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<html xmlns:cf="http://docbook.sourceforge.net/xmlns/chunkfast/1.0"><head><meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"><title>Keyed Data Lists</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.0"><link rel="start" href="index.html" title="GLib Reference Manual"><link rel="up" href="glib-data-types.html" title="GLib Data Types"><link rel="prev" href="glib-Quarks.html" title="Quarks"><link rel="next" href="glib-Datasets.html" title="Datasets"><meta name="generator" content="GTK-Doc V1.4 (XML mode)"><link rel="stylesheet" href="style.css" type="text/css"><link rel="chapter" href="glib.html" title="GLib Overview"><link rel="chapter" href="glib-fundamentals.html" title="GLib Fundamentals"><link rel="chapter" href="glib-core.html" title="GLib Core Application Support"><link rel="chapter" href="glib-utilities.html" title="GLib Utilities"><link rel="chapter" href="glib-data-types.html" title="GLib Data Types"><link rel="chapter" href="tools.html" title="GLib Tools"><link rel="index" href="ix01.html" title="Index"><link rel="index" href="ix02.html" title="Index of deprecated symbols"><link rel="index" href="ix03.html" title="Index of new symbols in 2.2"><link rel="index" href="ix04.html" title="Index of new symbols in 2.4"><link rel="index" href="ix05.html" title="Index of new symbols in 2.6"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><table class="navigation" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"><td><a accesskey="p" href="glib-Quarks.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td><td><a accesskey="u" href="glib-data-types.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td><td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td><th width="100%" align="center">GLib Reference Manual</th><td><a accesskey="n" href="glib-Datasets.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td></tr></table><div class="refentry" lang="en"><a name="glib-Keyed-Data-Lists"></a><div class="titlepage"></div><div class="refnamediv"><table width="100%"><tr><td valign="top"><h2><span class="refentrytitle">Keyed Data Lists</span></h2><p>Keyed Data Lists — lists of data elements which are accessible by a string or <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> identifier.</p></td><td valign="top" align="right"></td></tr></table></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">#include <glib.h> <a href="glib-Keyed-Data-Lists.html#GData">GData</a>;void <a href="glib-Keyed-Data-Lists.html#g-datalist-init">g_datalist_init</a> (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist);#define <a href="glib-Keyed-Data-Lists.html#g-datalist-id-set-data">g_datalist_id_set_data</a> (dl, q, d)void <a href="glib-Keyed-Data-Lists.html#g-datalist-id-set-data-full">g_datalist_id_set_data_full</a> (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist, <a href="glib-Quarks.html#GQuark">GQuark</a> key_id, <a href="glib-Basic-Types.html#gpointer">gpointer</a> data, <a href="glib-Datasets.html#GDestroyNotify">GDestroyNotify</a> destroy_func);<a href="glib-Basic-Types.html#gpointer">gpointer</a> <a href="glib-Keyed-Data-Lists.html#g-datalist-id-get-data">g_datalist_id_get_data</a> (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist, <a href="glib-Quarks.html#GQuark">GQuark</a> key_id);#define <a href="glib-Keyed-Data-Lists.html#g-datalist-id-remove-data">g_datalist_id_remove_data</a> (dl, q)<a href="glib-Basic-Types.html#gpointer">gpointer</a> <a href="glib-Keyed-Data-Lists.html#g-datalist-id-remove-no-notify">g_datalist_id_remove_no_notify</a> (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist, <a href="glib-Quarks.html#GQuark">GQuark</a> key_id);#define <a href="glib-Keyed-Data-Lists.html#g-datalist-set-data">g_datalist_set_data</a> (dl, k, d)#define <a href="glib-Keyed-Data-Lists.html#g-datalist-set-data-full">g_datalist_set_data_full</a> (dl, k, d, f)#define <a href="glib-Keyed-Data-Lists.html#g-datalist-get-data">g_datalist_get_data</a> (dl, k)#define <a href="glib-Keyed-Data-Lists.html#g-datalist-remove-data">g_datalist_remove_data</a> (dl, k)#define <a href="glib-Keyed-Data-Lists.html#g-datalist-remove-no-notify">g_datalist_remove_no_notify</a> (dl, k)void <a href="glib-Keyed-Data-Lists.html#g-datalist-foreach">g_datalist_foreach</a> (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist, <a href="glib-Datasets.html#GDataForeachFunc">GDataForeachFunc</a> func, <a href="glib-Basic-Types.html#gpointer">gpointer</a> user_data);void <a href="glib-Keyed-Data-Lists.html#g-datalist-clear">g_datalist_clear</a> (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist);</pre></div><div class="refsect1" lang="en"><a name="id3191960"></a><h2>Description</h2><p>Keyed data lists provide lists of arbitrary data elements which can be accessedeither with a string or with a <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> corresponding to thestring.</p><p>The <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> methods are quicker, since the strings have to be converted to<span class="type">GQuarks</span> anyway.</p><p>Data lists are used for associating arbitrary data with<span class="type">GObjects</span>, using <ahref="../gobject/gobject-The-Base-Object-Type.html#g-object-set-data"><code class="function">g_object_set_data()</code></a> and related functions.</p><p>To create a datalist, use <a href="glib-Keyed-Data-Lists.html#g-datalist-init"><code class="function">g_datalist_init()</code></a>.</p><p>To add data elements to a datalist use <a href="glib-Keyed-Data-Lists.html#g-datalist-id-set-data"><code class="function">g_datalist_id_set_data()</code></a>,<a href="glib-Keyed-Data-Lists.html#g-datalist-id-set-data-full"><code class="function">g_datalist_id_set_data_full()</code></a>, <a href="glib-Keyed-Data-Lists.html#g-datalist-set-data"><code class="function">g_datalist_set_data()</code></a>and <a href="glib-Keyed-Data-Lists.html#g-datalist-set-data-full"><code class="function">g_datalist_set_data_full()</code></a>.