我需要在表格中显示特定数量的行。
从选择列表中选择一个数字时，只应显示那么多行。
答案 0 :(得分：1)
你必须包含这样的jquery函数，选择所选选项的值并根据它改变tr的可见性。
function act() {
var num = $( "#sel1 option:selected" ).text();
$('#example tr').each(function(i, row) {
if(num < 0){
$(this).css('display','none');
} else {
num = num - 1;
$(this).css('display','table-row');
}
});
}
$(function() {
act();
});
$( "#sel1" ).change(function() {
act();
});<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<body>
<div class="container">
<table id="example" class="table table-striped table-bordered" cellspacing="0" width="100%">
<thead>
<tr>
<th>Name</th>
<th>Position</th>
<th>Office</th>
<th>Age</th>
<th>Start date</th>
<th>Salary</th>
</tr>
</thead>
<tfoot>
<tr>
<th>Name</th>
<th>Position</th>
<th>Office</th>
<th>Age</th>
<th>Start date</th>
<th>Salary</th>
</tr>
</tfoot>
<tbody>
<tr>
<td>Martena Mccray</td>
<td>Post-Sales support</td>
<td>Edinburgh</td>
<td>46</td>
<td>2011/03/09</td>
<td>$324,050</td>
</tr>
<tr>
<td>Unity Butler</td>
<td>Marketing Designer</td>
<td>San Francisco</td>
<td>47</td>
<td>2009/12/09</td>
<td>$85,675</td>
</tr>
<tr>
<td>Howard Hatfield</td>
<td>Office Manager</td>
<td>San Francisco</td>
<td>51</td>
<td>2008/12/16</td>
<td>$164,500</td>
</tr>
<tr>
<td>Hope Fuentes</td>
<td>Secretary</td>
<td>San Francisco</td>
<td>41</td>
<td>2010/02/12</td>
<td>$109,850</td>
</tr>
<tr>
<td>Vivian Harrell</td>
<td>Financial Controller</td>
<td>San Francisco</td>
<td>62</td>
<td>2009/02/14</td>
<td>$452,500</td>
</tr>
<tr>
<td>Timothy Mooney</td>
<td>Office Manager</td>
<td>London</td>
<td>37</td>
<td>2008/12/11</td>
<td>$136,200</td>
</tr>
<tr>
<td>Jackson Bradshaw</td>
<td>Director</td>
<td>New York</td>
<td>65</td>
<td>2008/09/26</td>
<td>$645,750</td>
</tr>
<tr>
<td>Olivia Liang</td>
<td>Support Engineer</td>
<td>Singapore</td>
<td>64</td>
<td>2011/02/03</td>
<td>$234,500</td>
</tr>
<tr>
<td>Bruno Nash</td>
<td>Software Engineer</td>
<td>London</td>
<td>38</td>
<td>2011/05/03</td>
<td>$163,500</td>
</tr>
<tr>
<td>Sakura Yamamoto</td>
<td>Support Engineer</td>
<td>Tokyo</td>
<td>37</td>
<td>2009/08/19</td>
<td>$139,575</td>
</tr>
<tr>
<td>Thor Walton</td>
<td>Developer</td>
<td>New York</td>
<td>61</td>
<td>2013/08/11</td>
<td>$98,540</td>
</tr>
<tr>
<td>Finn Camacho</td>
<td>Support Engineer</td>
<td>San Francisco</td>
<td>47</td>
<td>2009/07/07</td>
<td>$87,500</td>
</tr>
<tr>
<td>Serge Baldwin</td>
<td>Data Coordinator</td>
<td>Singapore</td>
<td>64</td>
<td>2012/04/09</td>
<td>$138,575</td>
</tr>
<tr>
<td>Zenaida Frank</td>
<td>Software Engineer</td>
<td>New York</td>
<td>63</td>
<td>2010/01/04</td>
<td>$125,250</td>
</tr>
<tr>
<td>Zorita Serrano</td>
<td>Software Engineer</td>
<td>San Francisco</td>
<td>56</td>
<td>2012/06/01</td>
