Javascript implements email display and deletion functions_javascript skills

1. Main introduction:
This question uses the previous technology, based on the rows attribute of the table, obtains the array, and then sets the style on the array, so the color comes out.

1). Select all check boxes , pass var nodess=document.getElementsByName("mail");

for(var x=0;x<nodess.length;x++){

nodess[x].checked=nodes.checked;

}

Checkbox function

2). The button selects all, inverts the selection, and deselects all. can be written with a function, and different parameter AllBybtn (num) types can be passed in

In the function, the two states of non-0 and 0 are set according to the characteristics of js. For synchronization, they need to be set separately

3).In order to display that all check boxes are selected by default when all are selected, it is necessary to set each check box and use the function checkBysingle() to set it

4).It is necessary to delete the selected item. The current one is the checkbox object. The upper level is td--tr--get the tr object first, and then delete the tr from the parent node passing tr. After the object is deleted, x will change, and some objects may not be deleted, so you need to restore the value of X or delete it from the back.

2. Style setting:

<style type="text/css"> 
      .one{ 
        background-color:#00ff80; 
      } 
      .two{ 
        background-color:#80ff00; 
      } 
      .three{ 
        background-color:#0000ff; 
      } 
      table th{ 
        background-color:#c0c0c0; 
      } 
      table{ 
        width:400px; 
        border:solid 1px; 
      } 
      table tr{ 
        height:50px; 
      } 
    </style> 

3. Background color and mouse movement event settings

  function toaddcolor(){ 
          //颜色设置， 
          var nodes = document.getElementById("tabid"); 
          var rows1 = nodes.rows; 
          for (var x = 1; x < rows1.length; x++) { 
            if (x % 2 == 0) { 
              rows1[x].className = "one"; 
            } 
            else { 
              rows1[x].className = "two"; 
            } 
          } 
        } 
          function addEvent(){ 
            var name; 
            //当鼠标移上去之后发生相应的变化 
            var nodes=document.getElementById("tabid"); 
            var rows1=nodes.rows; 
            for (var x = 1; x < rows1.length; x++) { 
            rows1[x].onmouseover = function(){ 
              name = this.className; 
              this.className = "three"; 
            } 
            rows1[x].onmouseout = function(){ 
              this.className = name; 
            } 
             
//             alert("bb"); 
//             alert(rows1[x].getElementsByTagName("input")[0].nodeName); 
            rows1[x].getElementsByTagName("input")[0].onclick=function(){//每一行的input对象 
              document.getElementsByName("allItem")[0].indeterminate=true;//让全选的复选框形状发生变化 
            } 
          } 
        } 
        onload=function(){//在网页加载时候调用 
          toaddcolor(); 
          addEvent(); 
        } 

4. Select all check boxes

function allcheck(nodes){//全选checkbox的点击调用这个 
          var nodess=document.getElementsByName("mail"); 
          for(var x=0;x<nodess.length;x++){ 
            nodess[x].checked=nodes.checked; 
          } 
          //多个全选的时候，必须和其他的一个一样 
          var nodes1=document.getElementsByName("allItem"); 
          for(var x=0;x<nodes1.length;x++){ 
            nodes1[x].checked=nodes.checked; 
          } 
        } 

5. Select all buttons

function AllBybtn(num){//全选按钮设置 
          var nodess = document.getElementsByName("mail"); 
          /*多重for 循环不太好，可以根据js里面的特性0  非0 
           for (var x = 0; x < nodess.length; x++) { 
            if (num == 1) { 
              nodess[x].checked = 1; 
            }else if (num == 2) { 
                nodess[x].checked = !nodess[x].checked; 
              }else if (num == 3) { 
                  nodess[x].checked = false; 
                } 
          }*/ 
          for(var x=0;x<nodess.length;x++){ 
            if(num<2){ 
              nodess[x].checked=num; 
                //让全选的复选框可以 单独写个函数 
                var all=document.getElementsByName("allItem"); 
                for(var y=0;y<all.length;y++){ 
                  if(num==1){ 
                  all[y].checked=num; 
                }else{ 
                  all[y].checked=num; 
                } 
              } 
            }else{ 
              nodess[x].checked=!nodess[x].checked; 
              var all=document.getElementsByName("allItem"); 
                for (var y = 0; y < all.length; y++) { 
                  all[y].checked=0; 
                }}}} 

