C# 在NativeWindow中处理WM_GETOBJECT返回IOleCommandTarget

我试图从面板控件句柄检索IOleCommandTarget引用，以便对其调用IOleCommandTarget.Exec（）

为了能够返回IOleCommandTarget引用，我创建了一个CommandTargetWindow类，该类实现了NativeWindow和IOleCommandTarget，我正在重写WndProc以截获AccessibleObjectFromWindow（）发送的WM_GETOBJECT消息：

问题是，正如上面的评论一样，我如何通过消息传回IOleCommandTarget？

为了实现自动化，我们在其他地方也做了类似的事情，实现了接口irawlementprovidersimple（而不是IOleCommandTarget），并使用定义的静态方法AutomationInteropProvider.ReturnRawElementProvider（）：

---

有什么想法吗？

事实证明我需要使用COM方法LresultFromObject，我在NativeMethods.cs中定义为

[DllImport("oleacc.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern IntPtr LresultFromObject(ref Guid refiid, IntPtr wParam, IntPtr pAcc);

现在在我的WndProc中，我调用LresultFromObject以返回m中的IOleCommandTarget句柄。结果：

[PermissionSetAttribute(SecurityAction.Demand, Unrestricted = true)]
protected override void WndProc(ref System.Windows.Forms.Message m)
{
    if (m.Msg == (int)NativeMethods.WindowMessage.GETOBJECT)
    {
        if (m.LParam.ToInt32() == AutomationInteropProvider.RootObjectId)
        {
            m.Result = AutomationInteropProvider.ReturnRawElementProvider(
                Handle, m.WParam, m.LParam, (IRawElementProviderSimple)this);

            return;
        }
        else if (m.LParam == (IntPtr)NativeMethods.OBJID_NATIVEOM)
        {
            IntPtr handle = Marshal.GetComInterfaceForObject(this, typeof(NativeMethods.IOleCommandTarget));
            Guid unknownGuid = typeof(NativeMethods.IUnknown).GUID;
            m.Result = NativeMethods.LresultFromObject(ref unknownGuid, m.WParam, handle);
            return;
        }
    }
    base.WndProc(ref m);
}

public sealed class CommandTargetWindow : NativeWindow,
    NativeMethods.IOleCommandTarget,
    IDisposable
{
    private IWin32Window _parent;

    public CommandTargetWindow(IWin32Window parent)
    {
        _parent = parent;
        base.AssignHandle(parent.Handle);
    }

    [PermissionSetAttribute(SecurityAction.Demand, Unrestricted = true)]
    protected override void WndProc(ref System.Windows.Forms.Message m)
    {
        if (m.Msg == NativeMethods.WM_GETOBJECT)
        {
            //How do I pass back an IOleCommandTarget through the message?
        }
        base.WndProc(ref m);
    }
}

[PermissionSetAttribute(SecurityAction.Demand, Unrestricted = true)]
protected override void WndProc(ref System.Windows.Forms.Message m)
{
    if ((m.Msg == NativeMethods.WM_GETOBJECT) && (m.LParam.ToInt32() == AutomationInteropProvider.RootObjectId))
    {
        m.Result = AutomationInteropProvider.ReturnRawElementProvider(
            Handle, m.WParam, m.LParam, (IRawElementProviderSimple)this);

        return;
    }
    base.WndProc(ref m);
}

[DllImport("oleacc.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern IntPtr LresultFromObject(ref Guid refiid, IntPtr wParam, IntPtr pAcc);

[PermissionSetAttribute(SecurityAction.Demand, Unrestricted = true)]
protected override void WndProc(ref System.Windows.Forms.Message m)
{
    if (m.Msg == (int)NativeMethods.WindowMessage.GETOBJECT)
    {
        if (m.LParam.ToInt32() == AutomationInteropProvider.RootObjectId)
        {
            m.Result = AutomationInteropProvider.ReturnRawElementProvider(
                Handle, m.WParam, m.LParam, (IRawElementProviderSimple)this);

            return;
        }
        else if (m.LParam == (IntPtr)NativeMethods.OBJID_NATIVEOM)
        {
            IntPtr handle = Marshal.GetComInterfaceForObject(this, typeof(NativeMethods.IOleCommandTarget));
            Guid unknownGuid = typeof(NativeMethods.IUnknown).GUID;
            m.Result = NativeMethods.LresultFromObject(ref unknownGuid, m.WParam, handle);
            return;
        }
    }
    base.WndProc(ref m);
}