d3.js selection.each()用法及代码示例

D3.js中的selection.each()函数用于为每个选定的HTML元素调用特定函数。在函数中，datum(d)和index(i)作为参数给出。通过使用此方法，可以同时访问父数据和子数据。

用法:

selection.each(callback);

参数：该函数接受如上所述和以下描述的单个参数。

callback:这是每个选定元素调用的函数。

返回值：此函数不返回任何内容。

下面给出的是上面给出的函数的一些例子。

范例1：

HTML

<!DOCTYPE html> 
<html lang="en"> 
    <head> 
        <meta charset="UTF-8" /> 
        <meta
            name="viewport"
            path1tent="width=device-width,  
                       initial-scale=1.0"/> 
        <title>  D3.js selection.each() Function</title> 
    </head> 
    <style> 
        .div { 
            width:200px; 
            height:200px; 
            background-color:green; 
            overflow:hidden; 
        } 
        div { 
            background-color:red; 
            width:10px; 
            height:10px; 
        } 
    </style> 
    <body> 
        <ul> 
            <li>Geeks for geeks</li> 
            <li>Some text</li> 
        </ul> 
        <ul> 
            <li>List tag</li> 
            <li>each function</li> 
        </ul> 
        <button>Click me</button> 
        <script src= 
"https://d3js.org/d3.v4.min.js"> 
        </script> 
        <script src= 
"https://d3js.org/d3-selection.v1.min.js"> 
        </script> 
        <script> 
            let btn = document.querySelector("button"); 
            let func = () => { 
                let p = d3.selectAll("ul"); 
                p.each(function (p, j) { 
                    d3.select(this) 
                        .selectAll("li") 
                        .text(function (d, i) { 
                            return "child are edited."; 
                        }); 
                }); 
            }; 
            btn.addEventListener("click", func); 
        </script> 
    </body> 
</html>

输出：

在单击按钮之前：

单击按钮后：

范例2：

HTML

<!DOCTYPE html> 
<html lang="en"> 
    <head> 
        <meta charset="UTF-8" /> 
        <meta
            name="viewport"
            path1tent="width=device-width,  
                       initial-scale=1.0"/> 
        <title>D3.js selection.each() Function</title> 
    </head> 
    <style> 
        div { 
            background-color:green; 
            margin-bottom:5px; 
            padding:10px; 
            width:fit-content; 
        } 
    </style> 
    <body> 
        <div>Some text</div> 
        <div>Geeks</div> 
        <div>Geeks for geeks</div> 
        <div>Some text</div> 
        <button>Click me</button> 
        <script src= 
"https://d3js.org/d3.v4.min.js"> 
        </script> 
        <script src= 
"https://d3js.org/d3-selection.v1.min.js"> 
        </script> 
        <script> 
            let btn = document.querySelector("button"); 
            let func = () => { 
                let p = d3.selectAll("div"); 
                console.log(p); 
                p.each(function (p, j) { 
                    console.log("p:" + p, "j:" + j); 
                    d3.select(this).text(function (d, i) { 
                        return "DIVs are edited."; 
                    }); 
                }); 
            }; 
            btn.addEventListener("click", func); 
        </script> 
    </body> 
</html>

输出：

在单击按钮之前：

单击按钮后：

相关用法

注：本文由纯净天空筛选整理自tarun007大神的英文原创作品 D3.js selection.each() Function。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。