标题栏
我们的应用程序已经用了GtkHeaderBar，但至今它仍然只在顶端显示一个‘正常’的window titlebar。这有点多余，我们现在要用header bar 来替代titlebar。为了达到目的，我们将header bar移到窗口的直接子成员中，并把它设为titlebar。
<?xml version="1.0" encoding="UTF-8"?>
<interface>
<!-- interface-requires gtk+ 3.8 -->
<template class="ExampleAppWindow" parent="GtkApplicationWindow">
<property name="title" translatable="yes">Example Application</property>
<property name="default-width">600</property>
<property name="default-height">400</property>
<child type="titlebar">
<object class="GtkHeaderBar" id="header">
<property name="visible">True</property>
<property name="show-close-button">True</property>
<child>
<object class="GtkLabel" id="lines_label">
<property name="visible">False</property>
<property name="label" translatable="yes">Lines:</property>
</object>
<packing>
<property name="pack-type">start</property>
</packing>
</child>
<child>
<object class="GtkLabel" id="lines">
<property name="visible">False</property>
</object>
<packing>
<property name="pack-type">start</property>
</packing>
</child>
<child type="title">
<object class="GtkStackSwitcher" id="tabs">
<property name="visible">True</property>
<property name="margin">6</property>
<property name="stack">stack</property>
</object>
</child>
<child>
<object class="GtkToggleButton" id="search">
<property name="visible">True</property>
<property name="sensitive">False</property>
<style>
<class name="image-button"/>
</style>
<child>
<object class="GtkImage" id="search-icon">
<property name="visible">True</property>
<property name="icon-name">edit-find-symbolic</property>
<property name="icon-size">1</property>
</object>
</child>
</object>
<packing>
<property name="pack-type">end</property>
</packing>
</child>
<child>
<object class="GtkMenuButton" id="gears">
<property name="visible">True</property>
<property name="direction">none</property>
<property name="use-popover">True</property>
<style>
<class name="image-button"/>
</style>
</object>
<packing>
<property name="pack-type">end</property>
</packing>
</child>
</object>
</child>
<child>
<object class="GtkBox" id="content_box">
<property name="visible">True</property>
<property name="orientation">vertical</property>
<child>
<object class="GtkSearchBar" id="searchbar">
<property name="visible">True</property>
<child>
<object class="GtkSearchEntry" id="searchentry">
<signal name="search-changed" handler="search_text_changed"/>
<property name="visible">True</property>
</object>
</child>
</object>
</child>
<child>
<object class="GtkBox" id="hbox">
<property name="visible">True</property>
<child>
<object class="GtkRevealer" id="sidebar">
<property name="visible">True</property>
<property name="transition-type">slide-right</property>
<child>
<object class="GtkScrolledWindow" id="sidebar-sw">
<property name="visible">True</property>
<property name="hscrollbar-policy">never</property>
<property name="vscrollbar-policy">automatic</property>
<child>
<object class="GtkListBox" id="words">
<property name="visible">True</property>
<property name="selection-mode">none</property>
</object>
</child>
</object>
</child>
</object>
</child>
<child>
<object class="GtkStack" id="stack">
<signal name="notify::visible-child" handler="visible_child_changed"/>
<property name="visible">True</property>
</object>
</child>
</object>
</child>
</object>
</child>
</template>
</interface>
使用header bar的一个额外的好处是我们免费得到了一个回退项。如果这回退应用了，我们的应用程序将如下显示。
如果我们为窗口设定了图标，那么菜单按钮就是设定好的图标，而不是你现在看到的样子。