TExtension = class(TCefv8HandlerOwn)privateFTestParam: ustring;protectedfunction Execute(const name: ustring; const obj: ICefv8Value;const arguments: TCefv8ValueArray; var retval: ICefv8Value;var exception: ustring): Boolean; override;  //重写Execute事件end;

function TExtension.Execute(const name: ustring; const obj: ICefv8Value;const arguments: TCefv8ValueArray; var retval: ICefv8Value;var exception: ustring): Boolean;
beginif(name = 'SetTestParam') thenbegin// Handle the SetTestParam native function by saving the string argument// into the local member.if (Length(arguments) <> 1) or (not arguments[0].IsString) thenbeginResult := false;Exit;end;FTestParam := arguments[0].GetStringValue;  //多个参数arguments[i].GetStringValue 依次类推Result := true;endelse if(name = 'GetTestParam') thenbegin// Handle the GetTestParam native function by returning the local member// value.retval := TCefv8ValueRef.CreateString(Ftestparam);Result := true;endelse if (name = 'GetTestObject') thenbegin// Handle the GetTestObject native function by creating and returning a// new V8 object.retval := TCefv8ValueRef.CreateObject(nil);// Add a string parameter to the new V8 object.retval.SetValueByKey('param', TCefv8ValueRef.CreateString('Retrieving a parameter on a native object succeeded.'));// Add a function to the new V8 object.retval.SetValueByKey('GetMessage',TCefv8ValueRef.CreateFunction('GetMessage', Self));Result := true;endelse if(name = 'GetMessage') thenbegin// Handle the GetMessage object function by returning a string.retval := TCefv8ValueRef.CreateString('Calling a function on a native object succeeded.');Result := true;end elseResult := false;
end;

procedure RegisterExtension;
varCode: string;
beginCode :='var cef;if(!cef)cef={};if(!cef.taobao)cef.taobao={};(function(){cef.taobao.test_object=function(){native function GetTestObject();return GetTestObject();};})();';if Code <> '' thentryCefRegisterExtension('example/v8',Code,TExtension.Create as ICefv8Handler);exceptend;
end;

chrm1.browser.MainFrame.ExecuteJavaScript('alert("abc");','about:blank',0);

str_temp := 'function aaa(){var CefObj = new cef.taobao.test_object;'+  //先new一个实例对象
               'CefObj.SetTestParam("abc");var b=CefObj.GetTestParam();alert(b);'+   //设置、获取、输出参数
               '}aaa();';
  chrm1.Browser.MainFrame.ExecuteJavaScript(str_temp,'about:blank',0);

如果要实现多个参数，可以定义个数组替代FTestParam 

private
    FTestParam : ustring;
    ArrayParam : array of ustring;  //多个参数

关键代码：

if(name = 'SetTestParam') thenbegin
// **************原来一个参数的情况**********
//    if (Length(arguments) <> 1) or (not arguments[0].IsString) then
//    begin
//      Result := false;
//      Exit;
//    end;
//    FTestParam  := arguments[0].GetStringValue;
// **************原来一个参数的情况**********
    SetLength(ArrayParam,Length(arguments));for  i := 0 to Length(arguments) - 1 dobeginArrayParam[i] := arguments[i].GetStringValue;if s='' thens := ArrayParam[i]elses  := s+','+ArrayParam[i];end;FTestParam  := s;endelse if(name = 'GetTestParam') thenbegin
// **************原来一个参数的情况**********
//    retval := TCefv8ValueRef.CreateString(FTestParam);
// **************原来一个参数的情况**********for  i := 0 to Length(ArrayParam) - 1 dobeginif s='' thens := ArrayParam[i]elses  := s+','+ArrayParam[i];end;retval := TCefv8ValueRef.CreateString(FTestParam);end;

这样调用GetTestParam返回的还是一个字符串，多个参数用逗号隔开了而已，可以对其再进行改写即可；