在linux平台上的开发工具可说是百花齐放，可也同时造成各自为政割据一方的痛苦。图形界面开发更是如此，常用的就有gtk+, qt, wxWidgets, Tk, etc.且其中没有哪种能占据统治地位，成为事实上的标准。这对程序员来说是个很大的负担，毕竟全部精通是不可能的。
1 gtk+:
基于LGPL协议，属于GNU所有，没有版权问题，常用于商业软件开发和嵌入式系统的开发。提供C语言的接口，其对应的C++语言包装为gtkmm
gtk+ example:
helloword.c
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#include <gtk/gtk.h>
/* This is a callback function. The data arguments are ignored
* in this example. More on callbacks below. */
static void hello( GtkWidget *widget,
gpointer data )
{
g_print ("Hello World\n");
}
static gboolean delete_event( GtkWidget *widget,
GdkEvent *event,
gpointer data )
{
/* If you return FALSE in the "delete_event" signal handler,
* GTK will emit the "destroy" signal. Returning TRUE means
* you don't want the window to be destroyed.
* This is useful for popping up 'are you sure you want to quit?'
* type dialogs. */
g_print ("delete event occurred\n");
/* Change TRUE to FALSE and the main window will be destroyed with
* a "delete_event". */
return TRUE;
}
/* Another callback */
static void destroy( GtkWidget *widget,
gpointer data )
{
gtk_main_quit ();
}
int main( int argc,
char *argv[] )
{
/* GtkWidget is the storage type for widgets */
GtkWidget *window;
GtkWidget *button;
/* This is called in all GTK applications. Arguments are parsed
* from the command line and are returned to the application. */
gtk_init (&argc, &argv);
/* create a new window */
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
/* When the window is given the "delete_event" signal (this is given
* by the window manager, usually by the "close" option, or on the
* titlebar), we ask it to call the delete_event () function
* as defined above. The data passed to the callback
* function is NULL and is ignored in the callback function. */
g_signal_connect (G_OBJECT (window), "delete_event",
G_CALLBACK (delete_event), NULL);
/* Here we connect the "destroy" event to a signal handler.
* This event occurs when we call gtk_widget_destroy() on the window,
* or if we return FALSE in the "delete_event" callback. */
g_signal_connect (G_OBJECT (window), "destroy",
G_CALLBACK (destroy), NULL);
/* Sets the border width of the window. */
gtk_container_set_border_width (GTK_CONTAINER (window), 10);
/* Creates a new button with the label "Hello World". */
button = gtk_button_new_with_label ("Hello World");
/* When the button receives the "clicked" signal, it will call the
* function hello() passing it NULL as its argument. The hello()
* function is defined above. */
g_signal_connect (G_OBJECT (button), "clicked",
G_CALLBACK (hello), NULL);
/* This will cause the window to be destroyed by calling
* gtk_widget_destroy(window) when "clicked". Again, the destroy
* signal could come from here, or the window manager. */
g_signal_connect_swapped (G_OBJECT (button), "clicked",
G_CALLBACK (gtk_widget_destroy),
G_OBJECT (window));
/* This packs the button into the window (a gtk container). */
gtk_container_add (GTK_CONTAINER (window), button);
/* The final step is to display this newly created widget. */
gtk_widget_show (button);
/* and the window */
gtk_widget_show (window);
/* All GTK applications must have a gtk_main(). Control ends here
* and waits for an event to occur (like a key press or
* mouse event). */
gtk_main ();
return 0;
}
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编译：
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gcc `pkg-config --cflags --libs gtk+-2.0` helloworld.c -o helloworld
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gtkmm example:
helloworld.h
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#ifndef GTKMM_EXAMPLE_HELLOWORLD_H
#define GTKMM_EXAMPLE_HELLOWORLD_H
#include <gtkmm/button.h>
#include <gtkmm/window.h>
class HelloWorld : public Gtk::Window
{
public:
HelloWorld();
virtual ~HelloWorld();
protected:
//Signal handlers:
virtual void on_button_clicked();
//Member widgets:
Gtk::Button m_button;
};
#endif // GTKMM_EXAMPLE_HELLOWORLD_H
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helloworld.cc
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#include "helloworld.h"
#include <iostream>
HelloWorld::HelloWorld()
: m_button("Hello World") // creates a new button with label "Hello World".
