在 Bootstrap v3.1.1 中无法将 div 居中对齐

Question

我正在使用 Bootstrap v3.1.1 并尝试将 div 对齐到中心但无法将 div 对齐到中心

这是我的页面代码，我需要将 for 置于页面中央，但无法做到这一点，谁能帮我在中央形成褐藻糖胶表格

<!DOCTYPE HTML>
<html lang="en">
    <head>
        <title>Animus A Blogging Category Flat Bootstarp Resposive Website Template | Home :: w3layouts</title>
        <link href="css/bootstrap.css" rel="stylesheet" type="text/css" media="all">
        <link href="css/style.css" rel="stylesheet" type="text/css" media="all" />
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <meta name="keywords" content="Graphic Responsive web template, Bootstrap Web Templates, Flat Web Templates, Andriod Compatible web template, 
              Smartphone Compatible web template, free webdesigns for Nokia, Samsung, LG, SonyErricsson, Motorola web design" />
    </head>
    <body>
        <div class="contact-top">
            <div class="container">
                <h2>Log in</h2>     
                <div class="contact">
                    <p></p>
                    <div class="contact-down">
                        <div class="col-md-6 contact-info" style="margin-left:auto;margin-right:auto;">
                            <form>
                                <input type="text" name="your name" placeholder="USER NAME" class="input"><br><br>
                                <input type="password" name="your email" placeholder="PASSWORD" class="input">
                                <div class="clearfix"> </div>
                                <input type="submit"value="SEND" />
                            </form>                 
                        </div>
                        <div class="clearfix"> </div>

                    </div>
                </div>  
            </div>
        </div>
    </body>
</html>

Answer 1

能否添加如下col-md-offset-3 Contact-info div

<div class="col-md-6 col-md-offset-3 contact-info">
  <form>
    <input type="text" name="your name" placeholder="USER NAME" class="input"><br><br>
    <input type="password" name="your email" placeholder="PASSWORD" class="input">
    <div class="clearfix"> </div>
   <input type="submit"value="SEND" />
  </form>                 
</div>

Answer 2

在 div 上设置宽度。

<div class="col-md-6 contact-info" style="margin-left:auto;margin-right:auto;width:600px;">

在 Bootstrap v3.1.1 中无法将 div 居中对齐

unable to align div in center in Bootstrap v3.1.1

html

css

twitter-bootstrap

twitter-bootstrap-3