我正在使用一个jQuery占位符插件(https://github.com/danielstocks/jQuery-Placeholder)。我需要在下拉菜单中更改占位符文本。但这并没有改变。代码如下:

$(function () {
    $('input[placeholder], textarea[placeholder]').placeholder();
    $('#serMemdd').change(function () {
        var k = $(this).val();
        if (k == 1) {
            $("#serMemtb").attr("placeholder", "Type a name (Lastname, Firstname)").placeholder();
        }
        else if (k == 2) {
            $("#serMemtb").attr("placeholder", "Type an ID").placeholder();
        }
        else if (k == 3) {
            $("#serMemtb").attr("placeholder", "Type a Location").placeholder();
        }
    });
});

我的Html:

<div class="filterbox">
        <select name="ddselect" id="serMemdd">
            <option value="1" selected="selected">Search by Name</option>
            <option value="2">Search by ID</option>
            <option value="3">Search by Location</option>
        </select>
        <input id="serMemtb" type="text" style="width: 490px" placeholder="Type a name    (Lastname, Firstname)" />
        <input id="seMemBut" type="button" value="Search" />
    </div>

有人能算出来吗?


当前回答

$(this).val()是一个字符串。使用parseInt($(this).val(), 10)或检查'1'。10表示以10为底。

$(function () {
    $('input[placeholder], textarea[placeholder]').blur();
    $('#serMemdd').change(function () {
        var k = $(this).val();
        if (k == '1') {
            $("#serMemtb").attr("placeholder", "Type a name (Lastname, Firstname)").blur();
        }
        else if (k == '2') {
            $("#serMemtb").attr("placeholder", "Type an ID").blur();
        }
        else if (k == '3') {
            $("#serMemtb").attr("placeholder", "Type a Location").blur();
        }
    });
});

Or

$(function () {
    $('input[placeholder], textarea[placeholder]').placeholder();
    $('#serMemdd').change(function () {
        var k = parseInt($(this).val(), 10);
        if (k == 1) {
            $("#serMemtb").attr("placeholder", "Type a name (Lastname, Firstname)").blur();
        }
        else if (k == 2) {
            $("#serMemtb").attr("placeholder", "Type an ID").blur();
        }
        else if (k == 3) {
            $("#serMemtb").attr("placeholder", "Type a Location").blur();
        }
    });
});

其他插件

ori已经让我注意到你正在使用的插件不能克服ie HTML失败。

试试这样做: http://archive.plugins.jquery.com/project/input-placeholder

其他回答

把你的第一行移到底部对我有用:http://jsfiddle.net/tcloninger/SEmNX/

$(function () {
    $('#serMemdd').change(function () {
        var k = $(this).val();
        if (k == 1) {
            $("#serMemtb").attr("placeholder", "Type a name (Lastname, Firstname)").placeholder();
        }
        else if (k == 2) {
            $("#serMemtb").attr("placeholder", "Type an ID").placeholder();
        }
        else if (k == 3) {
            $("#serMemtb").attr("placeholder", "Type a Location").placeholder();
        }
    });
    $('input[placeholder], textarea[placeholder]').placeholder();
});
$(document).ready(function(){ 
     $("input[type=search]").attr("placeholder","this is a test");
});

如果输入是在div内部,那么你可以尝试这样做:

$('#div_id input').attr("placeholder", "placeholder text");
$(document).ready(function(){ 
  $('form').find("input[type=textarea], input[type=password], textarea").each(function(ev)
  {
      if(!$(this).val()) { 
     $(this).attr("placeholder", "Type your answer here");
  }
  });
});

复制并粘贴这段代码在你的js文件,这将改变所有占位符文本从整个网站。

使用jquery更改占位符文本

试试这个

$('#selector').attr("placeholder", "Type placeholder");