如何在带有 url 的背景的简写属性中使用“background-size : contains”？

Question

下面的 css 正在使用 contains ，因为它单独作为背景大小给出，但不是使用背景中给出的简写

即使我也渴望知道CSS中背景属性的参数顺序

body { 
    background: #00ff00 url("smiley.gif") no-repeat fixed center;
    background-size:contain,contain; 
}

 body { 
    background: #00ff00 url("smiley.gif") no-repeat contain,contain fixed center; 
}  

but this is not working as i tried this shorthand method as above 

<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>
<p>This is some text</p>

单独使用没有问题，但需要知道是否有任何方法可以在简写背景属性中使用background-size:contain

即使你可以通过在 W3School 的示例中进行更改来查看它，这里是它的 url

点击查看您的路线

Answer 1

background: #00ff00 url("smiley.gif") no-repeat fixed center / contain; 

这应该有效。