Bootstrap 3文本中心不與行

Question

我使用Bootstrap 3.我使用兩行像col-md-4和col-md-2行內。現在我正在嘗試將兩列中間的列居中。我已使用text-left作爲col-md-2，因爲其中的按鈕需要左對齊。我用以下代碼來居中列，但它不適合我。

<div class="jumbotron"> 
    <div class="row text-center"> 
     <div class="col-md-4"> 
      <div class="input-group input-group-lg"> 
       <div class="input-group-btn text-left"> 
        <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">option 1<span class="caret"></span></button> 
        <ul class="dropdown-menu"> 
         <li><a href="#">option 1</a></li> 
         <li><a href="#">option 2</a></li> 
         <li><a href="#">option 3</a></li> 
        </ul> 
       </div><!-- /btn-group --> 
       <input type="text" class="form-control"> 
      </div><!-- /input-group --> 
     </div> 
     <div class="col-md-2 text-left"> 
      <button type="button" class="btn btn-default btn-lg"> Search <span class="glyphicon glyphicon-search"></span></button> 
     </div> 
    </div><!-- /row --> 
</div> 

Answer 1

<div class="jumbotron"> 
<div class="row"> 
    <div class="col-md-4 col-md-offset-3"> //The one i added 
     <div class="input-group input-group-lg"> 
      <div class="input-group-btn text-left"> 
       <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">option 1<span class="caret"></span></button> 
       <ul class="dropdown-menu"> 
        <li><a href="#">option 1</a></li> 
        <li><a href="#">option 2</a></li> 
        <li><a href="#">option 3</a></li> 
       </ul> 
      </div><!-- /btn-group --> 
      <input type="text" class="form-control"> 
     </div><!-- /input-group --> 
    </div> 
    <div class="col-md-2 text-left"> 
     <button type="button" class="btn btn-default btn-lg"> Search <span class="glyphicon glyphicon-search"></span></button> 
    </div> 
</div><!-- /row --> 

希望這Bootply幫助！也看看這個wiki。