自己写的jQuery放大镜插件效果(二)(采用只有一张图片的思路)

废话不多说,先看效果图,和上一章节用的是同一个小图片:

这个方法实现的放大有个弊端就是放大倍数设置的过大的话,会带来图片上的模糊.但是图片加载的话要比使用2张图片加载的快很多

插件代码:

 ; (function ($) {
            $.fn.gysFdj = function (options) {
                var defaluts = { 
                    cameraW: 100, //镜头宽度
                    cameraH: 100, //镜头高度
                    pointBjColor: "#000", //镜头的背景颜色
                    pointOpacity: 0.6, //镜头的透明度
                    zoomPos: 10, //放大框距离源框的位置                
                    zoom: 2//放大倍数
                };
                options = $.extend(defaluts, options);
                var obj = $(this);               
                obj.addClass("gysFdjOrigin");
                var objOriImg=$("img",obj);
                var objOriImgW=objOriImg.width();
                var objOriImgH=objOriImg.height();                
                var fdCount = $(".gysFdjOrigin").length;
                var fdAttr = "fd"; //属性变量
                obj.attr(fdAttr, fdCount); //添加属性
                var offset = obj.offset();
                var objLeft = offset.left; //对象left                
                var objTop = offset.top; //对象top
                var objWidth = obj.width(); //对象宽度
                var objHeight = obj.height(); //对象高度              
                //镜头相对box的活动范围

                var cameraMaxLeft = objWidth + objLeft - options.cameraW; //最大左范围
                var cameraMaxTop = objHeight + objTop - options.cameraH; //最大下范围

                var imgStr = obj.html();
                var html = "";
                html += "<div style='left:" + (objLeft + objWidth + options.zoomPos) + "px; top:" + objTop + "px;display:none; position:absolute;" + (options.cameraW * options.zoom) + "px;height:" + (options.cameraH* options.zoom) + "px;overflow:hidden;' class='gysFdjBox' " + fdAttr + "=" + fdCount + ">" + imgStr + "</div>";
                $("body").append(html);
                $("img", $(".gysFdjBox[" + fdAttr + "=" + fdCount + "]")).width(objWidth*options.zoom).height(objHeight*options.zoom);
                var objFdjcamera = null;
                if ($("#gysFdjcamera").length == 0) {
                    var pointBlock = "<div id='gysFdjcamera' style='" + options.cameraW + "px; height:" + options.cameraH + "px; background-color:" + options.pointBjColor + ";opacity:" + options.pointOpacity + ";filter:alpha(opacity="+options.pointOpacity*100+");cursor:crosshair;position:absolute;display:none;'></div>";
                $("body").append(pointBlock);                
                }
                objFdjcamera = $("#gysFdjcamera");
                var nowLeft = 0, nowTop = 0;
                obj.on("mouseover", function (event) {                   
                    objFdjcamera.show().attr(fdAttr, fdCount);                                                            
                    $(".gysFdjBox["+fdAttr+"="+fdCount+"]").show();
                    $(document).on("mousemove", function (event) {
                        var pointX = event.clientX+$(document).scrollLeft();
                        var pointY = event.clientY+$(document).scrollTop();
                        nowLeft = pointX - options.cameraW / 2;
                        nowTop = pointY - options.cameraH / 2;
                        if (nowLeft <= objLeft) { nowLeft = objLeft; }
                        else if (nowLeft >= cameraMaxLeft) { nowLeft = cameraMaxLeft; }
                        if (nowTop <= objTop) { nowTop = objTop; }
                        else if (nowTop >= cameraMaxTop) { nowTop=cameraMaxTop;}                        
                        objFdjcamera.css({ left: nowLeft + "px", top: nowTop + "px" });
                        nowLeft=(nowLeft-objLeft)*options.zoom;
                        nowTop=(nowTop-objTop)*options.zoom;                                   
                        $("img",$(".gysFdjBox[" + fdAttr + "=" + fdCount + "]")).css({ "margin-top": -nowTop + "px", "margin-left": -nowLeft + "px" });
                    });
                });
                objFdjcamera.on("mouseleave", function () {
                    $(document).off("mousemove");
                    objFdjcamera.hide();
                    $(".gysFdjBox["+fdAttr+"="+fdCount+"]").hide();
                });
            }
        })(jQuery);

CSS代码:

.test{ width:300px;height:400px; overflow:hidden;}

HTML代码:

<div class="test"><img src="../img/x.jpg"  alt="小图"/></div>

插件的调用:

$(function () {
            $(".test").gysFdj({ zoom: 2 });             3         });