Qt中如何获取系统图标

Qt中获取系统图标、类型是通过QFileIconProvider来实现的，具体如下：

一、Qt获取系统文件图标

1、获取文件夹图标

QFileIconProvider icon_provider;

QIcon icon = icon_provider.icon(QFileIconProvider::Folder);

2、获取指定文件图标

QFileInfo file_info(name);
QFileIconProvider icon_provider;
QIcon icon = icon_provider.icon(file_info);

二、Windows编程中获取系统图标、类型：

QIcon Setting::getFileIcon(QString file_name)
{
QIcon file_icon = QIcon(":/icon/file");
if(!file_name.isEmpty())
{
  //获取后缀
  std::string str = "file";
  int index = file_name.lastIndexOf(".");
  if(index >= 0)
  {
   QString suffix = file_name.mid(index);

   //将QString转化为std::string
   str = suffix.toUtf8().constData(); //std::string((const char *)path.toLocal8Bit())   path.toLatin1().data();
  }

LPCSTR name = str.c_str();

  SHFILEINFOA info;
  if(SHGetFileInfoA(name,
   FILE_ATTRIBUTE_NORMAL,
   &info,
   sizeof(info),
   SHGFI_SYSICONINDEX | SHGFI_ICON | SHGFI_USEFILEATTRIBUTES))
  {
   HICON icon = info.hIcon;
   file_icon = QIcon(QPixmap::fromWinHICON(icon));
  }
}

return file_icon;
}

QString Setting::getFileType(QString file_name)
{
QString file_type = QString("file");
if(!file_name.isEmpty())
{
  //获取后缀
  std::string str = "file";
  int index = file_name.lastIndexOf(".");
  if(index >= 0)
  {
   QString suffix = file_name.mid(index);

   //将QString转化为std::string
   str = suffix.toUtf8().constData();
  }

LPCSTR name = str.c_str();

  SHFILEINFOA info;
  if(SHGetFileInfoA(name,
   FILE_ATTRIBUTE_NORMAL,
   &info,
   sizeof(info),
   SHGFI_TYPENAME | SHGFI_USEFILEATTRIBUTES))
  {
   std::string type = info.szTypeName;
   file_type = type.c_str();
  }
}

return file_type;
}

QIcon Setting::getFolderIcon()
{
QIcon folder_icon = QIcon(":/icon/folder");

//将QString转化为std::string
std::string str = "folder";
LPCSTR name = str.c_str();

SHFILEINFOA info;
if(SHGetFileInfoA(name,
  FILE_ATTRIBUTE_DIRECTORY,
  &info,
  sizeof(info),
  SHGFI_SYSICONINDEX | SHGFI_ICON | SHGFI_USEFILEATTRIBUTES))
{
  HICON h_icon = info.hIcon;

folder_icon = QIcon(QPixmap::fromWinHICON(h_icon));
}

return folder_icon;
}

QString Setting::getFolderType()
{
QString folder_type = QString("folder");
std::string str = "folder";
LPCSTR name = str.c_str();

SHFILEINFOA info;
if(SHGetFileInfoA(name,
  FILE_ATTRIBUTE_DIRECTORY,
  &info,
  sizeof(info),
  SHGFI_TYPENAME | SHGFI_USEFILEATTRIBUTES))
{
  std::string type = info.szTypeName;
  folder_type = type.c_str();
}

return folder_type;
}