修改window.external使JS可调用Delphi方法

原文地址：http://hi.baidu.com/rarnu/blog/item/4ec80608022766d663d986ea.html

在js中，有一个比较特殊的对象，即window.external，用它可以调用浏览器提供的外部方法
一个很简单的例子就是将当前页添加到收藏夹
window.external.addFavorite("http://blog.csdn.NET/youthon","弘石的博客');
这样写脚本就可以了。
那么如果我想自己定义external，以便在自己的软件内使用IE核心的浏览器作为UI容器，该如何做呢？
本文即是解决此问题。
一、制作TLB
在File | New | Other 菜单下，选择新建一个Type Library，这个向导在ActiveX页内。
然后按下图所示，新建一个接口，在接口下新建一个DoSearchData方法，这个方法即是将来需要添加到external中的。

完成添加后，点击保存为TLB按钮，将生成一个TLB文件，此处我将它命名为GetData.tlb
二、实现IDocHostUIHandler接口
这部分相对比较简单，从MSDN上找到相关的C++代码，把它转换成Delphi的即可。代码如下：
 unitDocHostUIHandler;

 interface
 uses
 Windows, ActiveX;
 const
 DOCHOSTUIFLAG_DIALOG                     =$00000001;
 DOCHOSTUIFLAG_DISABLE_HELP_MENU          =$00000002;
 DOCHOSTUIFLAG_NO3DBORDER                 =$00000004;
 DOCHOSTUIFLAG_SCROLL_NO                  =$00000008;
 DOCHOSTUIFLAG_DISABLE_SCRIPT_INACTIVE    = $00000010;
 DOCHOSTUIFLAG_OPENNEWWIN                 =$00000020;
 DOCHOSTUIFLAG_DISABLE_OFFSCREEN          =$00000040;
 DOCHOSTUIFLAG_FLAT_SCROLLBAR             =$00000080;
 DOCHOSTUIFLAG_DIV_BLOCKDEFAULT           =$00000100;
 DOCHOSTUIFLAG_ACTIVATE_CLIENTHIT_ONLY    = $00000200;
 DOCHOSTUIFLAG_OVERRIDEBEHAVIORFACTORY    = $00000400;
 DOCHOSTUIFLAG_CODEPAGELINKEDFONTS        =$00000800;
 DOCHOSTUIFLAG_URL_ENCODING_DISABLE_UTF8  = $00001000;
 DOCHOSTUIFLAG_URL_ENCODING_ENABLE_UTF8   = $00002000;
 DOCHOSTUIFLAG_ENABLE_FORMS_AUTOCOMPLETE  = $00004000;
 DOCHOSTUIFLAG_ENABLE_INPLACE_NAVIGATION  = $00010000;
 DOCHOSTUIFLAG_IME_ENABLE_RECONVERSION    = $00020000;
 DOCHOSTUIFLAG_THEME                      =$00040000;
 DOCHOSTUIFLAG_NOTHEME                    =$00080000;
 DOCHOSTUIFLAG_NOPICS                     =$00100000;
 DOCHOSTUIFLAG_NO3DOUTERBORDER            =$00200000;
 DOCHOSTUIFLAG_DISABLE_EDIT_NS_FIXUP      = $1;
 DOCHOSTUIFLAG_LOCAL_MACHINE_ACCESS_CHECK =$1;
 DOCHOSTUIFLAG_DISABLE_UNTRUSTEDPROTOCOL  = $1;
 DOCHOSTUIDBLCLK_DEFAULT        = 0;
 DOCHOSTUIDBLCLK_SHOWPROPERTIES = 1;
 DOCHOSTUIDBLCLK_SHOWCODE       = 2;
 DOCHOSTUITYPE_BROWSE = 0;
 DOCHOSTUITYPE_AUTHOR = 1;