{
// Sets the border width of the window.
set_border_width(10);
// When the button receives the "clicked" signal, it will call the
// on_button_clicked() method defined below.
m_button.signal_clicked().connect(sigc::mem_fun(*this,
&HelloWorld::on_button_clicked));
// This packs the button into the Window (a container).
add(m_button);
// The final step is to display this newly created widget...
m_button.show();
}
HelloWorld::~HelloWorld()
{
}
void HelloWorld::on_button_clicked()
{
std::cout << "Hello World" << std::endl;
}
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main.cc
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#include <gtkmm/main.h>
#include "helloworld.h"
int main (int argc, char *argv[])
{
Gtk::Main kit(argc, argv);
HelloWorld helloworld;
//Shows the window and returns when it is closed.
Gtk::Main::run(helloworld);
return 0;
}
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编译：
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$ g++ `pkg-config --cflags --libs gtkmm-2.4` *cc *.h -o helloworld
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2 qt
example:
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#include <QApplication>
#include <QLabel>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QLabel *label = new QLabel("Hello Qt!");
label->show();
return app.exec();
}
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编译：
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$ qmake -project #generate project: helloworld.pro
$ qmake helloworld.pro
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3 wxWidgets
example:
hworld.cpp
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#include "wx/wx.h"
// 定义应用程序类
class MyApp : public wxApp
{
public:
// 这个函数将会在程序启动的时候被调用
virtual bool OnInit();
};
// 定义主窗口类
class MyFrame : public wxFrame
{
public:
// 主窗口类的构造函数
MyFrame(const wxString& title);
// 事件处理函数
void OnQuit(wxCommandEvent& event);
void OnAbout(wxCommandEvent& event);
private:
// 声明事件表
DECLARE_EVENT_TABLE()
};
// 有了这一行就可以使用 MyApp& wxGetApp()了
DECLARE_APP(MyApp)
// 告诉wxWidgets主应用程序是哪个类
IMPLEMENT_APP(MyApp)
// 初始化程序
bool MyApp::OnInit()
{
// 创建主窗口
MyFrame *frame = new MyFrame(wxT("Minimal wxWidgets App"));
// 显示主窗口
frame->Show(true);
// 开始事件处理循环
return true;
}
// MyFrame类的事件表
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(wxID_ABOUT, MyFrame::OnAbout)
EVT_MENU(wxID_EXIT, MyFrame::OnQuit)
END_EVENT_TABLE()
void MyFrame::OnAbout(wxCommandEvent& event)
{
wxString msg;
msg.Printf(wxT("Hello and welcome to %s"),wxVERSION_STRING);
wxMessageBox(msg, wxT("About Minimal"),wxOK | wxICON_INFORMATION, this);
}
void MyFrame::OnQuit(wxCommandEvent& event)
{
// 释放主窗口
Close();
}
//#include "mondrian.xpm"
MyFrame::MyFrame(const wxString& title): wxFrame(NULL, wxID_ANY, title)
{
// 设置窗口图标
// SetIcon(wxIcon(mondrian_xpm));
// 创建菜单条
wxMenu *fileMenu = new wxMenu;
// 添加“关于”菜单项
wxMenu *helpMenu = new wxMenu;
helpMenu->Append(wxID_ABOUT, wxT("&About...\tF1"),wxT("Show about dialog"));
fileMenu->Append(wxID_EXIT, wxT("E&xit\tAlt-X"),wxT("Quit this program"));
// 将菜单项添加到菜单条中
wxMenuBar *menuBar = new wxMenuBar();
menuBar->Append(fileMenu, wxT("&File"));
menuBar->Append(helpMenu, wxT("&Help"));
// ...然后将菜单条放置在主窗口上
SetMenuBar(menuBar);
// 创建一个状态条来让一切更有趣些。
CreateStatusBar(2);
SetStatusText(wxT("Welcome to wxWidgets!"));
}
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编译：
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$ g++ hworld.cpp `wx-config --libs` `wx-config --cxxflags` -o hworld
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(thinkfree) |
