GTK+图形化应用程序开发学习笔记（二）—Glib库

本是古典何须时尚 2022-03-26 13:40 244阅读 0赞

在学习GTK+之前我们需要先学习一下 glib的有关知识。因为我们将会在以后的学习中遇到这些知识。由于本笔记不是专门介绍glib的，所以下面的介绍不会太详细。

一、什么是glib库

glib库是linux平台下最常用的c语言函数库，它具有很好的可移植性和实用性。glib是gtk+库和gnome的基础。glib的各种实用程序具有一致的接口。glib为许多标准的、常用的C语言结构提供了相应的替代物。它的编码风格是半面向对象，标识符加了一个前缀“g”，这也是一种通行的命名约定。使glib库的程序都应该包含glib的头文件glib.h。如果程序已经包含了gtk .h则不需要再包含glib.h。

二、glib的类型定义

glib的类型定义不是使用C的标准类型，它自己有一套类型系统。它们比常用的C语言的类型更丰富，也更安全可靠。引进这套系统是为了多种原因。

以下是glib基本类型定义：

整数类型：gint8、guint8、gint16、guint16、gint32、guint32、gint64、guint64。其中gint8是8位的整数，guint8是8位的无符号整数，其他依此类推。这些整数类型能够保证大小。不是所有的平台都提供64位整型，如果一个平台有这些， glib会定义G\_HAVE\_GINT64。

整数类型gshort、glong、gint和short、long、int完全等价。

布尔类型gboolean：它可使代码更易读，因为普通C没有布尔类型。Gboolean可以取两个值：TRUE和FALSE。实际上FALSE定义为0，而TRUE定义为非零值。

字符型gchar和char完全一样，只是为了保持一致的命名。

浮点类型gfloat、gdouble和float、double完全等价。

指针gpointer对应于标准C的void \*，但是比void \*更方便。

指针gconst pointer对应于标准C的const void \*（注意，将const void \*定义为const gpointer是行不通的）。

三、glib的宏

glib除了定义一些在c程序中常见的宏外，还定义了一些用于类型转换的宏。如

GINT\_TO\_POINTER(p)

GPOINTER\_TO\_INT(p)

GUINT\_TO\_POINTER(p)

GPOINTER\_TO\_UINT(p)

这些宏允许在一个指针中存储一个整数，但在一个整数中存储一个指针是不行的。如果

要实现的话，必须在一个长整型中存储指针。

例如，我们想把一个int型整数转换为pointer型数，我们

四、内存管理

glib用自己的g\_变体包装了标准的malloc( )和free( )，即g\_malloc() 和g\_free( )。它们有以下几个小优点：

• g\_malloc()总是返回gpointer，而不是char \*，所以不必转换返回值。

•如果低层的malloc ( )失败，g\_malloc ( )将退出程序，所以不必检查返回值是否是NULL。

• g\_malloc() 对于分配0字节返回NULL。

• g\_free()忽略任何传递给它的NULL指针。

1．

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2．

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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> #include &lt;glib.h&gt; </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:12.1pt; background-color:transparent"> void g_free(gpointer mem); </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:10.95pt; background-color:transparent"> mem志向空间的指针 </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 无 </td> 
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五、出错处理函数

3．

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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> #include &lt;glib.h&gt; </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:12.1pt; background-color:transparent"> gchar *g_strerror(gint errnum); </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:10.95pt; background-color:transparent"> errnum&nbsp;&nbsp; 给定的错误代码 </td> 
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 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 返回值： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 一条对应于给定错误代码的错误字符串信息 </td> 
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g\_strerror返回一条对应于给定错误代码的错误字符串信息，例如“ no such process”等。

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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> #include &lt;glib.h&gt; </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:12.1pt; background-color:transparent"> void g_error(gchar *format,…); </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 无 </td> 
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g\_error 函数显示应用软件中的严重错误。它在错误信息前加上了"\*\* ERROR \*\*"，并结束程序的运行。只当可能发生导致程序退出的错误才使用这一函数.