 type
 TDocHostUIInfo = record
    cbSize: ULONG;
    dwFlags: DWORD;
    dwDoubleClick: DWORD;
    pchHostCss: PWChar;
    pchHostNS: PWChar;
 end;
 PDocHostUIInfo = ^TDocHostUIInfo;
 IDocHostUIHandler = interface(IUnknown)
    ['{bd3f23c0-d43e-11cf-893b-00aa00bdce1a}']
    functionShowContextMenu(const dwID:DWORD;constppt: PPOINT;
      constpcmdtReserved:IUnknown;constpdispReserved: IDispatch): HResult;
      stdcall;
    functionGetHostInfo(var pInfo:TDocHostUIInfo): HResult;stdcall;
    functionShowUI(const dwID:DWORD;
      constpActiveObject: IOleInPlaceActiveObject;
      constpCommandTarget: IOleCommandTarget;const pFrame:IOleInPlaceFrame;
      constpDoc: IOleInPlaceUIWindow): HResult;stdcall;
    function HideUI:HResult;stdcall;
    function UpdateUI:HResult;stdcall;
    functionEnableModeless(const fEnable:BOOL):HResult;stdcall;
    functionOnDocWindowActivate(const fActivate:BOOL):HResult;stdcall;
    functionOnFrameWindowActivate(const fActivate:BOOL):HResult;stdcall;
    functionResizeBorder(const prcBorder:PRECT;
      constpUIWindow: IOleInPlaceUIWindow;const fFrameWindow:BOOL):HResult;
      stdcall;
    functionTranslateAccelerator(const lpMsg: PMSG;constpguidCmdGroup: PGUID;
      constnCmdID:DWORD): HResult;stdcall;
    functionGetOptionKeyPath(var pchKey:POLESTR;const dw:DWORD): HResult;
      stdcall;
    functionGetDropTarget(const pDropTarget:IDropTarget;
      out ppDropTarget: IDropTarget): HResult; stdcall;
    functionGetExternal(out ppDispatch: IDispatch): HResult;stdcall;
    functionTranslateUrl(const dwTranslate:DWORD;constpchURLIn: POLESTR;
      varppchURLOut: POLESTR): HResult;stdcall;
    functionFilterDataObject(const pDO:IDataObject;
      out ppDORet: IDataObject): HResult; stdcall;
    end;

 implementation

 end.
三、实现一个带有IE组件的容器
由于Delphi自带的WebBrowser控件不支持external的直接扩展，因此我们需要另外写一个容器，使它实现IDocHostUIHandler接口，并且通过ActiveX单元的IOleObject.SetClientSite方法，将我们自己的容器填充进去。
这部分的代码直接参考了EmbeddedWB组件的相关实现，具体代码如下：
unit NulContainer;

interface

uses
Windows, ActiveX, SHDocVw, DocHostUIHandler;

type
TNulWBContainer = class(TObject,
    IUnknown,IOleClientSite, IDocHostUIHandler)
private
   fHostedBrowser: TWebBrowser;
    procedureSetBrowserOleClientSite(const Site: IOleClientSite);
protected
    functionQueryInterface(const IID: TGUID; out Obj): HResult; stdcall;
    function_AddRef: Integer; stdcall;
    function_Release: Integer; stdcall;
    functionSaveObject: HResult; stdcall;
    functionGetMoniker(dwAssign: Longint;
     dwWhichMoniker: Longint;
     out mk: IMoniker): HResult; stdcall;
    functionGetContainer(
     out Container: IOleContainer): HResult; stdcall;
    functionShowObject: HResult; stdcall;
    functionOnShowWindow(fShow: BOOL): HResult; stdcall;
    functionRequestNewObjectLayout: HResult; stdcall;
    functionShowContextMenu(const dwID: DWORD; const ppt: PPOINT;
     const pcmdtReserved: IUnknown; const pdispReserved: IDispatch):HResult;
     stdcall;
    functionGetHostInfo(var pInfo: TDocHostUIInfo): HResult; stdcall;
    functionShowUI(const dwID: DWORD;
     const pActiveObject: IOleInPlaceActiveObject;
     const pCommandTarget: IOleCommandTarget; const pFrame:IOleInPlaceFrame;
     const pDoc: IOleInPlaceUIWindow): HResult; stdcall;
    functionHideUI: HResult; stdcall;
    functionUpdateUI: HResult; stdcall;
    functionEnableModeless(const fEnable: BOOL): HResult; stdcall;
    functionOnDocWindowActivate(const fActivate: BOOL): HResult; stdcall;
    functionOnFrameWindowActivate(const fActivate: BOOL): HResult;stdcall;
    functionResizeBorder(const prcBorder: PRECT;
     const pUIWindow: IOleInPlaceUIWindow; const fFrameWindow: BOOL):HResult;
     stdcall;
    functionTranslateAccelerator(const lpMsg: PMSG; const pguidCmdGroup:PGUID;
     const nCmdID: DWORD): HResult; stdcall;
    functionGetOptionKeyPath(var pchKey: POLESTR; const dw: DWORD ):HResult;
     stdcall;
    functionGetDropTarget(const pDropTarget: IDropTarget;
     out ppDropTarget: IDropTarget): HResult; stdcall;
    functionGetExternal(out ppDispatch: IDispatch): HResult; stdcall;
    functionTranslateUrl(const dwTranslate: DWORD; const pchURLIn:POLESTR;
     var ppchURLOut: POLESTR): HResult; stdcall;
    functionFilterDataObject(const pDO: IDataObject;
     out ppDORet: IDataObject): HResult; stdcall;
public
    constructorCreate(const HostedBrowser: TWebBrowser);
    destructorDestroy; override;
    propertyHostedBrowser: TWebBrowser read fHostedBrowser;
end;

implementation

uses
SysUtils;

