自定义角度指令未在离子导航栏中显示(Custom AngularJS directive not showing in Ionic nav bar)

 我有离子导航栏，里面有两个离子导航按钮和一个自定义角度指令（header-logo-dropdown）。 当我进行路由或更改浏览器窗口大小时，自定义指令有时不显示，所以我有两个问题： 
 
 1）在离子导航栏中包含自定义HTML和指令的正确方法是什么？ 
 
 2）我写的代码有什么问题？ 
 
<ion-pane ion-side-menu-content drag-content="false">

    <ion-nav-bar show-when="(max-width:767px)" class="bar  bar-header  bar-light header-nav-container">
        <ion-nav-buttons side="left" id="button--menu">
            <button menu-toggle="left" class="button  button-icon  icon  ion-navicon-round" show-when="(max-width:767px)"></button>
        </ion-nav-buttons>

        <div class="title header-logo-container">
            <header-logo-dropdown></header-logo-dropdown>
        </div>

        <ion-nav-buttons side="right">
            <a class="button  bar-header__iconprofile" href="#/user"><i class="icon iconSilver profile item-silver"></i> </a>
        </ion-nav-buttons>

    </ion-nav-bar>

    <ion-view>
        <ion-nav-view animation="slide-left-right">
        </ion-nav-view>
    </ion-view>

</ion-pane>

I have ion-nav-bar and there are two ion-nav-buttons and one custom Angular directive inside (header-logo-dropdown). When I am doing routing or changing browser window size, the custom directive is not showing sometimes, so I have two questions about this:
 
1) What is the proper method to include custom HTML and directive in ion-nav-bar?
 
2) What is wrong with the code I've written?
 
<ion-pane ion-side-menu-content drag-content="false">

    <ion-nav-bar show-when="(max-width:767px)" class="bar  bar-header  bar-light header-nav-container">
        <ion-nav-buttons side="left" id="button--menu">
            <button menu-toggle="left" class="button  button-icon  icon  ion-navicon-round" show-when="(max-width:767px)"></button>
        </ion-nav-buttons>

        <div class="title header-logo-container">
            <header-logo-dropdown></header-logo-dropdown>
        </div>

        <ion-nav-buttons side="right">
            <a class="button  bar-header__iconprofile" href="#/user"><i class="icon iconSilver profile item-silver"></i> </a>
        </ion-nav-buttons>

    </ion-nav-bar>

    <ion-view>
        <ion-nav-view animation="slide-left-right">
        </ion-nav-view>
    </ion-view>

</ion-pane>

原文：https://stackoverflow.com/questions/37009511