Question

如何通过更改输入值来禁用启用按钮。我想通过远程或从其他输入字段更改其值来在#second只读输入字段中启用“更改”按钮。

$(document).ready(function(){
$('#button').attr('disabled',true);
});
$(document).on('change keyup blur','#first',function(){
   var second= $('#second').val();
   if($(this).val() != '' ){
		sum = parseFloat($(this).val()) + parseFloat(second);
    $('#second').val(sum);
    }
});
$("#second").on('change',function(){
   var second= $(this).val();
   var third= $('#third').val();
  if (second == third) {
     $('#button').attr('disabled',false);
  } else {
	$('#button').attr('disabled',true);	
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="number" id="first" placeholder="first">
<input type="number" id="second" value="5" readonly>
<input type="number" id="third" value="10" readonly>

<input type="button" id="button" value="button" />

Answer 1

试试这个
https://www.w3schools.com/code/tryit.asp?filename=G5YTJB50T072

在您的代码中使用了keyup，change，blur，这使计算不正确，并且始终在document.ready中使用jquery代码（例如change函数）。

谢谢

    <script>
        $(document).ready(function(){
            $('#button').attr('disabled',true);
            $("#second").on('change',function(){
                var second = $(this).val();
                var third = $('#third').val();
                if (second == third) {
                    $('#button').attr('disabled',false);
                } else {
                    $('#button').attr('disabled',true); 
                }
            });
        });
        $(document).on('keyup','#first',function(){
            var second= $('#second').val();
            if($(this).val() != ''){
                sum = parseFloat($(this).val()) + parseFloat(second);
                $('#second').val(sum);
                $('#second').val(sum).trigger('change');
            }
        });
    </script>

Answer 2

您的问题在这一行：

$('#second').val(sum);

更改输入值不会触发更改事件。因此，您可以自己触发它：

$('#second').val(sum).trigger('change');

$('#button').attr('disabled', true);
$(document).on('change keyup blur', '#first', function () {
    var second = $('#second').val();
    if ($(this).val() != '') {
        sum = parseFloat($(this).val()) + parseFloat(second);
        $('#second').val(sum).trigger('change');
    }
});
$("#second").on('change', function () {
    var first = $("#first").val();
    var second = $(this).val();
    var third = $('#third').val();
    if (second == third) {
        $('#button').attr('disabled', false);
    } else {
        $('#button').attr('disabled', true);
    }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>


<input type="number" id="first" placeholder="first">
<input type="number" id="second" value="5" readonly>
<input type="number" id="third" value="10" readonly>

<input type="button" id="button" value="button">

禁用按钮，更改输入值

2 个答案: