[英]How to limit the number of selected checkboxes?
我有以下 HTML:
<div class="pricing-levels-3">
<p><strong>Which level would you like? (Select 3 Levels)</strong></p>
<input class="single-checkbox"type="checkbox" name="vehicle" value="Bike">Level 1<br>
<input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 2<br>
<input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 3<br>
<input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 4<br>
<input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 5<br>
<input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 6<br>
<input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 7<br>
</div>
現場直播:
http://www.chineselearnonline.com/amember/signup20.php
我該怎么做才能使用戶只能 select 3 個復選框?
使用change
事件,您可以執行以下操作:
var limit = 3;
$('input.single-checkbox').on('change', function(evt) {
if($(this).siblings(':checked').length >= limit) {
this.checked = false;
}
});
像這樣嘗試。
在更改事件中,
$('input[type=checkbox]').on('change', function (e) {
if ($('input[type=checkbox]:checked').length > 3) {
$(this).prop('checked', false);
alert("allowed only 3");
}
});
在JSFiddle 中檢查這個
試試這個演示:
$(document).ready(function () {
$("input[name='vehicle']").change(function () {
var maxAllowed = 3;
var cnt = $("input[name='vehicle']:checked").length;
if (cnt > maxAllowed)
{
$(this).prop("checked", "");
alert('Select maximum ' + maxAllowed + ' Levels!');
}
});
});
我認為我們應該使用click
而不是change
工作演示
$('.checkbox').click(function(){
if ($('.checkbox:checked').length >= 3) {
$(".checkbox").not(":checked").attr("disabled",true);
}
else
$(".checkbox").not(":checked").removeAttr('disabled');
});
我用過這個。
$("input:checkbox").click(function(){
if ($("input:checkbox:checked").length > 3){
return false;
}
});
嘗試這個
var theCheckboxes = $(".pricing-levels-3 input[type='checkbox']");
theCheckboxes.click(function()
{
if (theCheckboxes.filter(":checked").length > 3)
$(this).removeAttr("checked");
});
我會說就像 letiagoalves 所說的那樣,但是您的表單中可能有多個復選框問題,因此我建議您這樣做:
var limit = 3;
$('input.single-checkbox').on('change', function(evt) {
if($('input.single-checkbox').siblings('input.single-checkbox:checked').length > limit) {
this.checked = false;
}
});
這就是我讓它工作的方式:
// Function to check and disable checkbox
function limit_checked( element, size ) {
var bol = $( element + ':checked').length >= size;
$(element).not(':checked').attr('disabled',bol);
}
// List of checkbox groups to check
var check_elements = [
{ id: '.group1 input[type=checkbox]', size: 2 },
{ id: '.group2 input[type=checkbox]', size: 3 },
];
// Run function for each group in list
$(check_elements).each( function(index, element) {
// Limit checked on window load
$(window).load( function() {
limit_checked( element.id, element.size );
})
// Limit checked on click
$(element.id).click(function() {
limit_checked( element.id, element.size );
});
});
我有更改此功能以自動取消選中以前的
var limit = 3; $('.compare_items').on('click', function(evt) { index = $(this).parent('td').parent('tr').index(); if ($('.compare_items:checked').length >= limit) { $('.compare_items').eq(localStorage.getItem('last-checked-item')).removeAttr('checked'); //this.checked = false; } localStorage.setItem('last-checked-item', index); });
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <input type="checkbox" class="compare_items">1 <input type="checkbox" class="compare_items">2 <input type="checkbox" class="compare_items">3 <input type="checkbox" class="compare_items">4 <input type="checkbox" class="compare_items">5 <input type="checkbox" class="compare_items">6 <input type="checkbox" class="compare_items">7 <input type="checkbox" class="compare_items">8 <input type="checkbox" class="compare_items">9 <input type="checkbox" class="compare_items">10
我今天這樣做了,不同之處在於我想取消選中最舊的復選框,而不是阻止用戶檢查新的復選框:
let maxCheckedArray = [];
let assessmentOptions = jQuery('.checkbox-fields').find('input[type="checkbox"]');
assessmentOptions.on('change', function() {
let checked = jQuery(this).prop('checked');
if(checked) {
maxCheckedArray.push(jQuery(this));
}
if(maxCheckedArray.length >= 3) {
