- 1 year ago
Default column index for sorting in Shell Namespace Extension
In a Shell Namespace Extension, the default column index for sorting is typically determined by the shell based on the column that is currently selected by the user in the explorer window.
When a user selects a column for sorting in Windows Explorer, the shell communicates the selected column's index to the Shell Namespace Extension. The extension can then use this information to sort the items accordingly.
To retrieve the selected column index in a Shell Namespace Extension, you can use the IShellFolderView
interface. Here's an example of how you can obtain the selected column index:
csharpusing System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace ShellNamespaceExtension
{
[ComVisible(true)]
[Guid("YOUR_GUID_HERE")]
public class MyNamespaceExtension : IShellFolder, IShellDetails
{
// Other implementation code...
public int CompareDetailsEx(IntPtr lParam, int iColumn, ShellDetailsCompareFlags flags)
{
// Get the selected column index
int selectedColumnIndex = GetSelectedColumnIndex();
// Perform the sorting based on the selected column index and iColumn
// Return the comparison result
// ...
}
private int GetSelectedColumnIndex()
{
// Get the Shell folder view interface
var shellFolderView = GetShellFolderView();
if (shellFolderView == null)
{
// Handle the case when ShellFolderView is not available
return -1;
}
// Get the selected column index
int selectedIndex;
if (shellFolderView.GetSortColumnIndex(out selectedIndex) == 0)
{
return selectedIndex;
}
// Handle the case when the selected column index retrieval fails
return -1;
}
private IShellFolderView GetShellFolderView()
{
// Retrieve the active Shell folder view
IntPtr shellFolderViewPtr;
if (NativeMethods.SHGetActiveShellView(out shellFolderViewPtr) == 0)
{
return (IShellFolderView)Marshal.GetObjectForIUnknown(shellFolderViewPtr);
}
// Handle the case when retrieving the active Shell folder view fails
return null;
}
}
// Native methods for interop
internal static class NativeMethods
{
[DllImport("shell32.dll")]
public static extern int SHGetActiveShellView(out IntPtr ppshv);
}
}
In this example, the CompareDetailsEx
method is responsible for comparing the details of items in the Shell Namespace Extension. Inside this method, the GetSelectedColumnIndex
function retrieves the selected column index by calling the GetSortColumnIndex
method of the IShellFolderView
interface obtained through GetShellFolderView
.
Please note that this is just a basic example, and you may need to adapt it to your specific implementation and requirements.