Shulou(Shulou.com)06/03 Report--

Recently, people around me are crazy about QT, which affects me, so I found several better websites when I was learning QT.

Chinese official website: http://qt.nokia.com/title-cn/

Http://leenux.cublog.cn/

Http://www.qtkbase.com/

Http://wiki.ubuntu.org.cn/Qt

Http://hi.baidu.com/cyclone/home

Http://qt.csdn.net/

Http://www.thisisqt.com/forum/index.php

Http://blog.csdn.net/qter_wd007#

Http://www.qiliang.net/blog/#

Http://hi.baidu.com/xchinux#

Http://www.cuteqt.com/blog/?author=4#

Http://www.qtcn.org

Http://blogold.chinaunix.net/u2/67823/

Http://qt.nokia.com

Http://www.qteverywhere.com

Http://www.oschina.net/p/qt

Book recommendation: C.GUI.Qt.4 programming Electronics Industry Press

Attached: brief introduction of QT

Introduction: Qt is a cross-platform C++ graphical user interface library, produced by TrollTech, Norway, currently including Qt, Framebuffer-based Qt Embedded, rapid development tools Qt Designer, internationalization tools Qt Linguist and other parts of Qt support all Unix systems, including Linux, but also support the WinNT/Win2k,Win95/98 platform.

Trolltech was founded in 1994, but in 1992, the programmers who founded Trolltech began to design Qt. The first commercial version of Qt was launched in 1995 and Qt developed rapidly. Here are some milestones in the history of Qt:

1996 Oct KDE organizes 1998 Apr 05 Trolltech programmers to migrate Netscape5.0 from Motif to Qt 1998 Apr 08 KDE Free Qt Foundation sets up 1998 Jul 09 Qt 1.40 release 1998 Jul 12 KDE 1.0 release 1999 Mar 04 QPL 1.0 release 1999 Mar 12 Qt 1.44 release 1999 Jun 25 Qt 2.0 release 1999 Sep 13 KDE 1.1.2 release 2000 Mar 20 embedded Qt release 2000 Sep 06 Qt 2.2 release 2000 Oct 05 Qt 2.2.1 release 2000 Oct 30 Qt/Embedded start using GPL Manifesto 2000 Sep 04 Qt free edition start using GPL

Basically, Qt is the same type of thing as graphical interface libraries such as Motif,Openwin,GTK on X Window and MFC,OWL,VCL,ATL on Windows platforms, but Qt has the following advantages:

Excellent cross-platform features:

Qt supports the following operating systems: Microsoft Windows 95gam98, Microsoft Windows NT, Linux, Solaris, SunOS, HP-UX, Digital UNIX (OSF/1, Tru64), Irix, FreeBSD, BSD/OS, SCO, AIX, OS390,QNX and so on.

object-oriented

The good encapsulation mechanism of Qt makes Qt very modular and reusable, which is very convenient for user development. Qt provides a security type called signals/slots instead of callback, which makes it easy to work together among components.

Rich API

Qt includes more than 250 C++ classes, as well as template-based collections, serialization, file, I device O device, directory management, date/time classes. It even includes regular expression processing.

Support 2D/3D graphics rendering, support OpenGL

A large number of development documents

XML support

But what really makes Qt stand out among many Widgets in the free software world (such as Lesstif,Gtk,EZWGL,Xforms,fltk, etc.) is the Qt-based heavyweight software KDE. Interestingly, KDE is also a reason why Trolltech is under a lot of pressure. Let's take a look at how this famous free software jihad-"KDE/QT. Vs. Gnome/Gtk" happened in the future.

The graphical interface of Unix has always been based on MIT's X Window system, but there are two major schools in commercial applications, one is the Openlook camp led by Sun, and the other is the Motif of OSF (Open Software Foundation) led by IBM/HP. After years of competition, Motif finally won and became the most commonly used interface library, and then the two sides compromised a CDE (Common Desktop Enviroment) as a standard graphical interface. But the price of Motif/CDER is very expensive, while Microsoft's Windows graphical interface is developing very fast, and Linux, a rising star in the Unix world, is in urgent need of a reliable and free graphical interface.

In October 1996, Matthias Ettrich, a German who developed the graphic typesetting tool Lyx, launched the KDE project. The full name of KDE is K Desktop Environment, and you can see that it is aimed at CDE. KDE itself uses the GPL manifesto, but KDE uses Qt as its underlying library, because Qt has released its Unix version freely at that time, but Qt does not follow GPL, so KDE is thought by many free software authors that the use of off-the-shelf software development is against the spirit of GPL, so the fanatic followers of GNU split up one way to make Harmonny, trying to rewrite a set of Qt-compatible alternatives. The other way is to redevelop a set called GNOME (GNU Network Object Enviroment) to replace KDE under the leadership of Miguel De Icaza, a 26-year-old Mexican programmer.

Because RedHat, the leader of the Linux world, didn't like the copyright of KDE/Qt, RedHat even sent several full-time programmers to join GNOME to develop, so a jihad similar to Motif VS Openlook began. Trolltech has modified the copyright of Qt several times for KDE, from the establishment of the KDE Free Qt foundation to the adoption of QPL, but the GTK adopted by GNOME is completely GPL from the very beginning, so GNOME has certain advantages in this side, plus Qt/KDE uses C++ development, the entry threshold is relatively high, and GTK/Gnome uses C, so GNOME has attracted more free software developers, but KDE has taken the lead after all. The KDE1.1.2 launched is very stable, and the system stability of GNOME1.0, which was launched in a hurry at that time, is so poor that some people even laugh that GNOME1.0 is not as stable as KDE 1.0 Alpha. However, GNOME has developed rapidly since then, and there is a great momentum to catch up. At that time, the developers of both sides were so hyped on the Internet that even Linus, the father of Linux, was criticized for saying that he liked to use KDE.

In the third year of the war, in 2000, the situation changed, and one major event occurred one after another: first, a group of engineers from Apple set up a company called Eazel to design the interface for GNOME, then a group of GNOME programmers set up a Helix Code company to provide business support for GNOME, and the long-awaited KDE 2.0 was finally released. This is probably one of the largest free software at present. In addition to KDE itself, it also includes a large number of software, such as Koffice suite, and Kdevelop, the integrated development environment. Its main software, Kounqueror, is also the first browser that can compete with Microsoft's Internet Exploer. While Sun, Red Hat, Eazel, Helix Code and other companies set up a GNOME foundation, Sun also announced that it would integrate the heavyweight office software Star office with GNOME, so Trolltech naturally could not sit back and wait for death. On October 4 this year, it turned Qt's free edition into a GPL manifesto, which thoroughly solved the copyright problem of KDE, and launched embedded Qt, which gave the GNOME camp a strong counterattack.

Up to now, the war is still going on, and I believe we will not see the result soon. Generally speaking, GNOME attracts many companies at present, but the development efficiency and quality of KDE/Qt is higher than that of GNOME, and it will be in a dominant position in a certain period of time if it takes the first step in the Office/ embedded environment.

So for users, how to make a choice in Qt/GTK? Generally speaking, if users use Clippers, which requires high stability and robustness of the library, and wants cross-platform development, then using Qt is a better choice, but it is worth noting that although Qt's Free Edition uses the GPL declaration, if you develop Qt software on Windows or commercial software on Unix, you still need to pay copyright fees to Trolltech.

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