let old_item = maxCheckedArray.shift();
old_item.prop('checked', false);
}
});
如果您想在允許 3 個復選框的情況下取消選中您首先選中的復選框。 使用香草 javascript; 您需要在 html 輸入復選框中分配 onclick = "checking(this)"
var queue = [];
function checking(id){
queue.push(id)
if (queue.length===3){
queue[0].checked = false
queue.shift()
}
}
此功能只是檢查您是否剛剛選中了一個復選框。 如果是,它將checked
值增加一。 如果達到限制,則拒絕下一個復選框。
var limit = 3; var checked = 0; $('.single-checkbox').on('change', function() { if($(this).is(':checked')) checked = checked+1; if($(this).is(':checked') == false) checked = checked-1; if(checked > limit) { this.checked = false; checked = limit; } });
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="pricing-levels-3"> <p><strong>Which level would you like? (Select 3 Levels)</strong></p> <input class="single-checkbox"type="checkbox" name="vehicle" value="Bike">Level 1<br> <input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 2<br> <input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 3<br> <input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 4<br> <input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 5<br> <input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 6<br> <input class="single-checkbox" type="checkbox" name="vehicle" value="Bike">Level 7<br> </div>
此方法適用於容器中的復選框,例如引導復選框
const checkedLimmit = 2;
function ValidateCheckBoxGroup(container) {
if (container.find('input[type="checkbox"]:checked').length >= checkedLimmit) {
container.find('input[type="checkbox"]:not(:checked)').prop('disabled', true);
container.find('input[type="checkbox"]:not(:checked)').closest('div.checkbox').addClass('disabled');
} else {
container.find('input[type="checkbox"]:not(:checked)').prop('disabled', false);
container.find('input[type="checkbox"]:not(:checked)').closest('div.checkbox').removeClass('disabled');
}
}
$(function () {
// validate containers on page load
$('div.checkbox-group').each(function () {
ValidateCheckBoxGroup($(this));
});
// set checkbox events
$('div.checkbox-group input[type="checkbox"]').change(function () {
ValidateCheckBoxGroup($(this).closest("div.checkbox-group"));
});
});
(function ($) {
$(document).ready(function () {
$(document).on("change", ".pricing-levels-3 input", function () {
var numberOfChecked = $(".pricing-levels-3 input:checkbox:checked").length;
if (numberOfChecked >= 2) {
$(".pricing-levels-3 input:not(:checked)").prop("disabled", true);
} else {
$(".pricing-levels-3 input:not(:checked)").removeAttr("disabled", true);
}
});
});
})(jQuery);
這適用於我的復選框名稱。
<script>
// limit checkbox select
$('input[name=vehicle]').on('change', function (e) {
if ($('input[name=vehicle]:checked').length > 3) {
$(this).prop('checked', false);
alert("allowed only 3");
}
});
</script>
JS 和 HTML這對我有用,它的作用是,onclick function checkControl()
將計算復選框被單擊的次數超過 3 次顯示錯誤消息。
function checkboxControl(j) { var total = 0; var elem = document.getElementsByClassName("checkbox"); var error = document.getElementById("error"); for (var i = 0; i < elem.length; i++) { if (elem[i].checked == true) { total = total + 1; } if (total > 3) { error.textContent = "You Must Select at Least 3"; elem[j].checked = false; return false; } } }
<,DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="viewport" content="width=device-width. initial-scale=1:0" /> <title>Document</title> </head> <body> <form action=""> <span id="error" style="color: red"></span> <br> <span>Python</span> <input type="checkbox" class="checkbox" name="interest[]" onclick="checkboxControl(0)" id="1" /> <br> <span>Javascript</span> <input type="checkbox" class="checkbox" name="interest[]" onclick="checkboxControl(1)" id="1" /><br> <span>Go</span> <input type="checkbox" class="checkbox" name="interest[]" onclick="checkboxControl(2)" id="1" /><br> <span>Laravel</span> <input type="checkbox" class="checkbox" name="interest[]" onclick="checkboxControl(3)" id="1" /> </form> </body> </html>
這些資源幫助我理解了 https://www.plus2net.com/javascript_tutorial/checkbox-limit-demo2.php
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