取消选中一个复选框时,如何启用所有复选框?使用javascript

How to enable all checkbox when one checkbox is deselected ? using javascript

本文关键字:复选框 启用 javascript 使用 何启用 一个 取消      更新时间:2024-01-01

当我选中一个复选框时,我的代码就会工作,所有复选框都会被禁用。现在我想如果我取消选中这个复选框,所有复选框都应该被启用。以下是我尝试过的

<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '80' onclick='return(validate())'>Q- 80. Statute of Liberty is in ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '153' onclick='return(validate())'>Q- 153. Indias Republic day is celebrated on ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '65' onclick='return(validate())'>Q- 65. Popular Language is ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '150' onclick='return(validate())'>Q- 150. Girnar is located at ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '154' onclick='return(validate())'>Q- 154. Largest Waterfall ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '152' onclick='return(validate())'>Q- 152. Asia is an ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '139' onclick='return(validate())'>Q- 139. Diamond is made up of ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '123' onclick='return(validate())'>Q- 123. Largest Desert ? </td> </tr>

JS:这个javascript是当选中一个复选框时,所有复选框都会被禁用。我希望反之亦然,当一个人取消选中复选框时,所有的都应该启用

function validate(){
            for (i=0; i<document.myForm.check1.length; i++){
                if (document.myForm.check1[i].checked !=true){
                    document.myForm.check1[i].disabled='true';
                }
            }
 }

如果您坚持使用javascript而不是jQuery,因为这在jQuery中可能非常简单,请查看此处:

http://jsfiddle.net/CYLmn/18/

function validate(thisobj){
        if(thisobj.checked==true){
            for (i=0; i<document.myForm.check1.length; i++){
                if (document.myForm.check1[i].checked !=true){
                    document.myForm.check1[i].disabled='true';
                }
            }
        } else {
            for (i=0; i<document.myForm.check1.length; i++){
                document.myForm.check1[i].disabled='';
            }
        }
 }
<script>
    function validate(element){
        for (i=0; i<document.myForm.check1.length; i++){
            if (!(document.myForm.check1[i].checked)){
                document.myForm.check1[i].disabled=true;
            }
            if(!(element.checked)){
                document.myForm.check1[i].disabled=false;
            }
            element.disabled=false;
        }
    }
</script>
<form name="myForm" id="myForm">
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '80' onclick='return(validate(this))'>Q- 80. Statute of Liberty is in ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '153' onclick='return(validate(this))'>Q- 153. Indias Republic day is celebrated on ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '65' onclick='return(validate(this))'>Q- 65. Popular Language is ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '150' onclick='return(validate(this))'>Q- 150. Girnar is located at ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '154' onclick='return(validate(this))'>Q- 154. Largest Waterfall ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '152' onclick='return(validate(this))'>Q- 152. Asia is an ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '139' onclick='return(validate(this))'>Q- 139. Diamond is made up of ? </td> </tr>
<tr> <td colspan='3'> <input type='checkbox' name='check1' value = '123' onclick='return(validate(this))'>Q- 123. Largest Desert ? </td> </tr>
</form>

试试这个

在For循环的First if条件检查每个元素是否被检查时,它会禁用未被检查的元素。

在第二个If条件中,它检查单击的元素是否未被选中,并启用所有元素。。

并且最终它启用了被点击的元素。

相当困惑,但符合目的。。。

需要提及的几件事:

  • 一旦你确认了结果,最好还是启用那个复选框
  • 您不需要将onclick添加到所有复选框中——它效率不高,难以维护,并且会为每个这样的声明生成后台匿名函数;您可以将事件附加到所有复选框的父项,只需选中事件的目标即可过滤掉所有未发布的元素

这是我为您提供的解决方案:

HTML

<form id="myForm">
  <table>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '80'>Q- 80. Statute of Liberty is in ? </td> </tr>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '153'>Q- 153. Indias Republic day is celebrated on ? </td> </tr>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '65'>Q- 65. Popular Language is ? </td> </tr>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '150'>Q- 150. Girnar is located at ? </td> </tr>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '154'>Q- 154. Largest Waterfall ? </td> </tr>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '152'>Q- 152. Asia is an ? </td> </tr>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '139'>Q- 139. Diamond is made up of ? </td> </tr>
    <tr> <td colspan='3'> <input type='checkbox' name='check1' value = '123'>Q- 123. Largest Desert ? </td> </tr>
  </table>
</form>

JavaScript

function listen(element, event, callback) {
  if(element.attachEvent) { // IE
    element.attachEvent('on'+event, callback);
  } else { // W3C
    element.addEventListener(event, callback);
  }
}
var form = document.querySelector('#myForm');
listen(form, 'click', function(event){
  var checkBoxes, i, checked, target;
  target = event.srcElement || event.target; // IE or W3C 
  if(target.getAttribute('name') === 'check1') {
    checkBoxes = form.querySelectorAll('input[name="check1"]');
    checked = target.checked;
    for(i=0;i<checkBoxes.length;i++) {
      checkBoxes[i].disabled = checked && checkBoxes[i] !== target;
    }
    if(checked) {
      // Validate and do something with result (target.value)
    } else {
      // Reset validation and result
    }
  }
});

以下是一个工作示例:http://jsbin.com/iKiNenA/10/edit

注意:应该将<script>...</script>放在<form>...</form>之后,以确保它在加载表单DOM后运行。否则,使用document.onload = funciton() { ... }包装代码

使用jQuery,您可以将javascript代码简化为:

$(function() {
  $('#myForm').on('click', 'input[name="check1"]', function(event) {
    $('#myForm input[name="check1"]').prop('disabled', event.target.checked);
    event.target.disabled = false;
    if(event.target.checked) {
      // Validate and do something with result (event.target.value)
    } else {
      // Reset validation and result
    }
  });
});

示例:http://jsbin.com/iKiNenA/9/edit

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