CComDispatchDriver InvokeN以result.lVal = -858993460返回Result [英] CComDispatchDriver InvokeN Returns Result with result.lVal = -858993460
问题描述
我正在尝试为Atl BHO（c ++）中的JavaScript Window.postMessage添加Window.PostMessage侦听器。
代码添加事件处理程序..
$
DISPID dispidAddEventListener = -1;
  if（FAILED（dispWindow.GetIDOfName（CComBSTR（" addEventListener"））& dispidAddEventListener））））
  {
  //失败..
 返回;
}
CListener * eventHandler;
$
if（FAILED（CListener :: Create（this，& eventHandler））） />
{
  //无法创建事件接收器
 返回;
}
IDispatch * eventHandlerAsDispatch;
if（FAILED（eventHandler-> QueryInterface（IID_IDispatch，reinterpret_cast< void **> （& eventHandlerAsDispatch）））））
{
&NBSP; //无法获取事件接收器的IDispatch指针
&NBSP;返回;
}
CComVariant结果;
CComVariant invokeParams [3];
invokeParams [0] = CComVariant （false）;
$
invokeParams [1] = CComVariant（eventHandlerAsDispatch）;
invokeParams [2] = CComVariant（L" message"）;
if（FAILED（dispWindow.InvokeN（dispidAddEventListener，invokeParams，3，& result））））
{
&NBSP; //无法调用addEventListener方法
&NBSP;返回;
}
if（FAILED（result.lVal））//在这里失败...
{
&NBSP;返回;
$
}
但执行dispWindow.InvokeN后，result.lVal始终为-858993460，addEventListener失败。
任何想法上面的代码有什么问题。
Ashish Shivhare
I am trying to add Window.PostMessage listener for JavaScript Window.postMessage inside Atl BHO (c++).
Code for adding event handler..
DISPID dispidAddEventListener = -1;
if (FAILED(dispWindow.GetIDOfName(CComBSTR("addEventListener"), &dispidAddEventListener)))
{
//failed..
return;
}
CListener* eventHandler;
if (FAILED(CListener::Create(this, &eventHandler)))
{
// Could not create the event sink
return;
}
IDispatch* eventHandlerAsDispatch;
if (FAILED(eventHandler->QueryInterface(IID_IDispatch, reinterpret_cast<void**>(&eventHandlerAsDispatch))))
{
//Could not get an IDispatch pointer for the event sink
return;
}
CComVariant result;
CComVariant invokeParams[3];
invokeParams[0] = CComVariant(false);
invokeParams[1] = CComVariant(eventHandlerAsDispatch);
invokeParams[2] = CComVariant(L"message");
if (FAILED(dispWindow.InvokeN(dispidAddEventListener, invokeParams, 3, &result)))
{
//Could not invoke the addEventListener method
return;
}
if (FAILED(result.lVal)) //failing here...
{
return;
}
But after executing dispWindow.InvokeN The result.lVal is always -858993460, and addEventListener fails.
Any ideas what is wrong with above code.
Ashish Shivhare
推荐答案
2017年4月6日下午2:44 ，Ashish Shivhare写道：
On 4/6/2017 2:44 PM, Ashish Shivhare wrote:
if（FAILED（dispWindow.InvokeN（dispidAddEventListener，invokeParams，3，& result））））
{
&NBSP; //无法调用addEventListener方法
&NBSP;返回;
}
if（FAILED（lVal））//在这里失败...
if (FAILED(dispWindow.InvokeN(dispidAddEventListener, invokeParams, 3, &result)))
{
//Could not invoke the addEventListener method
return;
}
if (FAILED(lVal)) //failing here...
addEventListener不返回任何值。结果很可能是VT_EMPTY类型。成功或失败通过invokeN调用的返回值指示，您已经检查过。
addEventListener doesn't return any value. result is most likely of type VT_EMPTY. The success or failure is indicated via the return value of invokeN call, which you already check.
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