但是如果仔细查看mantisGraph的配置会发现实际上可以配置使用的字体文件是什么字体，目前支持配置Sans-serif、Serif、Monospace等字体。修改该配置后，却发现不生效。进一步仔细研究mantisGraph的代码，发现了以下代码（于文件core/graph_api.php中）：

function graph_get_font() {
    $t_font = plugin_config_get( ‘font’， ” );

    if ( plugin_config_get( ‘eczlibrary’ ) == ON ) {
        $ttf_dir = ”;
        $t_font = ”;

        $t_font_map = array(
            ‘arial’ => ‘arial.ttf’，
            ‘verdana’ => ‘verdana.ttf’，
            ‘trebuchet’ => ‘trebuc.ttf’，
            ‘verasans’ => ‘Vera.ttf’，
            ‘times’ => ‘times.ttf’，
            ‘georgia’ => ‘georgia.ttf’，
            ‘veraserif’ => ‘VeraSe.ttf’，
            ‘courier’ => ‘cour.ttf’，
            ‘veramono’ => ‘VeraMono.ttf’，
        );

        if( isset( $t_font_map[$t_font] ) ) {
            $t_font = $t_font_map[$t_font];
        } else {
            $t_font = ‘arial.ttf’;
        }

 其中$t_font = ”;这行代码是的配置信息在这儿被重置，于是后的将会执行$t_font = ‘arial.ttf’;这行代码。所以无论如何修改配置都不生效。

为了使得配置能生效，则注释掉$t_font = ”;这行。同时新增一个t_font_map的数据项， ’wqy-zenhei’ => ‘wqy-zenhei.ttf’，接下来修改配置界面使得可以在界面上看到wqy-zenhei的配置。打开文件pages/config.php。变动如下：

diff -uNr mantisbt-1.2.2/plugins/MantisGraph/pages/config.php mantisbt-1.2.2.new/plugins/MantisGraph/pages/config.php
— mantisbt-1.2.2/plugins/MantisGraph/pages/config.php      2010-07-30 00:46:31.000000000 +0800
+++ mantisbt-1.2.2.new/plugins/MantisGraph/pages/config.php        2010-08-11 11:35:55.000000000 +0800
@@ -22，6 +22，7 @@
 print_manage_menu( );

 $t_current_font_selected = array(
+       ‘wqy-zenhei’ => false，
        ‘arial’ => false，
        ‘verdana’ => false，
        ‘trebuchet’ => false，
@@ -118，6 +119，7 @@
        </td>
        <td style=”vertical-align: top”>
                Sans-serif:<br />
+               <label><input type=”radio” name=”font” value=”wqy-zenhei”<?php echo print_font_checked( ‘wqy-zenhei’ )?>/>WenQuanYi ZenHei</label><br />
                <label><input type=”radio” name=”font” value=”arial”<?php echo print_font_checked( ‘arial’ )?>/>Arial</label><br />
                <label><input type=”radio” name=”font” value=”verdana”<?php echo print_font_checked( ‘verdana’ )?>/>Verdana</label><br />
                <label><input type=”radio” name=”font” value=”trebuchet”<?php echo print_font_checked( ‘trebuchet’ )?>/>Trebuchet</label><br />

打开文件pages/config_edit.php，变动如下：

diff -uNr mantisbt-1.2.2/plugins/MantisGraph/pages/config_edit.php mantisbt-1.2.2.new/plugins/MantisGraph/pages/config_edit.php
— mantisbt-1.2.2/plugins/MantisGraph/pages/config_edit.php 2010-07-30 00:46:31.000000000 +0800
+++ mantisbt-1.2.2.new/plugins/MantisGraph/pages/config_edit.php   2010-08-11 11:36:15.000000000 +0800
@@ -46，6 +46，7 @@

 if ( plugin_config_get( ‘font’ ) != $f_font ) {
        switch ( $f_font ) {
+               case ‘wqy-zenhei’:
                case ‘arial’:
                case ‘verdana’:
                case ‘trebuchet’:

这样可以在mantis的配置界面中看到相应的配置了。当然好是进一步修改文件实现搜索字体文件的功能，将搜索到的字体文件提供给用户选择。