如何控制jquery ui弹窗下方按钮水平居中

1、问题背景

一般情况下，jquery ui弹窗下方的按钮是居右的，但是有时系统为了达到美观统一，需要将按钮放在中间

2、问题原因

<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>如何使jquery ui弹窗下方按钮水平居中</title>
		<link rel="stylesheet" href="../js/jquery-ui-1.10.4/themes/base/jquery.ui.all.css">
		<script src="../js/jquery-ui-1.10.4/jquery-1.10.2.js"></script>
		<script src="../js/jquery-ui-1.10.4/ui/jquery-ui.js"></script>
		<style>
			.ui-progressbar {
				height: 10px;
			}
			
			#dialogFile {
				min-height: 0px !important;
			}
		</style>
		<script>
			$(function() {
				$("#dialogInfo").dialog({
					resizable: false,
					title: '新增',
					height: 500,
					 420,
					modal: true,
					buttons: {
						"关闭": function() {
							$(this).dialog("close");
						}
					}
				});

				$("#dialogFile").dialog({
					autoOpen: false,
					closeOnEscape: false,
					resizable: false,
					modal:true
				});

				$("#progressbar").progressbar({
					value: false,
					complete: function() {
						$(".ui-dialog button").last().trigger("focus");
					}
				});
			});

			function openWin(obj) {
				var fileUpload = $(obj).val();
				checkFileSize(obj);
				if(fileUpload) {
					$("#dialogFile").prev().css("display","none");
					$("#dialogFile").dialog("open");
				}
			}

			function checkFileSize(obj) 
			{
				var filePath = $(obj).val();
				var fileStart = filePath.lastIndexOf(".");
				var endFile = filePath.substring(fileStart, filePath.length).toUpperCase();
				if(endFile != ".PNG" && endFile != ".JPG" && endFile != ".GIF") 
				{
					hiAlert("文件限于png,jpg或gif格式");
					return false;
				}
			
				var img = new Image();
				img.src = filePath;
				if(img.fileSize > 0) 
				{
					if(img.fileSize > 20 * 1024 * 1024) 
					{
						hiAlert("上传的文件大小不能超过20M!");
						return false;
					}
				}
				return true;
			}
		</script>
	</head>

	<body>
		<div id="dialogInfo" title="弹窗信息">
			<input type="file" οnchange="openWin(this);" />
		</div>

		<div id="dialogFile" style="height:50px;290px;">
			<div class="progress-label" style="100%;text-align:center;">正在上传...</div>
			<div id="progressbar"></div>
		</div>
	</body>

</html>

3、解决办法

需要添加样式

<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>如何使jquery ui弹窗下方按钮水平居中</title>
		<link rel="stylesheet" href="../js/jquery-ui-1.10.4/themes/base/jquery.ui.all.css">
		<script src="../js/jquery-ui-1.10.4/jquery-1.10.2.js"></script>
		<script src="../js/jquery-ui-1.10.4/ui/jquery-ui.js"></script>
		<style>
			.ui-progressbar {
				height: 10px;
			}
			
			#dialogFile {
				min-height: 0px !important;
			}
			.ui-dialog .ui-dialog-buttonpane .ui-dialog-buttonset{
				text-align: center;
				float: none;
			}
		</style>
		<script>
			$(function() {
				$("#dialogInfo").dialog({
					resizable: false,
					title: '新增',
					height: 500,
					 420,
					modal: true,
					buttons: {
						"关闭": function() {
							$(this).dialog("close");
						}
					}
				});

				$("#dialogFile").dialog({
					autoOpen: false,
					closeOnEscape: false,
					resizable: false,
					modal:true
				});

				$("#progressbar").progressbar({
					value: false,
					complete: function() {
						$(".ui-dialog button").last().trigger("focus");
					}
				});
			});

			function openWin(obj) {
				var fileUpload = $(obj).val();
				checkFileSize(obj);
				if(fileUpload) {
					$("#dialogFile").prev().css("display","none");
					$("#dialogFile").dialog("open");
				}
			}

			function checkFileSize(obj) 
			{
				var filePath = $(obj).val();
				var fileStart = filePath.lastIndexOf(".");
				var endFile = filePath.substring(fileStart, filePath.length).toUpperCase();
				if(endFile != ".PNG" && endFile != ".JPG" && endFile != ".GIF") 
				{
					hiAlert("文件限于png,jpg或gif格式");
					return false;
				}
			
				var img = new Image();
				img.src = filePath;
				if(img.fileSize > 0) 
				{
					if(img.fileSize > 20 * 1024 * 1024) 
					{
						hiAlert("上传的文件大小不能超过20M!");
						return false;
					}
				}
				return true;
			}
		</script>
	</head>

	<body>
		<div id="dialogInfo" title="弹窗信息">
			<input type="file" οnchange="openWin(this);" />
		</div>

		<div id="dialogFile" style="height:50px;290px;">
			<div class="progress-label" style="100%;text-align:center;">正在上传...</div>
			<div id="progressbar"></div>
		</div>
	</body>

</html>

.ui-dialog .ui-dialog-buttonpane .ui-dialog-buttonset{
	text-align: center;
	float: none;
}