MFC 获取其他窗口的Edit文本和单击Button

        auto hmain = ::FindWindow(NULL, L"MFCApplication2");
	if (hmain)

	{

		//获取窗口句柄

		CRect rect;

		::GetWindowRect(hmain, rect);

		CString str;
	
		CPoint user_pt;

		//将user_pt点定位到用户名框内

		user_pt.x = rect.left + 109+10;

		user_pt.y = rect.top + 148+10;

	
		//通过位置获取窗口句柄
		auto m_hUserWnd = ::WindowFromPoint(user_pt);

		//通过按钮的名字获取按钮句柄
		HWND  hand_button = ::FindWindowExW(hmain, NULL, TEXT("Button"), TEXT("确定"));//得到按钮的句柄


		str = L"用户名：";

		wchar_t buf[100];

		//获取用户名
		//设置Edit文本
		::SendMessage(m_hUserWnd, WM_SETTEXT, 0, (LPARAM)L"ABC");
		//获取Edit文本
		::SendMessage(m_hUserWnd, WM_GETTEXT, (WPARAM)999, (LPARAM)buf);
		//将剪贴板的内容粘贴到文本框
		::SendMessage(m_hUserWnd, WM_PASTE, 0, 0);

		if (hand_button)
		{
			::PostMessageW(hand_button, WM_LBUTTONDOWN, 0, 0);
			::PostMessageW(hand_button, WM_LBUTTONUP, 0, 0);
		}
		
		str = buf;
		str+=L"\r\n";

		::AfxMessageBox(str);

		

	}

vs2017 测试程序

https://download.youkuaiyun.com/download/u010261063/20042048