6. After all items are selected, select them all and select them automatically

function checkBysingle(){//全部入选之后，全选的自动选中      
          var flag = true; 
          var node = document.getElementsByName("mail"); 
          for (var x = 0; x < node.length; x++) { 
            if (node[x].checked == false) { 
              flag = false; 
              break; 
            } 
          } 
           
          var all = document.getElementsByName("allItem"); 
          for (var y = 0; y < all.length; y++) { 
            if (flag) { 
              all[y].checked = true; 
            } 
            else { 
              all[y].checked = false; 
            }}} 

7. Function to delete emails (delete rows)

function DelBybtn(){//删除行 
  var tdnode=document.getElementsByName("mail"); 
    /*for(var x=0;x<tdnode.length;x++){ 
    if(tdnode[x].checked){//对象是 checkbox 我们必须要那父级的父级 《tr》，我们需要移除的就是tr对象 
       var trnode=tdnode[x].parentNode.parentNode;//tr对象 
       trnode.parentNode.removeChild(trnode);//table对象移除tr对象 
    // alert("aa"); 
    //节点容器跟Java当中的集合一样，只要是remove()，长度就会变的。这里，需要进行x的复位 
      x--; 
    }*/ 
    for(var x=tdnode.length-1;x>=0;x--){ 
      if(tdnode[x].checked){//对象是 checkbox 我们必须要那父级的父级 《tr》，我们需要移除的就是tr对象 
       var trnode=tdnode[x].parentNode.parentNode;//tr对象 
       trnode.parentNode.removeChild(trnode);//table对象移除tr对象 
    } 
    loading();//调用颜色的设置 
  } 
} 

Phenomena 1:

Reverse election effect:

Before deletion:

After deletion:

Full code:

<!DOCTYPE html> 
<html> 
 <head> 
  <!-- 
    这题采用之前的技术，根据table的rows属性，获得数组，然后对数组设置样式，所以颜色就出来了 
    1，全选复选框，通过var nodess=document.getElementsByName("mail"); 
          for(var x=0;x<nodess.length;x++){ 
            nodess[x].checked=nodes.checked; 
          } 
    复选框函数进行 
    2，按钮全选，反选，和取消全选，可以用一个函数写，传入不同的参数AllBybtn(num）类型即可 
    函数里面 根据js的特性 非0 和 0 这两种状态，进行设置，为了同步，需要分别进行设置 
    3，为了显示出当全部选中就默认全选的复选框选中，所以需要对每一个复选框进行设置，采用函数checkBysingle()进行设置 
    4,删除所选项是需要主要，当前的是checkbox对象，上一级是td--tr--先拿到tr对象，然后对通过tr的父节点删除tr对象 
      再删除之后，x会变化，可能有些删不到，所以需要将X的值还原，或者从后面开始删除 
  --> 
  <title>Mail.html</title> 
    <style type="text/css"> 
      .one{ 
        background-color:#00ff80; 
      } 
      .two{ 
        background-color:#80ff00; 
      } 
      .three{ 
        background-color:#0000ff; 
      } 
      table th{ 
        background-color:#c0c0c0; 
      } 
      table{ 
        width:400px; 
        border:solid 1px; 
      } 
      table tr{ 
        height:50px; 
      } 
    </style> 
    <script type="text/javascript"> 
        var name; 
        function toaddcolor(){ 
          //颜色设置， 
          var nodes = document.getElementById("tabid"); 
          var rows1 = nodes.rows; 
          for (var x = 1; x < rows1.length; x++) { 
            if (x % 2 == 0) { 
              rows1[x].className = "one"; 
            } 
            else { 
              rows1[x].className = "two"; 
            } 
          } 
        } 
          function addEvent(){ 
            var name; 
            //当鼠标移上去之后发生相应的变化 
            var nodes=document.getElementById("tabid"); 
            var rows1=nodes.rows; 
            for (var x = 1; x < rows1.length; x++) { 
            rows1[x].onmouseover = function(){ 
              name = this.className; 
              this.className = "three"; 
            } 
            rows1[x].onmouseout = function(){ 
              this.className = name; 
            } 
             