</p><p>To get data elements from a datalist use <a href="glib-Keyed-Data-Lists.html#g-datalist-id-get-data"><code class="function">g_datalist_id_get_data()</code></a> and<a href="glib-Keyed-Data-Lists.html#g-datalist-get-data"><code class="function">g_datalist_get_data()</code></a>.</p><p>To iterate over all data elements in a datalist use <a href="glib-Keyed-Data-Lists.html#g-datalist-foreach"><code class="function">g_datalist_foreach()</code></a>.</p><p>To remove data elements from a datalist use <a href="glib-Keyed-Data-Lists.html#g-datalist-id-remove-data"><code class="function">g_datalist_id_remove_data()</code></a> and<a href="glib-Keyed-Data-Lists.html#g-datalist-remove-data"><code class="function">g_datalist_remove_data()</code></a>.</p><p>To remove all data elements from a datalist, use <a href="glib-Keyed-Data-Lists.html#g-datalist-clear"><code class="function">g_datalist_clear()</code></a>.</p></div><div class="refsect1" lang="en"><a name="id3192170"></a><h2>Details</h2><div class="refsect2" lang="en"><a name="id3192176"></a><h3><a name="GData"></a>GData</h3><a class="indexterm" name="id3192186"></a><pre class="programlisting">typedef struct _GData GData;</pre><p>The <a href="glib-Keyed-Data-Lists.html#GData"><span class="type">GData</span></a> struct is an opaque data structure to represent a<a href="glib-Keyed-Data-Lists.html" title="Keyed Data Lists">Keyed Data List</a>.It should only be accessed via the following functions.</p></div><hr><div class="refsect2" lang="en"><a name="id3192219"></a><h3><a name="g-datalist-init"></a>g_datalist_init ()</h3><a class="indexterm" name="id3192229"></a><pre class="programlisting">void g_datalist_init (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist);</pre><p>Resets the datalist to <code class="literal">NULL</code>.It does not free any memory or call any destroy functions.</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>datalist</code></em> :</span></td><td>a pointer to a pointer to a datalist.</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3192283"></a><h3><a name="g-datalist-id-set-data"></a>g_datalist_id_set_data()</h3><a class="indexterm" name="id3192294"></a><pre class="programlisting">#define g_datalist_id_set_data(dl, q, d)</pre><p>Sets the data corresponding to the given <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> id.Any previous data with the same key is removed, and itsdestroy function is called.</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>dl</code></em> :</span></td><td>a datalist.</td></tr><tr><td><span class="term"><em class="parameter"><code>q</code></em> :</span></td><td>the <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> to identify the data element.</td></tr><tr><td><span class="term"><em class="parameter"><code>d</code></em> :</span></td><td>the data element, or <code class="literal">NULL</code> to remove any previous elementcorresponding to <em class="parameter"><code>q</code></em>.</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3192386"></a><h3><a name="g-datalist-id-set-data-full"></a>g_datalist_id_set_data_full ()</h3><a class="indexterm" name="id3192397"></a><pre class="programlisting">void g_datalist_id_set_data_full (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist, <a href="glib-Quarks.html#GQuark">GQuark</a> key_id, <a href="glib-Basic-Types.html#gpointer">gpointer</a> data, <a href="glib-Datasets.html#GDestroyNotify">GDestroyNotify</a> destroy_func);</pre><p>Sets the data corresponding to the given <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> id, and the function tobe called when the element is removed from the datalist.Any previous data with the same key is removed, and itsdestroy function is called.</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>datalist</code></em> :</span></td><td>a datalist.</td></tr><tr><td><span class="term"><em class="parameter"><code>key_id</code></em> :</span></td><td>the <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> to identify the data element.</td></tr><tr><td><span class="term"><em class="parameter"><code>data</code></em> :</span></td><td>the data element or <code class="literal">NULL</code> to remove any previous elementcorresponding to <em class="parameter"><code>key_id</code></em>.</td></tr><tr><td><span class="term"><em class="parameter"><code>destroy_func</code></em> :</span></td><td>the function to call when the data element is removed. Thisfunction will be called with the data element and can be used to free anymemory allocated for it. If <em class="parameter"><code>data</code></em> is <code class="literal">NULL</code>, then <em class="parameter"><code>destroy_func</code></em> mustalso be <code class="literal">NULL</code>.</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3192567"></a><h3><a name="g-datalist-id-get-data"></a>g_datalist_id_get_data ()</h3><a class="indexterm" name="id3192578"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gpointer">gpointer</a> g_datalist_id_get_data (<a href="glib-Keyed-Data-Lists.html#GData">GData</a> **datalist, <a href="glib-Quarks.html#GQuark">GQuark</a> key_id);</pre><p>Retrieves the data element corresponding to <em class="parameter"><code>key_id</code></em>. </p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>datalist</code></em> :</span></td><td>a datalist.</td></tr><tr><td><span class="term"><em class="parameter"><code>key_id</code></em> :</span></td><td>the <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> identifying a data element.</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>the data element, or <code class="literal">NULL</code> if it is not found.</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3192678"></a><h3><a name="g-datalist-id-remove-data"></a>g_datalist_id_remove_data()</h3><a class="indexterm" name="id3192688"></a><pre class="programlisting">#define g_datalist_id_remove_data(dl, q)</pre><p>Removes an element, using its <a href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> identifier.</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><em class="parameter"><code>dl</code></em> :</span></td><td>a datalist.</td></tr><tr>⌨️ 快捷键说明
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