5．

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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> #include &lt;glib.h&gt; </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:12.1pt; background-color:transparent"> void g_warning(gchar *format,…); </td> 
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 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 无 </td> 
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g\_warning当发生可恢复的错误而且程序能够继续运行时，函数g\_warning在错误信息前加上 " \*\* WARNING \*\* "，。GTK+用这一函数向程序设计人员显示已经成功处理了的错误。

六、与错误无关的显示消息函数

6．

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 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 返回值： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 无 </td> 
 </tr> 
 </tbody> 
</table>

g\_message函数显示与错误无关的消息。在传递的字符串前打印 "message:"

7．

<table style="margin:auto 6.75pt; border-collapse:collapse"> 
 <tbody> 
 <tr style="height:15.5pt"> 
 <td style="border:1pt solid windowtext; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 名称:： </td> 
 <td style="border-style:solid solid solid none; border-color:windowtext windowtext windowtext rgb(236,233,216); border-width:1pt 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> g_print </td> 
 </tr> 
 <tr style="height:14.75pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:14.75pt; background-color:transparent"> 功能： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:14.75pt; background-color:transparent"> 显示消息 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 头文件： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> #include &lt;glib.h&gt; </td> 
 </tr> 
 <tr style="height:12.1pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:12.1pt; background-color:transparent"> 函数原形： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:12.1pt; background-color:transparent"> void g_print(gchar *format,…); </td> 
 </tr> 
 <tr style="height:10.95pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:10.95pt; background-color:transparent"> 参数： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:10.95pt; background-color:transparent"> format&nbsp;&nbsp; 信息 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 返回值： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 无 </td> 
 </tr> 
 </tbody> 
</table>

g\_print函数通常用于调试。你可以在开发过程中使用g\_print函数，并在实际使用时撤消它的功能。

下面我们用上一节的程序验证着这些函数。

<table style="border:medium none; border-collapse:collapse"> 
 <tbody> 
 <tr style=""> 
 <td style="border:1pt solid windowtext; padding:0cm 5.4pt; width:426.1pt; background-color:transparent"> #include &lt;gtk/gtk.h&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; int main(int argc, char* argv[]) { GtkWidget *window; &nbsp; &nbsp;&nbsp;gtk_init(&amp;argc,&amp;argv); &nbsp; &nbsp;&nbsp;window = gtk_window_new(GTK_WINDOW_TOPLEVEL); gtk_widget_show(window); g_print(“hello world”); g_warning(“hello world”); g_message(“hello world”); //g_error(“hello world”); &nbsp; &nbsp;&nbsp;gtk_main(); &nbsp; &nbsp;&nbsp;return FALSE; } </td> 
 </tr> 
 </tbody> 
</table>

