Ajax等待界面美化和div永遠屏幕居中顯示

JQuery得Ajax提交數據時，爲了加強界面效果，通常會添加一個等待畫面。

CSS：

/* Ajax等待效果  */ 
.loading{  
    position: absolute;  
    /* top:50%;  
     left:50%;  */
    width:220px;   
    height:56px;   
    line-height:56px;  
    color:#fff;  
    padding-left:60px;  
    font-size:15px;  
    background: #000 url(data:image/gif;base64,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) no-repeat 10px 50%;  
    opacity: 0.7;  
    z-index:9999; /*浮動在最上層 */
    -moz-border-radius:20px;  
    -webkit-border-radius:20px;  
    border-radius:20px;  
    filter:progid:DXImageTransform.Microsoft.Alpha(opacity=70);  
}  

Ajax全局設置：

 <script type="text/javascript">
            $(document).ready(function () {
                $(document).ajaxStart(function () {
                    //  var wait = '<div class="loading" id="waitting">正在努力加載數據...</div>';
                    $('body').append('<div class="loading" id="waitting">正在努力加載數據...</div>');
                    $('body').find('#waitting').css('top', $(document).scrollTop() + $(window).height() / 2 - 28 + 'px');
                    $('body').find('#waitting').css('left', $(document).scrollLeft() + $(window).width() / 2 - 110 + 'px');
                }).ajaxStop(function () {
                    $('body').find('#waitting').remove();
                });
            });
        </script>

這裏動態添加一個div顯示狀態，並且通過js進行定位，時使其屏幕居中。

附：

   ajax提交函數：

 function submitExamPaper(paper_count, paper_score, exam_time, exam_score) {
            var token = $('#__token__').val();
            var headerView = $('#headerTitle').html();
            var contentView = $('.mainTopic').html();
            // 過濾js
            contentView = contentView.replace(/<script.*?>.*?<\/script>/ig, '');
            // 
            var params = {'tal_count': paper_count, 'tal_score': paper_score, 'exam_time': exam_time, 'exam_score': exam_score,
                'headerView': (headerView), 'contentView': (contentView), '__token__': token};
            var url = '{:url("Exam/examPaper")}';
            $.ajax({
                type: "post",
                url: url,
                //async: true,
                data: params,
                success: function (data) {
                    ajaxValue = data;
                },
                error: function (XMLHttpRequest) {
                    ajaxValue = {'status': 0, 'msg': XMLHttpRequest.statusText};
                }
            }); 
        }

  // code
            submitExamPaper('{$exam.tal_count}', '{$exam.tal_score}', useTimes, tal_score);

            var ajaxWait = window.setInterval(function () {
                if (ajaxValue !== null) {
                    window.clearInterval(ajaxWait); 
            if (ajaxValue.status === 1) {
                $('#resultPanel').modal('show');
            } else {
                Ewin.error({message: ajaxValue.msg});
            }
                }
            }, 500);

說明：

ajaxValue 爲已全局變量

由於IE在ajax同步運行時會阻塞js執行，ajaxStart會失效，所以添加一個定時器來獲取ajax返回值。

 

參見：

https://zhidao.baidu.com/question/123674913.html

https://zhidao.baidu.com/question/491929507.html