我刚刚在this other question中看到了这段代码，但我不明白它是如何工作的：
let Parent = ({api}) => (
<ApiSubscribe>
<Child api={api} />
</ApiSubscribe>
)
我了解类似这样的内容：
{foo => <Bar bar={bar} />}但以前从未在渲染中看到* {margin: 0; padding: 0;}
.scrollbtn {
float: right;
cursor: pointer;
margin: 5px;
padding: 5px;
border: 1px solid #ccc;
color: #ccc;
border-radius: 5px;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
-webkit-user-select: none; /* Chrome/Safari */
-moz-user-select: none; /* Firefox */
-ms-user-select: none; /* IE10+ */
}
.scrollbtn:hover {
background: #c8e4f8; color: #000; border: 1px solid #94a0b4;
}
#c1 {
width: 96%;
overflow: auto;
padding: 2%;
}
#c2 {
width: 100000px;
}
.tree ul {
padding-top: 20px; position: relative;
-webkit-transition: all 0.5s;
-moz-transition: all 0.5s;
transition: all 0.5s;
}
.tree li {
float: left; text-align: center;
list-style-type: none;
position: relative;
padding: 20px 5px 0 5px;
-webkit-transition: all 0.5s;
-moz-transition: all 0.5s;
transition: all 0.5s;
}
/*We will use ::before and ::after to draw the connectors*/
.tree li::before, .tree li::after{
content: '';
position: absolute; top: 0; right: 50%;
border-top: 1px solid #ccc;
width: 50%; height: 32px;
z-index: -1;
}
.tree li::after{
right: auto; left: 50%;
border-left: 1px solid #ccc;
}
/*We need to remove left-right connectors from elements without
any siblings*/
.tree li:only-child::after, .tree li:only-child::before {
display: none;
}
/*Remove space from the top of single children*/
.tree li:only-child{ padding-top: 0;}
.tree li li:only-child{ float: none;}
/*Remove left connector from first child and
right connector from last child*/
.tree li:first-child::before, .tree li:last-child::after{
border: 0 none;
}
/*Adding back the vertical connector to the last nodes*/
.tree li:last-child::before{
border-right: 1px solid #ccc;
border-radius: 0 5px 0 0;
-webkit-transform: translateX(1px);
-moz-transform: translateX(1px);
transform: translateX(1px);
-webkit-border-radius: 0 5px 0 0;
-moz-border-radius: 0 5px 0 0;
border-radius: 0 5px 0 0;
}
.tree li:first-child::after{
border-radius: 5px 0 0 0;
-webkit-border-radius: 5px 0 0 0;
-moz-border-radius: 5px 0 0 0;
}
/*Time to add downward connectors from parents*/
.tree ul ul::before{
content: '';
position: absolute; top: -12px; left: 50%;
border-left: 1px solid #ccc;
width: 0; height: 32px;
z-index: -1;
}
.tree li a{
border: 1px solid #ccc;
padding: 5px 10px;
text-decoration: none;
color: #666;
font-family: arial, verdana, tahoma;
font-size: 11px;
display: inline-block;
background: white;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
-webkit-transition: all 0.5s;
-moz-transition: all 0.5s;
transition: all 0.5s;
}
.tree li a+a {
margin-left: 20px;
position: relative;
}
.tree li a+a::before {
content: '';
position: absolute;
border-top: 1px solid #ccc;
border-bottom: 1px solid #ccc;
top: 47%; left: -21px;
width: 20px;
height: 6%;
}
/*Time for some hover effects*/
/*We will apply the hover effect the the lineage of the element also*/
.tree li a:hover, .tree li a:hover~ul li a {
background: #c8e4f8; color: #000; border: 1px solid #94a0b4;
}
/*Connector styles on hover*/
.tree li a:hover~ul li::after,
.tree li a:hover~ul li::before,
.tree li a:hover~ul::before,
.tree li a:hover~ul ul::before
{
border-color: #94a0b4;
}
a {
width: 130px;
}
有人可以帮助我理解这一点吗？
答案 0 :(得分：3)
组件可以使用children道具访问为其赋予的子元素。如果一个函数作为子函数提供，则组件可以调用此函数。然后，调用children函数的组件可以使用它认为合适的任何参数来调用该函数。
示例
const Child = props => {
return props.children('test');
};
const Parent = () => (
<Child>
{function(arg1) {
return <div> This is a {arg1} </div>;
}}
</Child>
);
ReactDOM.render(<Parent />, document.getElementById("root"));<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="root"></div>