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gtk 开发手册和参考文档。 包括gtk glib gdk等

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<pre class="PROGRAMLISTING">
&#13;static void
save_column_order(const vector&lt;GAptPkgTree::ColumnType&gt; &amp; columns)
{
  g_return_if_fail(columns.size() == 
                   static_cast&lt;guint&gt;(GAptPkgTree::ColumnTypeEnd));

  int position = 0;
  vector&lt;GAptPkgTree::ColumnType&gt;::const_iterator i = columns.begin();
  while (i != columns.end())
    {
      gchar key[256];
      g_snprintf(key, 255, "/gnome-apt/ColumnOrder/%s", column_to_string(*i));
      gchar val[30];
      g_snprintf(val, 29, "%d", position);
      gnome_config_set_string(key, val);
      
      ++position;
      ++i;
    }

  gnome_config_sync();
}&#13;
</pre>
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          <p>
            When writing this code, the decision was made to store
            enumeration values as strings rather than integers. The
            <tt class="FUNCTION">column_to_string()</tt> and <tt
            class="FUNCTION">string_to_column()</tt> functions use
            a simple array of column names indexed by the
            enumeration values to convert back and forth. There are
            two reasons to do this: it will not break when the
            enumeration is altered in future versions of the
            program, and it keeps the configuration file
            human-editable.
          </p>
          <p>
            You may also notice that the column positions are
            stored with <tt class="FUNCTION">
            gnome_config_set_string()</tt> instead of <tt class= 
            "FUNCTION">gnome_config_set_int()</tt>. This is because
            <tt class="FUNCTION">gnome_config_iterator_next()</tt>
            returns a string representation of the stored
            information, as found in the file. Most likely, <tt
            class="FUNCTION">gnome_config_set_int()</tt> stores
            integers as strings <tt class="FUNCTION">atoi()</tt>
            would understand (in fact it does), but it is
            technically not guaranteed by the API. If the code used
            <tt class="FUNCTION">gnome_config_set_int()</tt>, it
            would have to obtain only the key from <tt class= 
            "FUNCTION">gnome_config_iterator_next()</tt> and then
            call <tt class="FUNCTION">gnome_config_get_int()</tt>
            to obtain the integer value. Using <tt class=
            "FUNCTION">atoi()</tt> on the string value would make
            unwarranted assumptions about <tt class="APPLICATION">
            gnome-config</tt>'s implementation.
          </p>
        </div>
        <div class="SECT3">
          <h3 class="SECT3">
            <a name="Z84">Section Iterators</a>
          </h3>
          <p>
            <tt class="FUNCTION">
            gnome_config_init_iterator_sections()</tt> allows you
            to iterate over the sections in a file, rather than
            over the keys in a section. When iterating over
            sections, <tt class="FUNCTION">
            gnome_config_iterator_next()</tt> ignores its <span
            class="STRUCTNAME">value</span> argument and places the
            section name in the <span class="STRUCTNAME">key</span>
            argument.
          </p>
          <div class="FIGURE">
            <a name="STARTUP-GNOMECONFIGITERATORS"></a>
            <div class="FUNCSYNOPSIS">
              <a name="STARTUP-GNOMECONFIGITERATORS.SYNOPSIS"></a>
              <table border="0" bgcolor="#E0E0E0" width="100%">
                <tr>
                  <td>
<pre class="FUNCSYNOPSISINFO">
#include &lt;libgnome/gnome-config.h&gt;
</pre>
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              <p>
                <code><code class="FUNCDEF">void* <tt class= 
                "FUNCTION">
                gnome_config_init_iterator</tt></code>(const gchar*
                <tt class="PARAMETER"><i>path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void* <tt class= 
                "FUNCTION">
                gnome_config_private_init_iterator</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void* <tt class= 
                "FUNCTION">
                gnome_config_init_iterator_sections</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void* <tt class= 
                "FUNCTION">
                gnome_config_private_init_iterator_sections</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void* <tt class= 
                "FUNCTION">
                gnome_config_iterator_next</tt></code>(void* <tt
                class="PARAMETER"><i>iterator_handle</i></tt>,
                gchar** <tt class="PARAMETER"><i>key</i></tt>,
                gchar** <tt class="PARAMETER"><i>
                value</i></tt>);</code>
              </p>
            </div>
            <p>
              <b>Figure 6. Configuration file iterators</b>
            </p>
          </div>
