定义file input

<div class="inputFileWrapper">
         <label for="inputFile">
             <input type="file" id="inputFile"/>
            <span class="custorm-style">
             <span class="left-button">上传头像</span>
             <span class="right-text" id="rightText"></span>
            </span>
         </label>
    </div>

 .inputFileWrapper label{
            display: block;
            float: left;
            position: relative;
        }
        .inputFileWrapper input[type="file"]{
            position: absolute;
            width: 1px;
            height: 1px;
            clip:rect(0,0,0,0);
        }
        .inputFileWrapper .custorm-style{
            display: block;
            width: 390px;
            height: 50px;
        }
        .inputFileWrapper .custorm-style .left-button{
            width: 80px;
            line-height: 50px;
            background: #008ac7;
            color: #fff;
            display: block;
            text-align: center;
            float: left;
        }
        .inputFileWrapper .custorm-style .right-text{
            width: 300px;
            height: 40px;
            line-height: 50px;
            display: block;
            float: right;
            padding: 4px;
            border: 1px solid #008ac7;
            overflow: hidden;
            -ms-text-overflow: ellipsis;
            text-overflow: ellipsis;
            white-space: nowrap;
        }

<script src="js/jquery-1.11.1.min.js"></script>
<script>
         var fileBtn = $("input[type=file]");
         fileBtn.on("change", function(){
                 var index = $(this).val().lastIndexOf("\\");
                 var sFileName = $(this).val().substr((index+1));
                 $("#rightText").html(sFileName);
             });
</script>

示例：

自定义input file 的样式，

//.val()取的值是d:/userAdmin/uploads/20120515_115146.jpg; .lastIndexOf("\\")从零开始，最后一个\\的位置，所以下面要+1

//substr() 方法可在字符串中抽取从 start 下标开始的指定数目的字符,.substr(start,length)