<td>$115,000</td>
</tr>
<tr>
<td>Jennifer Acosta</td>
<td>Junior Javascript Developer</td>
<td>Edinburgh</td>
<td>43</td>
<td>2013/02/01</td>
<td>$75,650</td>
</tr>
<tr>
<td>Cara Stevens</td>
<td>Sales Assistant</td>
<td>New York</td>
<td>46</td>
<td>2011/12/06</td>
<td>$145,600</td>
</tr>
<tr>
<td>Hermione Butler</td>
<td>Regional Director</td>
<td>London</td>
<td>47</td>
<td>2011/03/21</td>
<td>$356,250</td>
</tr>
<tr>
<td>Lael Greer</td>
<td>Systems Administrator</td>
<td>London</td>
<td>21</td>
<td>2009/02/27</td>
<td>$103,500</td>
</tr>
<tr>
<td>Jonas Alexander</td>
<td>Developer</td>
<td>San Francisco</td>
<td>30</td>
<td>2010/07/14</td>
<td>$86,500</td>
</tr>
<tr>
<td>Shad Decker</td>
<td>Regional Director</td>
<td>Edinburgh</td>
<td>51</td>
<td>2008/11/13</td>
<td>$183,000</td>
</tr>
<tr>
<td>Michael Bruce</td>
<td>Javascript Developer</td>
<td>Singapore</td>
<td>29</td>
<td>2011/06/27</td>
<td>$183,000</td>
</tr>
<tr>
<td>Donna Snider</td>
<td>Customer Support</td>
<td>New York</td>
<td>27</td>
<td>2011/01/25</td>
<td>$112,000</td>
</tr>
</tbody>
</table>
<form role="form">
<div class="form-group">
<label>Select Number OF Rows To Be Displayed</label>
<select class="form-control" id="sel1">
<option>5</option>
<option>10</option>
<option>15</option>
</select>
</div>
</form>
</div>
</body>
答案 1 :(得分：0)
你可以使用jQuery的：gt（）选择器在不需要循环的情况下执行此操作： https://api.jquery.com/gt-selector/
在计算行时要小心基于0的索引，因此需要num ++。
function act() {
var num = $( "#sel1 option:selected" ).text();
num++;
$("#example tr").show();
$("#example tr:gt(" + num + ")").hide();
}
$(function() {
act();
});
$( "#sel1" ).change(function() {
act();
});<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<body>
<div class="container">
<table id="example" class="table table-striped table-bordered" cellspacing="0" width="100%">
<thead>
<tr>
<th>Name</th>
<th>Position</th>
<th>Office</th>
<th>Age</th>
<th>Start date</th>
<th>Salary</th>
</tr>
</thead>
<tfoot>
<tr>
<th>Name</th>
<th>Position</th>
<th>Office</th>
<th>Age</th>
<th>Start date</th>
<th>Salary</th>
</tr>
</tfoot>
<tbody>
<tr>
<td>Martena Mccray</td>
<td>Post-Sales support</td>
<td>Edinburgh</td>
<td>46</td>
<td>2011/03/09</td>
<td>$324,050</td>
</tr>
<tr>
<td>Unity Butler</td>
<td>Marketing Designer</td>
<td>San Francisco</td>
<td>47</td>
<td>2009/12/09</td>
<td>$85,675</td>
</tr>
<tr>
<td>Howard Hatfield</td>
<td>Office Manager</td>
<td>San Francisco</td>
<td>51</td>
<td>2008/12/16</td>
<td>$164,500</td>
</tr>
<tr>
<td>Hope Fuentes</td>
<td>Secretary</td>
<td>San Francisco</td>
<td>41</td>
<td>2010/02/12</td>
<td>$109,850</td>
</tr>
<tr>
<td>Vivian Harrell</td>
<td>Financial Controller</td>
<td>San Francisco</td>
<td>62</td>
<td>2009/02/14</td>
<td>$452,500</td>
