Bootstrap 4 超小列宽度 100% 不工作

Boostrap 4 extra small col width 100% not working

我用 Bootstrap 4 开发了一个静态 HTML 页面,使用 col 等同于大屏幕,但在 Extra small 屏幕上,col 没有得到 100% width。我忘记了什么?

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" />
<div class="container">
     <div class="form-row">
        <!-- Grid column -->
        <div class="col col-6">
            <!-- Material input -->
            <div class="md-form">
                <input type="text" class="form-control" placeholder="City">
            </div>
        </div>
        <!-- Grid column -->

        <!-- Grid column -->
        <div class="col">
            <!-- Material input -->
            <div class="md-form">
                <input type="text" class="form-control" placeholder="State">
            </div>
        </div>
        <!-- Grid column -->

        <!-- Grid column -->
        <div class="col">
            <!-- Material input -->
            <div class="md-form">
                <input type="text" class="form-control" placeholder="Zip">
            </div>
        </div>
        <!-- Grid column -->
    </div>
    </div>

Extra small col width 100% not working

列不是 100% 宽度,因为 col 是最小 xs 屏幕尺寸的 auto-layout column,因此列的宽度将继续缩小,并且永远不会堆叠垂直.

只需使用col-sm...

https://www.codeply.com/go/xb7WffaSmS

<div class="container">
    <div class="form-row">
        <!-- Grid column -->
        <div class="col-sm-6">
            <!-- Material input -->
            <div class="md-form">
                <input type="text" class="form-control" placeholder="City">
            </div>
        </div>
        <!-- Grid column -->

        <!-- Grid column -->
        <div class="col-sm">
            <!-- Material input -->
            <div class="md-form">
                <input type="text" class="form-control" placeholder="State">
            </div>
        </div>
        <!-- Grid column -->

        <!-- Grid column -->
        <div class="col-sm">
            <!-- Material input -->
            <div class="md-form">
                <input type="text" class="form-control" placeholder="Zip">
            </div>
        </div>
        <!-- Grid column -->
    </div>
</div>

另请注意,-xs 中缀已在 Bootstrap 中删除 4. 现在最小的 类 很简单 col, col-6, col-12, 等等...