        </div>
        <div class="SECT3">
          <h3 class="SECT3">
            <a name="Z85">Other Config File Operations</a>
          </h3>
          <p>
            <a href="z79.html#STARTUP-GNOMECONFIGMISC">Figure 7</a>
            lists some additional operations available for
            manipulating config files. The most important of these
            have already been mentioned in passing. <tt class= 
            "FUNCTION">gnome_config_sync()</tt> writes the
            configuration file to disk, and <tt class="FUNCTION">
            gnome_config_push_prefix()</tt> allows you to shorten
            the path passed to the other <tt class="APPLICATION">
            gnome-config</tt> functions. There are also boolean
            tests, to ask <tt class="APPLICATION">gnome-config</tt>
            whether a given section exists.
          </p>
          <p>
            Two new operations are introduced: to <i class= 
            "FIRSTTERM">drop</i> a file or section means to forget
            any information about it stored in memory, including
            cached values loaded from the file and values not yet
            saved to the file with <tt class="FUNCTION">
            gnome_config_sync()</tt>. To <i class="FIRSTTERM">
            clean</i> a file, section, or key means to unset its
            value(s), so the file, section, or key will not exist
            once <tt class="FUNCTION">gnome_config_sync()</tt> is
            called.
          </p>
          <p>
            <tt class="FUNCTION">gnome_config_sync()</tt>
            automatically calls <tt class="FUNCTION">
            gnome_config_drop_all()</tt> to free all <tt class= 
            "APPLICATION">gnome-config</tt> resources, since the
            information is safely stored on disk.
          </p>
          <p>
            Functions are also provided to get the "real"
            (filesystem) path of a configuration file from a <tt
            class="APPLICATION">gnome-config</tt> path. These are
            unlikely to be useful in application code.
          </p>
          <div class="FIGURE">
            <a name="STARTUP-GNOMECONFIGMISC"></a>
            <div class="FUNCSYNOPSIS">
              <a name="STARTUP-GNOMECONFIGMISC.SYNOPSIS"></a>
              <table border="0" bgcolor="#E0E0E0" width="100%">
                <tr>
                  <td>
<pre class="FUNCSYNOPSISINFO">
#include &lt;libgnome/gnome-config.h&gt;
</pre>
                  </td>
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              <p>
                <code><code class="FUNCDEF">gboolean <tt class= 
                "FUNCTION">
                gnome_config_has_section</tt></code>(const gchar*
                <tt class="PARAMETER"><i>path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">gboolean <tt class= 
                "FUNCTION">
                gnome_config_private_has_section</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_drop_all</tt></code>(void);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_sync</tt></code>(void);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">gnome_config_sync_file</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_private_sync_file</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">gnome_config_drop_file</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_private_drop_file</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_clean_file</tt></code>(const gchar*
                <tt class="PARAMETER"><i>path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_private_clean_file</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_clean_section</tt></code>(const gchar*
                <tt class="PARAMETER"><i>path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_private_clean_section</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">gnome_config_clean_key</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_private_clean_key</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">gchar* <tt class= 
                "FUNCTION">
                gnome_config_get_real_path</tt></code>(const gchar*
                <tt class="PARAMETER"><i>path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">gchar* <tt class= 
                "FUNCTION">
                gnome_config_private_get_real_path</tt></code>(const
                gchar* <tt class="PARAMETER"><i>
                path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_push_prefix</tt></code>(const gchar*
                <tt class="PARAMETER"><i>path</i></tt>);</code>
              </p>
              <p>
                <code><code class="FUNCDEF">void <tt class=
                "FUNCTION">
                gnome_config_pop_prefix</tt></code>(void);</code>
              </p>
            </div>
            <p>
              <b>Figure 7. Miscellaneous configuration file
              functions</b>
            </p>
          </div>
        </div>
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