VB中实现ActiveXControl控件IobjectSafety接口


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总述
本文叙述了如何在VB中实现Control控件IobjectSafety接口以标志该Control控件是脚本安全和化安全VBControl控件默认处理方式是在注册表中注册组件类来标识其安全性但实现IobjectSafety接口是更好思路方法本言语包括了实现过程中所需所有代码

请注意Control控件只有确确实实是安全才能被标识为“安全”本文并未论及如何确保Control控件安全性这个问题请参阅Internet Client Software Development Kit (SDK)中相关文档 \"Safe Initialization and Scripting for ActiveX Controls\"它在Component Development 栏目中



相关信息:
<此处略去了段也许无关紧要警告>

现在开始循序渐进地举例介绍说明怎样创建个简单VBControl控件以及怎样将它标识为脚本安全和化安全
首先新建个文件夹来存放在本例中所产生文件

从VB CD-ROM取得OLE 自动化类库制作工具将VB安装光盘中\\Common\\Tools\\VB\\Unsupprt\\Typlib\\目录下所有内容并拷贝到前面新建项目文件夹中


把下列内容拷贝到“记事本”中然后保存到上述文件夹文件名为Objsafe.odl:


[
uuid(C67830E0-D11D-11cf-BD80-00AA00575603),
help(\"VB IObjectSafety Interface\"),
version(1.0)
]
library IObjectSafetyTLB
{
importlib(\"stdole2.tlb\");
[
uuid(CB5BDC81-93C1-11cf-8F20-00805F2CD064),
help(\"IObjectSafety Interface\"),
odl
]
erface IObjectSafety:IUnknown {
[help(\"GetInterfaceSafetyOptions\")]
HRESULT GetInterfaceSafetyOptions(
[in] long riid,
[in] long *pdwSupportedOptions,
[in] long *pdwEnabledOptions);

[help(\"SetInterfaceSafetyOptions\")]
HRESULT SetInterfaceSafetyOptions(
[in] long riid,
[in] long dwOptionsSetMask,
[in] long dwEnabledOptions);
}
}
在命令行提示符下切换到项目文件夹输入下列命令创建个.tlb 文件:


MKTYPLIB objsafe.odl /tlb objsafe.tlb
在VB中新建个ActiveX Control 项目修改属性把项目命名为IobjSafetyControl控件命名为DemoCtl在Control控件上放置个按钮命名为cmdTest在它Click事件中加入句代码 MsgBox \"Test\"


打开菜单“工程->引用”点“浏览”找到刚刚建立Objsafe.tlb把它加入到引用中


增加个新module名为basSafeCtl并在其中加入下列代码:


Option Explicit

Public Const IID_IDispatch = \"{00020400-0000-0000-C000-000000000046}\"
Public Const IID_IPersistStorage = _
\"{0000010A-0000-0000-C000-000000000046}\"
Public Const IID_IPersistStream = _
\"{00000109-0000-0000-C000-000000000046}\"
Public Const IID_IPersistPropertyBag = _
\"{37D84F60-42CB-11CE-8135-00AA004BB851}\"

Public Const INTERFACESAFE_FOR_UNTRUSTED_CALLER = &H1
Public Const INTERFACESAFE_FOR_UNTRUSTED_DATA = &H2


Public Const E_NOINTERFACE = &H80004002
Public Const E_FAIL = &H80004005
Public Const MAX_GUIDLEN = 40

Public Declare Sub CopyMemory Lib \"kernel32\" Alias \"RtlMoveMemory\" _
(pDest As Any, pSource As Any, ByVal ByteLen As Long)
Public Declare Function StringFromGUID2 Lib \"ole32.dll\" (rguid As _
Any, ByVal lpstrClsId As Long, ByVal cbMax As Integer) As Long

Public Type udtGUID
Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(7) As Byte
End Type

Public m_fSafeForScripting As Boolean
Public m_fSafeForInitializing As Boolean

Sub Main
m_fSafeForScripting = True
m_fSafeForInitializing = True
End Sub
在工程属性中把启动对象改成Sub Main确保上述代码会被执行m_fSafeForScripting 和m_fSafeForInitializing两件变量值分别指定了脚本安全和化安全取值


打开Control控件代码窗口在声明部分加入如下代码(如果有Option Explicit语句当然要保证代码放在其后):


Implements IObjectSafety
把下面两个过程代码拷贝到Control控件代码中:


Private Sub IObjectSafety_GetInterfaceSafetyOptions(ByVal riid As _
Long, pdwSupportedOptions As Long, pdwEnabledOptions As Long)

Dim Rc As Long
Dim rClsId As udtGUID
Dim IID As String
Dim bIID As Byte

pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER Or _
INTERFACESAFE_FOR_UNTRUSTED_DATA

If (riid <> 0) Then
CopyMemory rClsId, ByVal riid, Len(rClsId)

bIID = String$(MAX_GUIDLEN, 0)
Rc = StringFromGUID2(rClsId, VarPtr(bIID(0)), MAX_GUIDLEN)
Rc = InStr(1, bIID, vbNullChar) - 1
IID = Left$(UCase(bIID), Rc)

Select Case IID
Case IID_IDispatch
pdwEnabledOptions = IIf(m_fSafeForScripting, _
INTERFACESAFE_FOR_UNTRUSTED_CALLER, 0)
Exit Sub
Case IID_IPersistStorage, IID_IPersistStream, _
IID_IPersistPropertyBag
pdwEnabledOptions = IIf(m_fSafeForInitializing, _
INTERFACESAFE_FOR_UNTRUSTED_DATA, 0)
Exit Sub
Case Else
Err.Raise E_NOINTERFACE


Exit Sub
End Select
End If
End Sub

Private Sub IObjectSafety_SetInterfaceSafetyOptions(ByVal riid As _
Long, ByVal dwOptionsSetMask As Long, ByVal dwEnabledOptions As Long)
Dim Rc As Long
Dim rClsId As udtGUID
Dim IID As String
Dim bIID As Byte

If (riid <> 0) Then
CopyMemory rClsId, ByVal riid, Len(rClsId)

bIID = String$(MAX_GUIDLEN, 0)
Rc = StringFromGUID2(rClsId, VarPtr(bIID(0)), MAX_GUIDLEN)
Rc = InStr(1, bIID, vbNullChar) - 1
IID = Left$(UCase(bIID), Rc)

Select Case IID
Case IID_IDispatch
If ((dwEnabledOptions And dwOptionsSetMask) <> _
INTERFACESAFE_FOR_UNTRUSTED_CALLER) Then
Err.Raise E_FAIL
Exit Sub
Else
If Not m_fSafeForScripting Then
Err.Raise E_FAIL
End If
Exit Sub
End If

Case IID_IPersistStorage, IID_IPersistStream, _
IID_IPersistPropertyBag
If ((dwEnabledOptions And dwOptionsSetMask) <> _
INTERFACESAFE_FOR_UNTRUSTED_DATA) Then
Err.Raise E_FAIL
Exit Sub
Else
If Not m_fSafeForInitializing Then
Err.Raise E_FAIL
End If


Exit Sub
End If

Case Else
Err.Raise E_NOINTERFACE
Exit Sub
End Select
End If
End Sub
保存后把工程编译成OCX文件现在Control控件已经实现了IObjectSafety 接口在.htm中加入这件Control控件试试吧