{ TNulWBContainer }

constructor TNulWBContainer.Create(const HostedBrowser:TWebBrowser);
begin
Assert(Assigned(HostedBrowser));
inherited Create;
fHostedBrowser := HostedBrowser;
SetBrowserOleClientSite(Self as IOleClientSite);
end;

destructor TNulWBContainer.Destroy;
begin
SetBrowserOleClientSite(nil);
inherited;
end;

function TNulWBContainer.EnableModeless(const fEnable: BOOL):HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.FilterDataObject(const pDO:IDataObject;
out ppDORet: IDataObject): HResult;
begin
ppDORet := nil;
Result := S_FALSE;
end;

function TNulWBContainer.GetContainer(
out container: IOleContainer): HResult;
begin
container := nil;
Result := E_NOINTERFACE;
end;

function TNulWBContainer.GetDropTarget(const pDropTarget:IDropTarget;
out ppDropTarget: IDropTarget): HResult;
begin
ppDropTarget := nil;
Result := E_FAIL;
end;

function TNulWBContainer.GetExternal(out ppDispatch: IDispatch):HResult;
begin
ppDispatch := nil;
Result := E_FAIL;
end;

function TNulWBContainer.GetHostInfo(var pInfo: TDocHostUIInfo):HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.GetMoniker(dwAssign, dwWhichMoniker:Integer;
out mk: IMoniker): HResult;
begin
mk := nil;
Result := E_NOTIMPL;
end;

function TNulWBContainer.GetOptionKeyPath(var pchKey:POLESTR;
const dw: DWORD): HResult;
begin
Result := E_FAIL;
end;

function TNulWBContainer.HideUI: HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.OnDocWindowActivate(
const fActivate: BOOL): HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.OnFrameWindowActivate(
const fActivate: BOOL): HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.OnShowWindow(fShow: BOOL):HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.QueryInterface(const IID: TGUID; outObj): HResult;
begin
if GetInterface(IID, Obj) then
    Result :=S_OK
else
    Result :=E_NOINTERFACE;
end;

function TNulWBContainer.RequestNewObjectLayout: HResult;
begin
Result := E_NOTIMPL;
end;

function TNulWBContainer.ResizeBorder(const prcBorder:PRECT;
const pUIWindow: IOleInPlaceUIWindow; const fFrameWindow: BOOL):HResult;
begin
Result := S_FALSE;
end;

function TNulWBContainer.SaveObject: HResult;
begin
Result := S_OK;
end;

procedure TNulWBContainer.SetBrowserOleClientSite(
const Site: IOleClientSite);
var
OleObj: IOleObject;
begin
Assert((Site = Self as IOleClientSite) or (Site = nil));
if not Supports(fHostedBrowser.DefaultInterface, IOleObject,OleObj) then
    raiseException.Create('Browser''s Default interface does not supportIOleObject');
OleObj.SetClientSite(Site);
end;

function TNulWBContainer.ShowContextMenu(const dwID:DWORD;
const ppt: PPOINT; const pcmdtReserved: IInterface;
const pdispReserved: IDispatch): HResult;
begin
Result := S_FALSE
end;

function TNulWBContainer.ShowObject: HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.ShowUI(const dwID: DWORD;
const pActiveObject: IOleInPlaceActiveObject;
const pCommandTarget: IOleCommandTarget; const pFrame:IOleInPlaceFrame;
const pDoc: IOleInPlaceUIWindow): HResult;
begin
Result := S_OK;
end;

function TNulWBContainer.TranslateAccelerator(const lpMsg:PMSG;
const pguidCmdGroup: PGUID; const nCmdID: DWORD): HResult;
begin
Result := S_FALSE;
end;

function TNulWBContainer.TranslateUrl(const dwTranslate:DWORD;
const pchURLIn: POLESTR; var ppchURLOut: POLESTR): HResult;
begin
Result := E_FAIL;
end;

function TNulWBContainer.UpdateUI: HResult;
begin
Result := S_OK;
end;

function TNulWBContainer._AddRef: Integer;
begin
Result := -1;
end;

function TNulWBContainer._Release: Integer;
begin
Result := -1;
end;

end.

http://blog.csdn.net/youthon/article/details/8446135