关于.net:如何将控件投射到IOleObject

 2021-04-26 

How to cast a control to IOleObject

我想在.net控件上调用GetClientSite。为此,我试图将控件(例如Windows.Forms.Form)转换为返回null的IOleObject。

如何获取IOleObject?

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
using System;
using System.Runtime.InteropServices;
using System.Security;
using System.Windows.Forms;

namespace Test001
{
    public class Form001 : Form
    {
        public Form001()
        {
            InitializeComponent();
        }

        private void InitializeComponent()
        {
            this.SuspendLayout();
            this.Name ="Form001";
            this.Text ="Form001";
            this.Load += new System.EventHandler(this.Form001_Load);
            this.ResumeLayout(false);
        }

        private void Form001_Load(object sender, EventArgs e)
        {
            IOleObject obj = (IOleObject) this;
            //IOleClientSite site = obj.GetClientSite();
        }
    }

    [ComImport, Guid("00000112-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), SuppressUnmanagedCodeSecurity]
    public interface IOleObject
    {
        [PreserveSig]
        int SetClientSite([In, MarshalAs(UnmanagedType.Interface)] IOleClientSite pClientSite);
        IOleClientSite GetClientSite();
        [PreserveSig]
        int SetHostNames([In, MarshalAs(UnmanagedType.LPWStr)] string szContainerApp, [In, MarshalAs(UnmanagedType.LPWStr)] string szContainerObj);
        [PreserveSig]
        int Close(int dwSaveOption);
        [PreserveSig]
        int SetMoniker([In, MarshalAs(UnmanagedType.U4)] int dwWhichMoniker, [In, MarshalAs(UnmanagedType.Interface)] object pmk);
        [PreserveSig]
        int GetMoniker([In, MarshalAs(UnmanagedType.U4)] int dwAssign, [In, MarshalAs(UnmanagedType.U4)] int dwWhichMoniker, [MarshalAs(UnmanagedType.Interface)] out object moniker);
        [PreserveSig]
        int InitFromData([In, MarshalAs(UnmanagedType.Interface)] IDataObject pDataObject, int fCreation, [In, MarshalAs(UnmanagedType.U4)] int dwReserved);
        [PreserveSig]
        int GetClipboardData([In, MarshalAs(UnmanagedType.U4)] int dwReserved, out IDataObject data);
        [PreserveSig]
        int DoVerb(int iVerb, [In] IntPtr lpmsg, [In, MarshalAs(UnmanagedType.Interface)] IOleClientSite pActiveSite, int lindex, IntPtr hwndParent, [In] object lprcPosRect);
        [PreserveSig]
        int EnumVerbs(out object e);
        [PreserveSig]
        int OleUpdate();
        [PreserveSig]
        int IsUpToDate();
        [PreserveSig]
        int GetUserClassID([In, Out] ref Guid pClsid);
        [PreserveSig]
        int GetUserType([In, MarshalAs(UnmanagedType.U4)] int dwFormOfType, [MarshalAs(UnmanagedType.LPWStr)] out string userType);
        [PreserveSig]
        int SetExtent([In, MarshalAs(UnmanagedType.U4)] int dwDrawAspect, [In] object pSizel);
        [PreserveSig]
        int GetExtent([In, MarshalAs(UnmanagedType.U4)] int dwDrawAspect, [Out] object pSizel);
        [PreserveSig]
        int Advise(object pAdvSink, out int cookie);
        [PreserveSig]
        int Unadvise([In, MarshalAs(UnmanagedType.U4)] int dwConnection);
        [PreserveSig]
        int EnumAdvise(out object e);
        [PreserveSig]
        int GetMiscStatus([In, MarshalAs(UnmanagedType.U4)] int dwAspect, out int misc);
        [PreserveSig]
        int SetColorScheme([In] object pLogpal);
    }

    [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("00000118-0000-0000-C000-000000000046")]
    public interface IOleClientSite
    {
        [PreserveSig]
        int SaveObject();
        [PreserveSig]
        int GetMoniker([In, MarshalAs(UnmanagedType.U4)] int dwAssign, [In, MarshalAs(UnmanagedType.U4)] int dwWhichMoniker, [MarshalAs(UnmanagedType.Interface)] out object moniker);
        [PreserveSig]
        int GetContainer(out object container);
        [PreserveSig]
        int ShowObject();
        [PreserveSig]
        int OnShowWindow(int fShow);
        [PreserveSig]
        int RequestNewObjectLayout();
    }
}

IOleObject接口是System.Windows.Forms程序集中的内部UnsafeNativeMethods类内的嵌套接口。 System.Windows.Forms.Control在内部明确地实现它。

创建另一个具有相同名称和guid的界面不会使其在托管级别上成为"相同的界面"。

此行

1
IOleObject obj = (IOleObject) this;

表示托管的.net强制转换,与COM无关。此强制转换只能与winforms程序集中完全相同的接口一起使用,该接口是不公开的。

您可以尝试通过InterfaceMapping结构使用反射来获取方法(但请注意,这是不推荐的):

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Type thisType = this.GetType();

Type oleInterface = thisType.GetInterface("IOleObject");

MethodInfo getSiteMethod = oleInterface.GetMethod("GetClientSite");

//InterfaceMapping is used to get more complex interface scenarios
InterfaceMapping map = thisType.GetInterfaceMap(oleInterface);

//at which index is the explicit implementation
int index = Array.IndexOf(map.InterfaceMethods, getSiteMethod);
MethodInfo actualExplicitMethod = map.TargetMethods[index];

//late-bound call (slow)
object o = actualExplicitMethod.Invoke(this, new object[] { });

现在,首先,您获得一个package在System.Object中的内部类型,由于原始接口是内部接口,因此无法转换为您的接口,因此,只要您打算使用该对象,就可以通过反射获得更多的乐趣。

第二,我已经尝试过了,该技术有效,但是在您的特定情况下,在Windows窗体上调用的此方法会引发异常-"Top-level Windows Forms control cannot be exposed as an ActiveX control."


这是另一种使用Marshal.CreateAggregatedObject进入专用COM接口的方法。


我正在使用此方法:

1
IOleClientSite pClientSite = (IOleClientSite)Site.GetService(new AntiMoniker().GetType());

例如,

定义AntiMoniker。目前,不需要详细信息。只需获取System .__ ComObject的实例。

1
2
3
[ComImport(), Guid("00000305-0000-0000-C000-000000000046")]
class AntiMoniker {
}

它将在.NET Framework 2.0 / IE8 / WinXP SP3上运行

谢谢