How to show modeless owned dialog in .NET 1.1

Question

I need to show a modeless dialog in .NET 1.1 . The following code works in .NET 2.0 or higher:

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
private static extern IntPtr GetActiveWindow();

private void ShowModelessOwnedDialog()
{
   IntPtr wHnd = GetActiveWindow();
   NativeWindow parent = NativeWindow.FromHandle(wHnd);
   MyForm f = new MyForm();
   f.Show(parent);
}

The call Show(IWin32Window) was introduced in .NET 2.0. Do you know how to trick this code to work in .NET 1.1 ? Maybe any unmanaged call?

Answer 1

Here is an article from way back in 1999, showing how you call SetWindowLong to accomplish this. My condolences to you for having to use .NET version 1.

Answer 2

This is the way to assign an owner to a managed form in .NET 1.1. I extracted the following code from @Dave Markle answer and the Show(IWin32Window) implemantation of .NET 2.0.

    private void AssignOwner()
    {
        AssignOwner(this, GetActiveWindow());
    }

    private void AssignOwner(Form f, IntPtr ownerHandle)
    {
        if (ownerHandle == IntPtr.Zero) return;

        NativeWindow parent = NativeWindow.FromHandle(ownerHandle);

        GetWindowLong(new HandleRef(f, f.Handle), -8);
        SetWindowLong(new HandleRef(f, f.Handle), -8, new HandleRef(parent, ownerHandle));
    }

    public static IntPtr GetWindowLong(HandleRef hWnd, int nIndex)
    {
        if (IntPtr.Size == 4)
        {
            return GetWindowLong32(hWnd, nIndex);
        }
        return GetWindowLongPtr64(hWnd, nIndex);
    }

    public static IntPtr SetWindowLong(HandleRef hWnd, int nIndex, HandleRef dwNewLong)
    {
        if (IntPtr.Size == 4)
        {
            return SetWindowLongPtr32(hWnd, nIndex, dwNewLong);
        }
        return SetWindowLongPtr64(hWnd, nIndex, dwNewLong);
    }

    [DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
    private static extern IntPtr GetActiveWindow();
    [DllImport("user32.dll", EntryPoint = "GetWindowLong", CharSet = CharSet.Auto)]
    public static extern IntPtr GetWindowLong32(HandleRef hWnd, int nIndex);
    [DllImport("user32.dll", EntryPoint = "GetWindowLongPtr", CharSet = CharSet.Auto)]
    public static extern IntPtr GetWindowLongPtr64(HandleRef hWnd, int nIndex);
    [DllImport("user32.dll", EntryPoint = "SetWindowLong", CharSet = CharSet.Auto)]
    public static extern IntPtr SetWindowLongPtr32(HandleRef hWnd, int nIndex, HandleRef dwNewLong);
    [DllImport("user32.dll", EntryPoint = "SetWindowLongPtr", CharSet = CharSet.Auto)]
    public static extern IntPtr SetWindowLongPtr64(HandleRef hWnd, int nIndex, HandleRef dwNewLong);

Answer 3

MSDN states that after creating the window ownership cannot be transferred.
Because creating the window occurs in Form constructor, this poses a problem for you.

However Raymond Chen says :

Ownership is a concept that relates top-level windows. A top-level window can optionally have an owner, which is also specified when you call CreateWindowEx , and which you can change by a complicated mechanism described in my talk .

I assume the talk in question is from PDC 05 but I can't be certain.

Did you give SetParent a try?

static extern void SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

Answer 4

There is a MessageBox.Show overload taking and IWin32Window in .net 1.1

http://msdn.microsoft.com/en-us/library/aa335416(v=VS.71).aspx

public static DialogResult Show(
 IWin32Window owner,
 string text,
 string caption,
 MessageBoxButtons buttons,
 MessageBoxIcon icon,
 MessageBoxDefaultButton defaultButton
);

And this and example of getting an IWin2Window here