//             alert("bb"); 
//             alert(rows1[x].getElementsByTagName("input")[0].nodeName); 
            rows1[x].getElementsByTagName("input")[0].onclick=function(){//每一行的input对象 
              document.getElementsByName("allItem")[0].indeterminate=true;//让全选的复选框形状发生变化 
            } 
          } 
        } 
        onload=function(){//在网页加载时候调用 
          toaddcolor(); 
          addEvent(); 
        } 
        function allcheck(nodes){//全选checkbox的点击调用这个 
          var nodess=document.getElementsByName("mail"); 
          for(var x=0;x<nodess.length;x++){ 
            nodess[x].checked=nodes.checked; 
          } 
          //多个全选的时候，必须和其他的一个一样 
          var nodes1=document.getElementsByName("allItem"); 
          for(var x=0;x<nodes1.length;x++){ 
            nodes1[x].checked=nodes.checked; 
          } 
        } 
        function AllBybtn(num){//全选按钮设置 
          var nodess = document.getElementsByName("mail"); 
          /*多重for 循环不太好，可以根据js里面的特性0  非0 
           for (var x = 0; x < nodess.length; x++) { 
            if (num == 1) { 
              nodess[x].checked = 1; 
            }else if (num == 2) { 
                nodess[x].checked = !nodess[x].checked; 
              }else if (num == 3) { 
                  nodess[x].checked = false; 
                } 
          }*/ 
          for(var x=0;x<nodess.length;x++){ 
            if(num<2){ 
              nodess[x].checked=num; 
                //让全选的复选框可以 单独写个函数 
                var all=document.getElementsByName("allItem"); 
                for(var y=0;y<all.length;y++){ 
                  if(num==1){ 
                  all[y].checked=num; 
                }else{ 
                  all[y].checked=num; 
                } 
              } 
            }else{ 
              nodess[x].checked=!nodess[x].checked; 
              var all=document.getElementsByName("allItem"); 
                for (var y = 0; y < all.length; y++) { 
                  all[y].checked=0; 
                } 
            } 
          } 
        } 
         
        function checkBysingle(){//全部入选之后，全选的自动选中 
          var flag = true; 
          var node = document.getElementsByName("mail"); 
          for (var x = 0; x < node.length; x++) { 
            if (node[x].checked == false) { 
              flag = false; 
              break; 
            } 
          } 
           
          var all = document.getElementsByName("allItem"); 
          for (var y = 0; y < all.length; y++) { 
            if (flag) { 
              all[y].checked = true; 
            } 
            else { 
              all[y].checked = false; 
            }}} 
       
      function DelBybtn(){//删除行 
        var tdnode=document.getElementsByName("mail"); 
          /*for(var x=0;x<tdnode.length;x++){ 
          if(tdnode[x].checked){//对象是 checkbox 我们必须要那父级的父级 《tr》，我们需要移除的就是tr对象 
             var trnode=tdnode[x].parentNode.parentNode;//tr对象 
             trnode.parentNode.removeChild(trnode);//table对象移除tr对象 
          // alert("aa"); 
          //节点容器跟Java当中的集合一样，只要是remove()，长度就会变的。这里，需要进行x的复位 
            x--; 
          }*/ 
           
          for(var x=tdnode.length-1;x>=0;x--){ 
            if(tdnode[x].checked){//对象是 checkbox 我们必须要那父级的父级 《tr》，我们需要移除的就是tr对象 
             var trnode=tdnode[x].parentNode.parentNode;//tr对象 
             trnode.parentNode.removeChild(trnode);//table对象移除tr对象 
          } 
          toaddcolor(); 
          addEvent(); 
        } 
      } 
    </script>    
 </head> 
  
 <body> 
  <table id="tabid"> 
    <tr> <th><input type="checkbox" name="allItem" onclick="allcheck(this)"/> 全选 </th> <th>发件人</th> <th>邮件标题</th> <th>邮件附属信息</th></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>张三</td> <td>国庆祝福</td> <td>邮件附属信息1....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Jack</td> <td>假期堵车</td> <td>邮件附属信息2....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Jack</td> <td>假期堵车</td> <td>邮件附属信息3....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Jack</td> <td>假期堵车</td> <td>邮件附属信息4....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Jack</td> <td>假期堵车</td> <td>邮件附属信息5....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Tom</td> <td>一些广告</td> <td>邮件附属信息6....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Tom</td> <td>一些广告</td> <td>邮件附属信息6....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Tom</td> <td>一些广告</td> <td>邮件附属信息6....</td></tr> 
    <tr> <td><input type="checkbox" name="mail" onclick="checkBysingle(this)" /> </td> <td>Tom</td> <td>一些广告</td> <td>邮件附属信息6....</td></tr> 
    <tr><td><input type="checkbox"  name="allItem" onclick="allcheck(this)">全选</td> 
      <td colspan=3><input type="button" value="全选" name="btn1" onclick="AllBybtn(1)" /> 
      <input type="button" value="反选" name="btn2" onclick="AllBybtn(2)"/> 
      <input type="button" value="取消全选" name="btn3" onclick="AllBybtn(0)"/> 
      <input type="button" value="删除所选项" name="btn4" onclick="DelBybtn()"/> 
       
       
      </td> 
    </tr> 
  </table> 
 </body> 
</html> 

I hope this article will be helpful to everyone learning JavaScript programming.