在Bootstrap 4中使用.align-self-*-start类在不同屏幕上从头开始对齐flex项目。
在不同屏幕上对齐弹性项目-
小萤幕
<div class="d-flex bg-info" style="height:200px"> <div class="p-2 border">Item 1</div> <div class="p-2 border">Item 2</div> <div class="p-2 border align-self-sm-start">Item 3</div> <div class="p-2 border">Item 4</div> </div>
大萤幕
<div class="d-flex bg-primary" style="height:200px"> <div class="p-2 border">Item 1</div> <div class="p-2 border">Item 2</div> <div class="p-2 border align-self-lg-start">Item 3</div> <div class="p-2 border">Item 4</div> </div>
让我们看一个完整的示例，以从头开始在不同的屏幕上对齐弹性项目：
<!DOCTYPE html> <html lang="en"> <head> <title>Bootstrap Example</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css"> <script src="https://cdn.staticfile.org/jquery/3.3.1/jquery.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script> </head> <body> <div class="container mt-3"> <h1>Align Specific Flex Item from the start</h1> <div class="d-flex bg-info" style="height:200px"> <div class="p-2 border">Item 1</div> <div class="p-2 border">Item 2</div> <div class="p-2 border align-self-start">Item 3</div> <div class="p-2 border">Item 4</div> </div> <h2>Small Screen Size</h2> <div class="d-flex bg-info" style="height:200px"> <div class="p-2 border">Item 1</div> <div class="p-2 border">Item 2</div> <div class="p-2 border align-self-sm-start">Item 3</div> <div class="p-2 border">Item 4</div> </div> <h2>Medium Screen Size</h2> <div class="d-flex bg-primary" style="height:200px"> <div class="p-2 border">Item 1</div> <div class="p-2 border">Item 2</div> <div class="p-2 border align-self-md-start">Item 3</div> <div class="p-2 border">Item 4</div> </div> <h2>Large Screen Size</h2> <div class="d-flex bg-info" style="height:200px"> <div class="p-2 border">Item 1</div> <div class="p-2 border">Item 2</div> <div class="p-2 border align-self-lg-start">Item 3</div> <div class="p-2 border">Item 4</div> </div> </div> </body> </html>