Question

与标题相比，我的实际问题相当复杂。我是javascript和jquery的新手所以请耐心等待。

我会觉得你在阅读我的问题之前先运行这段代码，这样你才能理解我想要做的事情。

<html>
<head>
<script type="text/javascript" src="jquery1.6.4min.js"></script>
<script type="text/javascript" > 
var selectedAddFootballPlayerId = '';
var selectedAddFootballPlayerName = '';
var selectedRemoveFootballPlayerId = '';
var selectedRemoveFootballPlayerName = '';

$(document).ready(function() {
 $('#listboxFootballPlayers option').click(function() {
  selectedAddFootballPlayerId = $(this).attr('value');
  selectedAddFootballPlayerName = $(this).text();
 });

 $('#selectedFootballPlayers option').click(function() {
  selectedRemoveFootballPlayerId = $(this).attr('value');
  selectedRemoveFootballPlayerName = $(this).text();
 });

 $('input#btnAddFootballPlayerToList').click(function() {
  if (selectedAddFootballPlayerId == '') {
   alert("Select a football player to be added from the list.");
  } else {
   var option = new Option(selectedAddFootballPlayerName , selectedAddFootballPlayerId);
   $(option).html(selectedAddFootballPlayerName); 
   $('#selectedFootballPlayers').append(option);
   selectedAddFootballPlayerId = '';
   selectedAddFootballPlayerName = '';
  }
 });

 $('input#btnRemoveFootballPlayerFromList').click(function() {
  if (selectedRemoveFootballPlayerId == '') {
   alert("Select a football player to be removed from the list.");
  } else {
   var option = new Option(selectedRemoveFootballPlayerName , selectedRemoveFootballPlayerId);
   $(option).html(selectedRemoveFootballPlayerName); 
   $('#listboxFootballPlayers').append(option);
   selectedRemoveFootballPlayerId = '';
   selectedRemoveFootballPlayerName = '';
  }
 });
});
</script>
</head>
<body>
<table>
 <tr>
  <td>
   <select id="listboxFootballPlayers" size="5" multiple="multiple" style="width: 200px;">
    <option value="l1">Cristiano Ronaldo</option>
    <option value="l2">Ricardo Kaka</option>
    <option value="l3">Lionel Messi</option>
    <option value="l4">Gerd Muller</option>
    <option value="l5">Johan Crujjf</option>
    <option value="l6">Franz Beckenbauer</option>
    <option value="l7">David Beckham</option>
   </select>
  </td>

  <td>
   <table>
    <tr><td><input type="button" id="btnAddFootballPlayerToList" value="->" /> </td></tr>
    <tr><td><input type="button" id="btnRemoveFootballPlayerFromList" value="<-" /></td></tr>
   </table>
  </td>

  <td>
   <select id="selectedFootballPlayers" size="5" multiple="multiple" style="width: 200px;"></select>
  </td>
 </tr>
 </table>
 </body>
 </html>

在开始提出问题之前，请注意：

#listboxFootballPlayers - 左侧的列表框
#selectedFootballPlayers - 右侧的列表框

我有两个问题：

1.。）点击#listboxFootballPlayers按钮后，如何从->删除所选的项目/选项。

2。）为什么当我从<-选择一个项目/选项后点击#selectedFootballPlayers时，它会给我一条消息Select a football player to be removed from the list.在我看来它并不是' t为变量selectedRemoveFootballPlayerId分配值。

请问我是否有些问题不明确。请帮忙。非常感谢。

这是jsfiddle链接：http://jsfiddle.net/7vspM/

Answer 1

$(document).ready(function() {
    $('#listboxFootballPlayers option').click(function() {
        selectedAddFootballPlayerId = $(this).attr('value');
        selectedAddFootballPlayerName = $(this).text();
    });
    $('#selectedFootballPlayers option').live('click',  // `live()` event for `option` bcoz, option in this select will  
                                                        // create after DOM ready
    function() {
        selectedRemoveFootballPlayerId = $(this).attr('value');
        selectedRemoveFootballPlayerName = $(this).text();
    });
    $('input#btnAddFootballPlayerToList').click(function() {
        if (selectedAddFootballPlayerId == '') {
            alert("Select a football player to be added from the list.");
        } else {
            var option = new Option(selectedAddFootballPlayerName, selectedAddFootballPlayerId);
            $(option).html(selectedAddFootballPlayerName);
            $('#selectedFootballPlayers').append(option);
            $('#listboxFootballPlayers option:selected').remove();  // remove selected option
            selectedAddFootballPlayerId = '';
            selectedAddFootballPlayerName = '';
        }
    });
    $('input#btnRemoveFootballPlayerFromList').click(function() {
        if (selectedRemoveFootballPlayerId == '') {
            alert("Select a football player to be removed from the list.");
        } else {
            var option = new Option(selectedRemoveFootballPlayerName, selectedRemoveFootballPlayerId);
            $(option).html(selectedRemoveFootballPlayerName);
            $('#selectedFootballPlayers option:selected').remove(); // remove selected option
            $('#listboxFootballPlayers').append(option);
            selectedRemoveFootballPlayerId = '';
            selectedRemoveFootballPlayerName = '';
        }
    });
});

Answer 2

关于2）：

问题是您在创建要分配的元素之前分配了单击功能。当您创建选项时，您应该改为分配它，如下所示：

$(option).click(function() {
 selectedRemoveFootballPlayerId = $(this).attr('value');
 selectedRemoveFootballPlayerName = $(this).text();
});

Answer 3

关于问题一，简单地将选定的选项元素从一个列表移动到另一个列表会更容易一些：

$('#listboxFootballPlayers option:selected').appendTo('#selectedFootballPlayers');

我已经注释掉JS Fiddle demo中似乎不需要的行。

至于你的第二个问题，我改写了if / else声明：

$('input#btnRemoveFootballPlayerFromList').click(function() {
    if (!$('#selectedFootballPlayers option:selected')){
        alert("First select a player to remove.");
    }
    else {
        $('#selectedFootballPlayers option:selected').appendTo('#listboxFootballPlayers ');
    }
});

JS Fiddle demo

参考文献：

:selected。
appendTo()。

jquery - 如何从html选择中删除选定的选项？

3 个答案: