测试图片居中显示_新_3中情况

var imgCenterUi = {
			init : function(arg){
				var _rule = arg.rule || 1;
				var _isTrue = arg.isTrue || false;
				var thisImgHeight,thisImgWidth,parConHeight,parConWidth,scale,parscale = '';
				if(!_isTrue){
					var parObj = $('#'+arg.parId);
					var thisObj = parObj.find('img');
					policy(thisObj);
				}else{
					$('img').each(function(e) {
					  policy($(this));
                    });	
				}
				function policy(_thisObj){
					var _thisObj = _thisObj
					thisImgHeight = _thisObj.height();
					thisImgWidth = _thisObj.width();
					_thisObj.parent().css({'position':'relative','overflow':'hidden'});//此段应该在css里边早就设置过的
                    parConHeight = _thisObj.parent().height();
				    parConWidth = _thisObj.parent().width();
					parscale =  parConWidth/parConHeight;//计算容器宽度跟高度的比例
					scale =  thisImgWidth/thisImgHeight;//计算当前图片宽度跟高度的比例
					if(_rule == 1){
						imgCenterUi.bespread(thisImgHeight,thisImgWidth,parConHeight,parConWidth,scale,parscale,_thisObj);
					}
					if(_rule == 2){
						imgCenterUi.half_bespread(thisImgHeight,thisImgWidth,parConHeight,parConWidth,scale,parscale,_thisObj);
					}
					if(_rule == 3){
						imgCenterUi.centerImg(thisImgHeight,thisImgWidth,_thisObj);
					}
				}
			},
			/*
				@铺满
			*/
			bespread : function(thisImgHeight,thisImgWidth,parConHeight,parConWidth,scale,parscale,thisObj){
				var _thisObj = thisObj;
				if(scale > parscale){
					margLeft = thisImgWidth/(thisImgHeight/parConHeight);
					_thisObj.css({'height':parConHeight,'position':'relative','left':'50%','margin-left':'-'+margLeft/2+'px'});
				}else{
					margTop = thisImgHeight/(thisImgWidth/parConWidth);
					_thisObj.css({'width':parConWidth,'position':'relative','top':'50%','margin-top':'-'+ margTop/2 +'px'});
				}
				return false;
			},
			/*
				@一半铺满
			*/
			half_bespread : function(thisImgHeight,thisImgWidth,parConHeight,parConWidth,scale,parscale,thisObj){
				var _thisObj = thisObj;
				if(scale > parscale){
					margTop = thisImgHeight/(thisImgWidth/parConWidth);
					_thisObj.css({'width':parConWidth,'position':'relative','top':'50%','margin-top':'-'+ margTop/2 +'px'});
				}else{
					margLeft = thisImgWidth/(thisImgHeight/parConHeight);
					_thisObj.css({'height':parConHeight,'position':'relative','left':'50%','margin-left':'-'+margLeft/2+'px'});
				}
				return false;
			},
			/*
				@仅仅居中展示、多余的部分隐藏、隐藏的部分应该是在css里边就做好、设置超出父容器的部分隐藏就好
			*/
			centerImg : function(thisImgHeight,thisImgWidth,thisObj){
				var _thisObj = thisObj;
				_thisObj.css({'position':'absolute','left':'50%','top':'50%','margin-left':'-'+(thisImgWidth/2)+'px','margin-top':'-'+(thisImgHeight/2)+'px'});
				return false;
			}
	}
	$(function(){
		//需要两个参数、
		arg = {
				rule:'1',//1全屏铺满不变形 2.一面铺满不变形 3.保持原形居中展示
				isTrue:false,//是否对所有img进行统一设置
				parId:'img'//如果只对某一个img处理那么需要传入他父容器的ID 
			  };
		arg2 = {
				rule:'2',//1全屏铺满不变形 2.一面铺满不变形 3.保持原形居中展示
				isTrue:false,//是否对所有img进行统一设置
				parId:'img2'//如果只对某一个img处理那么需要传入他父容器的ID 
			  };
		arg3 = {
				rule:'3',//1全屏铺满不变形 2.一面铺满不变形 3.保持原形居中展示
				isTrue:false,//是否对所有img进行统一设置
				parId:'img3'//如果只对某一个img处理那么需要传入他父容器的ID 
		 	 };
		imgCenterUi.init(arg);
		imgCenterUi.init(arg2);
		imgCenterUi.init(arg3);
		
		/*
			如果需要将所有的图片都按照一种格式、如下：
			arg = {
				rule:'1',//1全屏铺满不变形 2.一面铺满不变形 3.保持原形居中展示
				isTrue:true
		    };
			 imgCenterUi.init(arg);
		*/
	});