这是对之前答案的一种尝试，以自动保留具有特定值(在本例中为0)的未选中复选框，而不会在提交时选中所有复选框。

$("form").submit(function () {
    let this_master = $(this);

    // Remove any of the hidden values that may already be there (if the user previously canceled the submit)
    this_master.find("*[id^='hiddenchkinput_']").remove();

    // Get all unchecked checkboxes
    this_master.find('input:checkbox:not(:checked)').each(function () {
      let thisChk = $(this);

      // Create a hidden input with the same name as the checkbox
      let newInput = document.createElement('input');
      $(newInput).attr('name', thisChk.attr('id'))
        .attr('id', 'hiddenchkinput_' + thisChk.attr('id'))
        .attr('type', 'hidden')
        .val('0');
      // Append the new input to the end of the form
      this_master.append(newInput);
    });
})

function SubmitCheckBox(obj) {
     obj.value   = obj.checked ? "on" : "off";
     obj.checked = true;
     return obj.form.submit();
}

<input type=checkbox name="foo" onChange="return SubmitCheckBox(this);">

您可以在提交表单之前添加隐藏元素。

$('form').submit(function() {
  $(this).find('input[type=checkbox]').each(function (i, el) {
    if(!el.checked) {
      var hidden_el = $(el).clone();
      hidden_el[0].checked = true;
      hidden_el[0].value = '0';
      hidden_el[0].type = 'hidden'
      hidden_el.insertAfter($(el));
    }
  })
});

Checkboxes usually represent binary data that are stored in database as Yes/No, Y/N or 1/0 values. HTML checkboxes do have bad nature to send value to server only if checkbox is checked! That means that server script on other site must know in advance what are all possible checkboxes on web page in order to be able to store positive (checked) or negative (unchecked) values. Actually only negative values are problem (when user unchecks previously (pre)checked value - how can server know this when nothing is sent if it does not know in advance that this name should be sent). If you have a server side script which dynamically creates UPDATE script there's a problem because you don't know what all checkboxes should be received in order to set Y value for checked and N value for unchecked (not received) ones.

由于我在数据库中存储值“Y”和“N”，并通过页面上的选中和未选中复选框表示它们，我为每个值(复选框)添加了“Y”和“N”值的隐藏字段，然后使用复选框进行可视化表示，并使用简单的JavaScript函数check()来根据选择设置if的值。

<input type="hidden" id="N1" name="N1" value="Y" />
<input type="checkbox"<?php if($N1==='Y') echo ' checked="checked"'; ?> onclick="check(this);" />
<label for="N1">Checkbox #1</label>

使用一个JavaScript onclick监听器和调用函数check()在我的网页上的每个复选框:

function check(me)
{
  if(me.checked)
  {
    me.previousSibling.previousSibling.value='Y';
  }
  else
  {
    me.previousSibling.previousSibling.value='N';
  }
}

这样，“Y”或“N”值总是发送到服务器端脚本，它知道什么是应该更新的字段，没有必要将复选框“上”值转换为“Y”或未接收复选框转换为“N”。

注意:空格或新行也是兄弟姐妹，所以这里我需要。previoussibling . previoussibling .value。如果没有空格，则只有.previousSibling.value

你不需要像以前那样显式地添加onclick监听器，你可以使用jQuery库动态添加点击监听器函数来更改页面中所有复选框的值:

$('input[type=checkbox]').click(function()
{
  if(this.checked)
  {
    $(this).prev().val('Y');
  }
  else
  {
    $(this).prev().val('N');
  }
});

直接复制 美元(文档)。On ('change'， "input[type=checkbox]"， function () { var checkboxVal = (this.checked) ?1: 0; if (checkboxVal== 1) { (美元)。道具(“检查”,真正的); (美元).val(“true”); ｝ 其他{ (美元)。道具(“检查”,假); (美元).val(“false”); ｝ })；

当提交时复选框未选中时，将复选框的值更新为'NO'并设置checked = 'TRUE'

https://jsfiddle.net/pommyk/8d9jLrvo/26/

$(document).ready(function() 
{
  function save() 
  {
    if (document.getElementById('AgeVerification').checked == false) 
    {
      document.getElementById('AgeVerification').value = 'no';
      document.getElementById('AgeVerification').checked = true;     
    }
  }
  document.getElementById("submit").onclick = save;
})