Angular Material md-card-title-text的高度为0

Kiw*_*iwi 3 angularjs angular-material

我想弄清楚为什么我的md-card-title-text渲染不正确,我没有任何额外的CSS,只是默认的角度材料

我正在使用以下代码来显示它:

<md-card>
    <md-card-header>
        <md-card-avatar>
            <img class="md-user-avatar" src="https://material.angularjs.org/HEAD/img/100-2.jpeg" />
        </md-card-avatar>
        <md-card-header-text>
            <span class="md-title">User</span>
            <span class="md-subhead">subhead</span>
        </md-card-header-text>
    </md-card-header>
    <md-card-title>
        <md-card-title-text>
            <span class="md-headline">In-card mixed actions</span>
            <span class="md-subhead">Reversed</span>
        </md-card-title-text>
    </md-card-title>
    <md-card-content>
        <p>
            The titles of Washed Out's breakthrough song and the first single from Paracosm share the two most important words in Ernest Greene's musical language: feel it. It's a simple request, as well...
        </p>
    </md-card-content>
    <md-card-actions layout="row" layout-align="start center">
        <md-button>Action 1</md-button>
        <md-button>Action 2</md-button>
        <md-card-icon-actions>
            <md-button class="md-icon-button" aria-label="toggle">
                <md-icon md-svg-icon="md-toggle-arrow"></md-icon>
            </md-button>
        </md-card-icon-actions>
    </md-card-actions>    
</md-card>
Run Code Online (Sandbox Code Playgroud)

这是一个显示问题的屏幕截图:

截图

小智 5

我有同样的错误,无法在Codepen或其他任何地方重现它.经过一段时间的尝试,我发现我忘了添加<!DOCTYPE html>到html文件,这解决了问题.

最诚挚的问候,
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