How to fix error atl/mfc atlcomcli.h line 291 vscode 2022

Question

hello guys,

I'm new developer and I want to get my active url for google chrome for my project tracking.

I run code in this answer :

https://stackoverflow.com/questions/48504300/get-active-tab-url-in-chrome-with-c

But when run code, I got error from atl library :

File: C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.36.32532\atlmfc\include\atlcomcli.h
Line: 291
Expression: p == 0

Please help me to fix it.

Another , I hope to can build project like this

gcc mycode.cpp -o mycode -latl

Thank you

Answer 1

The ATL source code ASSERTS because uia.CoCreateInstance is called twice. After the first successful call the uia smart pointer variable contains an IUIAutomation interface pointer in member variable p. In a debug build the ATL source code call ATLASSERT to alert that the CComPtr::CoCreateInstance member function has been called on a smart pointer that has already been initialized.

Adjust the code so that uia.CoCreateInstance is only called once if it is successful.

Answer 2

here is my code

#include "iostream"

#include <Windows.h>
#include <stdio.h>
#include <AtlBase.h>
#include <AtlCom.h>
#include <UIAutomation.h>

bool find_url(IUIAutomation* uia, IUIAutomationElement* root)
{
    std::cout << "find_url starting ..." << std::endl;

    // The root window has several childs, 
    // one of them is a "pane" named "Google Chrome"
    // This contains the toolbar. Find this "Google Chrome" pane:
    CComPtr<IUIAutomationElement> pane;
    CComPtr<IUIAutomationCondition> pane_cond;
    uia->CreatePropertyCondition(UIA_ControlTypePropertyId,
        CComVariant(UIA_PaneControlTypeId), &pane_cond);

    CComPtr<IUIAutomationElementArray> arr;
    if FAILED(root->FindAll(TreeScope_Children, pane_cond, &arr))
        return false;

    int count = 0;
    arr->get_Length(&count);
    std::cout << "start find_url count " << count << std::endl;

    for (int i = 0; i < count; i++)
    {
        CComBSTR name;
        if SUCCEEDED(arr->GetElement(i, &pane))
            std::cout << "start find_url pane  " << pane << std::endl;
        if SUCCEEDED(pane->get_CurrentName(&name))
            std::wcout << "start find_url pane name " << name.m_str << std::endl;
        if (wcscmp(name, L"Chrome Legacy Window") == 0)
                    break;
        pane.Release();
    }

    std::cout << "find_url panel chrome " << pane << std::endl;
    if (!pane)
        return false;

    std::cout << "find_url gg chrome panel existed " << pane << " count : " << count << std::endl;

    //look for first UIA_EditControlTypeId under "Google Chrome" pane
    CComPtr<IUIAutomationElement> url;
    CComPtr<IUIAutomationCondition> url_cond;
    uia->CreatePropertyCondition(UIA_ControlTypePropertyId,
        CComVariant(UIA_EditControlTypeId), &url_cond);
    if FAILED(pane->FindFirst(TreeScope_Descendants, url_cond, &url))
        return false;
    std::cout << "CreatePropertyCondition url " << url << std::endl;

    //get value of `url`
    CComVariant var;
    if FAILED(url->GetCurrentPropertyValue(UIA_ValueValuePropertyId, &var))
        return false;
    if (!var.bstrVal)
        return false;
    wprintf(L"find_url: %s\n", var.bstrVal);

    //set new address ...
    IValueProvider* pattern = nullptr;
    if (FAILED(url->GetCurrentPattern(UIA_ValuePatternId, (IUnknown**)&pattern)))
        return false;
    //pattern->SetValue(L"somewhere.com");
    pattern->Release();

    INPUT input[2] = { INPUT_KEYBOARD };
    input[0].ki.wVk = VK_RETURN;
    input[1] = input[0];
    input[1].ki.dwFlags |= KEYEVENTF_KEYUP;
    SendInput(2, input, sizeof(INPUT));

    return true;
}

int main() {
	std::cout << "hello world" << std::endl;

    HWND hwnd = nullptr;
    while (true)
    {
        hwnd = FindWindowEx(nullptr, hwnd, L"Chrome_WidgetWin_1", nullptr);
        if (!hwnd)
            return 0;
        if (IsWindowVisible(hwnd) && GetWindowTextLength(hwnd) > 0)
            break;
    }
    std::cout << "CoInitializeEx" << std::endl;

    //CoInitializeEx(nullptr, COINIT_MULTITHREADED);//<- pick the right one
    CoInitializeEx(nullptr, COINIT_MULTITHREADED);
    CComPtr<IUIAutomation> uia;
    while (true) {
        unsigned int miliseconds = 1000;
        Sleep(miliseconds);
        
        std::cout << "SUCCEEDED start : " << SUCCEEDED(uia.CoCreateInstance(CLSID_CUIAutomation)) << std::endl;

        if SUCCEEDED(uia.CoCreateInstance(CLSID_CUIAutomation))
        {
            CComPtr<IUIAutomationElement> root;
            if SUCCEEDED(uia->ElementFromHandle(hwnd, &root))
                find_url(uia, root);
        }
    }

     uia.Release();

    CoUninitialize();
	return 1;
}

Answer 3

O erro que você está vendo é provavelmente um erro de assertiva de tempo de execução. Em C++, assertivas são usadas para declarar condições que são verdadeiras, de modo que, se a condição for falsa, o programa irá parar.