如何交替设置每三个html表格行的不同背景颜色答案

【问题标题】：How to set different background color of every three html table rows in alternate如何交替设置每三个html表格行的不同背景颜色
【发布时间】：2017-07-05 17:05:59
【问题描述】：

假设我有两个名为 table1 和 table2 的 HTML 表。如果我想对 table2 的每三行有不同的背景，我该如何使用 CSS 来实现？例如，将前 3 行的背景设置为蓝色，然后将另外 3 行设置为绿色，再将另外 3 行设置为蓝色，再将另外 3 行设置为绿色，依此类推。基本上我希望每三行交替使用两种不同的背景颜色。我发现了偶数行和奇数行或每第 n 行的 CSS 样式，但不适用于这种情况。我附上了示例表的屏幕截图。我不想像在这段代码中那样在单个行中硬编码，而是想用 CSS 样式来做。

table {
  font-family: arial, sans-serif;
  border-collapse: collapse;
  width: 100%;
}

td,
th {
  border: 1px solid #dddddd;
  text-align: left;
  padding: 1px;
}

<table id="table2">
  <tr>
    <th>Company</th>
    <th>Contact</th>
    <th>Country</th>
  </tr>
  <tr bgcolor="#dddddd">
    <td>Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td>Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td>Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>Island Trading</td>
    <td>Helen Bennett</td>
    <td>UK</td>
  </tr>
  <tr>
    <td>Laughing Bacchus Winecellars</td>
    <td>Yoshi Tannamuri</td>
    <td>Canada</td>
  </tr>
  <tr>
    <td>Magazzini Alimentari Riuniti</td>
    <td>Giovanni Rovelli</td>
    <td>Italy</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td>Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td>Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td>Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
</table>

感谢任何帮助]1

【问题讨论】：

标签： javascript html css

【解决方案1】：

您可以使用“nth-child”来实现这一点。

tr:nth-child(6n+1),
tr:nth-child(6n+2),
tr:nth-child(6n+3) {
  background: #dddddd;
}

试试下面的sn-p

table {
  font-family: arial, sans-serif;
  border-collapse: collapse;
  width: 100%;
}

td, th {
  border: 1px solid #dddddd;
  text-align: left;
  padding: 1px;
}
tr:nth-child(6n+1),
tr:nth-child(6n+2),
tr:nth-child(6n+3) {
  background: #dddddd;
}

<table id="table2">
  <tr>
    <th>Company</th>
    <th>Contact</th>
    <th>Country</th>
  </tr>
  <tr>
    <td >Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr>
    <td >Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr>
    <td >Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>Island Trading</td>
    <td>Helen Bennett</td>
    <td>UK</td>
  </tr>
  <tr>
    <td>Laughing Bacchus Winecellars</td>
    <td>Yoshi Tannamuri</td>
    <td>Canada</td>
  </tr>
  <tr>
    <td>Magazzini Alimentari Riuniti</td>
    <td>Giovanni Rovelli</td>
    <td>Italy</td>
  </tr>
  <tr>
    <td >Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr>
    <td >Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr>
    <td >Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
</table>

【讨论】：

既然这也选择了表头，为什么不使用6n+2、6n+3和6n+4
这哥们太棒了

【解决方案2】：

您希望每三组行使用另一种颜色。让我们解释一下 css tr:nth-child(6n+1), tr:nth-child(6n+2), tr:nth-child(6n+3) 的公式，其中 n=0,1,2,3......这个tr 选择将从 1-3、7-9....开始。

同样tr:nth-child(6n+4), tr:nth-child(6n+5), tr:nth-child(6n+6)，其中 n=0,1,2,3……此tr 选择将从 4-6、10-12...开始。

tr:nth-child(6n+1),
tr:nth-child(6n+2),
tr:nth-child(6n+3) {
  background: blue;
}

tr:nth-child(6n+4),
tr:nth-child(6n+5),
tr:nth-child(6n+6) {
  background: green;
}

table {
  color: #fff;
}

<table id="table2">
  <tr>
    <th>Company</th>
    <th>Contact</th>
    <th>Country</th>
  </tr>
  <tr>
    <td>Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr>
    <td>Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr>
    <td>Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>Island Trading</td>
    <td>Helen Bennett</td>
    <td>UK</td>
  </tr>
  <tr>
    <td>Laughing Bacchus Winecellars</td>
    <td>Yoshi Tannamuri</td>
    <td>Canada</td>
  </tr>
  <tr>
    <td>Magazzini Alimentari Riuniti</td>
    <td>Giovanni Rovelli</td>
    <td>Italy</td>
  </tr>
  <tr>
    <td>Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr>
    <td>Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr>
    <td>Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
</table>

现在您将根据需要获得蓝色和绿色的替代颜色

【讨论】：

【解决方案3】：

您可以使用 javascript 设置背景颜色

 $('document').ready(function(){
     $('#table1 tr').each((index, value) => {
         if(index % 3 != 0){
             value.css({'background-color': '#0000FF'});
         }else{
             value.css({'background-color': '#00FF00'});
         }
     });
});

或者定义两个css类

.blue {background-color: #0000FF;}
.green {background-color: #00FF00;}

并在你想要的所有 tr 表中分配这个类

【讨论】：

非常感谢！

【解决方案4】：

你可以将header和body分开，使用nth-child概念

<!DOCTYPE html>
<html>
<head>
<style>
table {
    font-family: arial, sans-serif;
    border-collapse: collapse;
    width: 100%;
}

table tbody tr:nth-child(6n+1),table tbody tr:nth-child(6n+2),table tbody 
tr:nth-child(6n+3) {
     background: #dddddd;
}

td, th {
    border: 1px solid #dddddd;
    text-align: left;
    padding: 1px;
}


</style>
</head>
<body>

<table id="table2">
<thead>
  <tr>
    <th>Company</th>
    <th>Contact</th>
    <th>Country</th>
  </tr>
</thead>
<tbody>
  <tr bgcolor="#dddddd">
    <td >Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td >Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td >Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>Island Trading</td>
    <td>Helen Bennett</td>
    <td>UK</td>
  </tr>
  <tr>
    <td>Laughing Bacchus Winecellars</td>
    <td>Yoshi Tannamuri</td>
    <td>Canada</td>
  </tr>
  <tr>
    <td>Magazzini Alimentari Riuniti</td>
    <td>Giovanni Rovelli</td>
    <td>Italy</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td >Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td >Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr bgcolor="#dddddd">
    <td >Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
  <tr>
    <td>a</td>
    <td>b</td>
    <td>c</td>
  </tr>
<tbody>
</table>

</body>
</html>

【讨论】：

【解决方案5】：

<html>
<head>
<title></title>
<style>
    .green{background-color:white;}
    .blue{background-color:gray;}
</style>
<script>

function alterColor(id){
        var table = document.getElementById(id);
        var rows = table.getElementsByTagName("tr");    //get all the rows
        for(i = 0; i < rows.length; i++){               //alterColor styles         
            doalterColor(rows[i], i);

        }
}
function doalterColor(row, i){
if((i % 6 == 0) ||(i % 6 == 1)||(i % 6 == 2)){
        row.className = "blue";
    }else{
        row.className = "green";
    }
}
</script>
</head>
<body onLoad="alterColor('mytable')">

<table id="mytable">
    <tr>
    <td>cell 1</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 2</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 3</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 4</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 5</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 6</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 7</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 8</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 9</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 10</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 11</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 12</td>
    <td>cell 2</td>
  </tr><tr>
    <td>cell 13</td>
    <td>cell 2</td>
  </tr>
</table>
</body>

【讨论】：