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;
}
效果图：
两种方式最大的区别是什么呢？
可以参考这篇文章—QFileIconProvider, Getting icon for non-existent file (based on extension)！诸如所言，Qt所提供的获取图标的方法是本地已存在的文件，如果要通过扩展名来获取图标则需要自己来虚拟构造本地文件，而在数据量较大的情况下往往会影响性能。这（通过扩展名获取图标、类型）可以通过Windows API来实现，即方法二。