程序的运行结果为：

\#gcc –o base base.c \`pkg-config –cflags –libs gtk+-2.0\`

\#./base

hello world

\*\* (base:8850) :  WARNIG \*\* : hello world

\*\* Message: hello world

七、Timeout 函数

Timeout函数会隔一定时间(毫秒)就自动地调用一次。下面的函数用于添加一个Timeout函数。定时函数类似于回调函数（我们将在下节介绍）。

8．

<table style="margin:auto 6.75pt; border-collapse:collapse"> 
 <tbody> 
 <tr style="height:15.5pt"> 
 <td style="border:1pt solid windowtext; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 名称:： </td> 
 <td style="border-style:solid solid solid none; border-color:windowtext windowtext windowtext rgb(236,233,216); border-width:1pt 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> g_timeout_add </td> 
 </tr> 
 <tr style="height:14.75pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:14.75pt; background-color:transparent"> 功能： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:14.75pt; background-color:transparent"> 添加一个Timeout函数 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 头文件： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> #include &lt;glib.h&gt; </td> 
 </tr> 
 <tr style="height:12.1pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:12.1pt; background-color:transparent"> 函数原形： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:12.1pt; background-color:transparent"> gint gtk_timeout_add(guint32 interval,GtkFunction function,gpointer data); </td> 
 </tr> 
 <tr style="height:10.95pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:10.95pt; background-color:transparent"> 参数： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:10.95pt; background-color:transparent"> interval&nbsp;&nbsp;&nbsp; 调用定时函数的时间间隔 function&nbsp;&nbsp;&nbsp; 要调用的函数定时函数 data&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 传递给定时函数的参数 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 返回值： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 返回一个整形“标志“ </td> 
 </tr> 
 </tbody> 
</table>

可以用下面的函数停止调用定时函数：

9．

<table style="margin:auto 6.75pt; border-collapse:collapse"> 
 <tbody> 
 <tr style="height:15.5pt"> 
 <td style="border:1pt solid windowtext; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 名称:： </td> 
 <td style="border-style:solid solid solid none; border-color:windowtext windowtext windowtext rgb(236,233,216); border-width:1pt 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> g_timeout_remove </td> 
 </tr> 
 <tr style="height:14.75pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:14.75pt; background-color:transparent"> 功能： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:14.75pt; background-color:transparent"> 停止调用定时函数 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 头文件： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> #include &lt;glib.h&gt; </td> 
 </tr> 
 <tr style="height:12.1pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:12.1pt; background-color:transparent"> 函数原形： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:12.1pt; background-color:transparent"> void gtk_timeout_remove(gint tag); </td> 
 </tr> 
 <tr style="height:10.95pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:10.95pt; background-color:transparent"> 参数： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:10.95pt; background-color:transparent"> tag&nbsp;&nbsp;&nbsp;&nbsp; g_timeout_add函数返回的标志 </td> 
 </tr> 
 <tr style="height:15.5pt"> 
 <td style="border-style:none solid solid; border-color:rgb(236,233,216) windowtext windowtext; border-width:medium 1pt 1pt; padding:0cm 5.4pt; width:96.05pt; height:15.5pt; background-color:transparent"> 返回值： </td> 
 <td style="border-style:none solid solid none; border-color:rgb(236,233,216) windowtext windowtext rgb(236,233,216); border-width:medium 1pt 1pt medium; padding:0cm 5.4pt; width:333.05pt; height:15.5pt; background-color:transparent"> 无 </td> 
 </tr> 
 </tbody> 
</table>

还可以让回调函数返回FA L S E或0来停止调用定时函数。也就是说，要想让函数继续调用，必须让它返回一个非0值或T R U E。

定期调用的回调函数声明应该是下面的形式：

gint timeout\_callback( gpointer data );

下面是程序例子：

<table style="border:medium none; width:426.1pt; border-collapse:collapse"> 
 <tbody> 
 <tr style=""> 
 <td style="border:1pt solid windowtext; padding:0cm 5.4pt; width:426.1pt; background-color:transparent"> #include &lt;gtk/gtk.h&gt; gint n=1; gint function(gpointer data); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; int main(int argc, char* argv[]) { GtkWidget *window; gpointer data; gint sign; &nbsp; &nbsp; &nbsp;&nbsp;gtk_init(&amp;argc,&amp;argv); &nbsp; &nbsp;&nbsp;window = gtk_window_new(GTK_WINDOW_TOPLEVEL); gtk_widget_show(window); sign=g_timeout_add(500,function,data); &nbsp; &nbsp;&nbsp;gtk_main(); &nbsp; &nbsp;&nbsp;return FALSE; } &nbsp; gint function(gpointer data) { g_print(“hello”); if(++n&gt;5) &nbsp;&nbsp;&nbsp; return 0; } &nbsp; </td> 
 </tr> 
 </tbody> 
</table>

程序每隔500毫秒输出一个hello.输出5个结束。