that the object is in a consistent state.
            if((null == imageList))
            {
                throw new InvalidOperationException();
            }
            // Make sure that the list of handles is initialized.
            if(null == iconHandles)
            {
                InitHandlesList();
            }

            // Verify that the index is inside the expected range.
            if((iconIndex < 0) || (iconIndex >= iconHandles.Count))
            {
                throw new ArgumentOutOfRangeException("iconIndex");
            }

            // Check if the icon is in the cache.
            if(IntPtr.Zero == iconHandles[iconIndex])
            {
                Bitmap bitmap = imageList.Images[iconIndex] as Bitmap;
                // If the image is not a bitmap, then we can not build the icon,
                // so we have to return a null handle.
                if(null == bitmap)
                {
                    return IntPtr.Zero;
                }

                iconHandles[iconIndex] = bitmap.GetHicon();
            }

            return iconHandles[iconIndex];
        }

        public override object GetIconHandle(bool open)
        {
            Debug.Assert(this.nestedHierarchy != null, "The nested hierarchy object must be created before calling this method");
            ThreadHelper.ThrowIfNotOnUIThread();

            object iconHandle = null;

            this.nestedHierarchy.GetProperty(VSConstants.VSITEMID_ROOT, (int)__VSHPROPID.VSHPROPID_IconHandle, out iconHandle);
            if (iconHandle == null)
            {
                if (null == imageHandler)
                {
                    InitImageHandler();
                }
                // Try to get an icon from the nested hierrachy image list.
                if (imageHandler.ImageList != null)
                {
                    object imageIndexAsObject = null;
                    if (this.nestedHierarchy.GetProperty(VSConstants.VSITEMID_ROOT, (int)__VSHPROPID.VSHPROPID_IconIndex, out imageIndexAsObject) == VSConstants.S_OK &&
                        imageIndexAsObject != null)
                    {
                        int imageIndex = (int)imageIndexAsObject;
                        if (imageIndex < imageHandler.ImageList.Images.Count)
                        {
                            iconHandle = imageHandler.GetIconHandle(imageIndex);
                        }
                    }
                }

                if (null == iconHandle)
                {
                    iconHandle = this.ProjectMgr.ImageHandler.GetIconHandle((int)ProjectNode.ImageName.Application);
                }
            }

            return(iconHandle);
        }