</tr>
<tr>
<td>Timothy Mooney</td>
<td>Office Manager</td>
<td>London</td>
<td>37</td>
<td>2008/12/11</td>
<td>$136,200</td>
</tr>
<tr>
<td>Jackson Bradshaw</td>
<td>Director</td>
<td>New York</td>
<td>65</td>
<td>2008/09/26</td>
<td>$645,750</td>
</tr>
<tr>
<td>Olivia Liang</td>
<td>Support Engineer</td>
<td>Singapore</td>
<td>64</td>
<td>2011/02/03</td>
<td>$234,500</td>
</tr>
<tr>
<td>Bruno Nash</td>
<td>Software Engineer</td>
<td>London</td>
<td>38</td>
<td>2011/05/03</td>
<td>$163,500</td>
</tr>
<tr>
<td>Sakura Yamamoto</td>
<td>Support Engineer</td>
<td>Tokyo</td>
<td>37</td>
<td>2009/08/19</td>
<td>$139,575</td>
</tr>
<tr>
<td>Thor Walton</td>
<td>Developer</td>
<td>New York</td>
<td>61</td>
<td>2013/08/11</td>
<td>$98,540</td>
</tr>
<tr>
<td>Finn Camacho</td>
<td>Support Engineer</td>
<td>San Francisco</td>
<td>47</td>
<td>2009/07/07</td>
<td>$87,500</td>
</tr>
<tr>
<td>Serge Baldwin</td>
<td>Data Coordinator</td>
<td>Singapore</td>
<td>64</td>
<td>2012/04/09</td>
<td>$138,575</td>
</tr>
<tr>
<td>Zenaida Frank</td>
<td>Software Engineer</td>
<td>New York</td>
<td>63</td>
<td>2010/01/04</td>
<td>$125,250</td>
</tr>
<tr>
<td>Zorita Serrano</td>
<td>Software Engineer</td>
<td>San Francisco</td>
<td>56</td>
<td>2012/06/01</td>
<td>$115,000</td>
</tr>
<tr>
<td>Jennifer Acosta</td>
<td>Junior Javascript Developer</td>
<td>Edinburgh</td>
<td>43</td>
<td>2013/02/01</td>
<td>$75,650</td>
</tr>
<tr>
<td>Cara Stevens</td>
<td>Sales Assistant</td>
<td>New York</td>
<td>46</td>
<td>2011/12/06</td>
<td>$145,600</td>
</tr>
<tr>
<td>Hermione Butler</td>
<td>Regional Director</td>
<td>London</td>
<td>47</td>
<td>2011/03/21</td>
<td>$356,250</td>
</tr>
<tr>
<td>Lael Greer</td>
<td>Systems Administrator</td>
<td>London</td>
<td>21</td>
<td>2009/02/27</td>
<td>$103,500</td>
</tr>
<tr>
<td>Jonas Alexander</td>
<td>Developer</td>
<td>San Francisco</td>
<td>30</td>
<td>2010/07/14</td>
<td>$86,500</td>
</tr>
<tr>
<td>Shad Decker</td>
<td>Regional Director</td>
<td>Edinburgh</td>
<td>51</td>
<td>2008/11/13</td>
<td>$183,000</td>
</tr>
<tr>
<td>Michael Bruce</td>
<td>Javascript Developer</td>
<td>Singapore</td>
<td>29</td>
<td>2011/06/27</td>
<td>$183,000</td>
</tr>
<tr>
<td>Donna Snider</td>
<td>Customer Support</td>
<td>New York</td>
<td>27</td>
<td>2011/01/25</td>
<td>$112,000</td>
</tr>
</tbody>
</table>
<form role="form">
<div class="form-group">
<label>Select Number OF Rows To Be Displayed</label>
<select class="form-control" id="sel1">
<option>5</option>
<option>10</option>
<option>15</option>
</select>
</div>
</form>
</div>
</body>
答案 2 :(得分：0)
使用jQuery：
$('#sel1').on('change', function() {
$("#example tbody tr").show();
$("#example tbody tr:gt("+(this.value-1)+")").hide();
});