jquey实现放大镜功能

(function ($) {
    $.fn.imagezoom = function (options) {
        var settings = {
            xzoom: 220,
            yzoom: 220,
            offset: 10,
            position: "BTR",
            preload: 1,
            scale:1
        };
        if (options) {
            $.extend(settings, options);
        }
        var noalt = ‘‘,iTop,iLeft,iWidth,iHeight;
        var self = this;
        return self.each(function () {
            self.imagezoom = true;
            var _this = this;
            var explorer = navigator.userAgent;
            var mouseAdd = "mousewheel";
            if (explorer.indexOf("Firefox") >= 0) {
                mouseAdd = "DOMMouseScroll";
            }
            $("body").off(mouseAdd).on(mouseAdd, "div.zoomMask", function (ev) {
                var $this = $(this);
                var imgWid = $("div.zoomDiv>img").width();
                var zoom = ev.originalEvent.deltaY || (ev.originalEvent.detail > 0 ? ev.originalEvent.detail + 97 : ev.originalEvent.detail-97);
                if ($this.width() > iWidth && zoom > 0) {
                    return;
                }
                $("div.zoomDiv>img").css({ width: imgWid - zoom, height: "auto" });
                var mouseWheel = {
                    x: ev.originalEvent.clientX,
                    y: ev.originalEvent.clientY
                };
                var bigwidth = $(".bigimg").get(0).offsetWidth,
                    bigheight = $(".bigimg").get(0).offsetHeight,
                    scalex = (bigwidth / iWidth),
                    scaley = (bigheight / iHeight),
                    xpos = mouse.x - $this.width() / 2,
                    ypos = mouse.y - $this.height() / 2;
                $this.width((settings.xzoom) / scalex);
                $this.height((settings.yzoom) / scaley);
                xpos = (mouseWheel.x - $this.width() / 2 < iLeft) ? iLeft : (mouseWheel.x + $this.width() / 2 > iWidth + iLeft) ? (iWidth + iLeft - $this.width()) : xpos;
                ypos = (mouseWheel.y - $this.height() / 2 < iTop) ? iTop : (mouseWheel.y + $this.height() / 2 > iHeight + iTop) ? (iHeight + iTop - $this.height()) : ypos;
                $this.css({
                    top: ypos + $(document).scrollTop(),
                    left: xpos
                });
                var xposs = mouseWheel.x - $this.width() / 2 - iLeft,
                    yposs = mouseWheel.y - $this.height() / 2 - iTop;

                $("div.zoomDiv").scrollLeft(xposs * scalex);
                $("div.zoomDiv").scrollTop(yposs * scaley);
                //$("div.zoomDiv>img").css({ left: "-" + xposs * scalex + "px", top: "-" + yposs * scaley + "px" });
                ev.preventDefault();
            });

            $(this).on("mouseover", function (ev) {
                var imageLeft = $(this).offset().left;
                var imageTop = $(this).offset().top - $(document).scrollTop();
                var imageWidth = $(this).get(0).offsetWidth;
                var imageHeight = $(this).get(0).offsetHeight;
                iTop = imageTop, iLeft = imageLeft, iWidth = imageWidth, iHeight = imageHeight;
                var boxLeft = $(this).parent().offset().left;
                var boxTop = $(this).parent().offset().top;
                var boxWidth = $(this).parent().width();
                var boxHeight = $(this).parent().height();
                noalt = $(this).attr("alt");
                var bigimage = $(this).attr("rel");
                $(this).attr("alt", ‘‘);
                var Img = new Image();
                Img.src = $(this).attr("src");
                Img.onload = function () {
                    $("div.zoomDiv>img").css({ width: this.width * settings.scale, height: this.height * settings.scale });
                };
                if ($("div.zoomDiv").length == 0) {
                    $(document.body).append("<div class=‘zoomDiv‘ style=‘border-radius:25px;‘><img style=‘position:absolute;top:0;left:0;‘ class=‘bigimg‘ src=‘" + bigimage + "‘ onerror=‘citms.nofind();‘ /></div><div class=‘zoomMask‘> </div>");//放大镜框及遮罩
                } else {
                    $("div.zoomDiv>img").attr("src", $(this).attr("src"));
                }
                $("div.zoomDiv").width(settings.xzoom);
                $("div.zoomDiv").height(settings.yzoom);
                $("div.zoomDiv").show();
                $("div.zoomMask").show();
                $(this).css(‘cursor‘, ‘crosshair‘);
                $(document.body).off("mousemove").on("mousemove", function (e) {
                    if ($("div.zoomDiv").length == 0) {
                        $(document.body).append("<div class=‘zoomDiv‘ style=‘border-radius:25px;‘><img style=‘position:absolute;top:0;left:0;‘ class=‘bigimg‘ src=‘" + bigimage + "‘ onerror=‘citms.nofind();‘ /></div><div class=‘zoomMask‘> </div>");//放大镜框及遮罩
                    }
                    var ePageX = e.pageX + 10, ePageY = e.pageY + 10, ceiTop = 0;
                    if (settings.position == "BTR") {
                        leftpos = $("div.zoomMask").position().left + $("div.zoomMask").width() + 10;
                        ceiTop = $("div.zoomMask").position().top;
                        if ($(document).find(".layout-updown").length == 0) {
                            if (ePageY + settings.yzoom + 10 > $(document.body).height()) {
                                ceiTop = ePageY - settings.yzoom - 10
                            }
                        } else {
                            if (ePageY + settings.yzoom + 10 > $(".punishEditLeft").height()) {
                                ceiTop = ePageY - settings.yzoom - 10
                            }
                        }

                        if (ePageX + settings.xzoom + 10 > $(document.body).width() - 300) {
                            leftpos = ePageX - settings.xzoom - 20 - ($("div.zoomMask").width() / 2)
                        }

                        if ((ePageX - settings.xzoom) / 2 < $("div.zoomMask").width() / 2) {
                            leftpos = ePageX + ($("div.zoomMask").width() / 2) ;
                            if (ePageX < $("div.zoomMask").width() / 2) {
                                leftpos = $("div.zoomMask").width() + 10;
                            }
                        }
                        if ($(document.body).width() - ePageX < ($("div.zoomMask").width() / 2)) {
                            leftpos = $(document.body).width() - $("div.zoomMask").width() - $("div.zoomDiv").width() - 20
                        }
                    } else {
                        leftpos = imageLeft - settings.xzoom - settings.offset;
                        if (leftpos < 0) {
                            leftpos = imageLeft + imageWidth + settings.offset
                        }
                        ceiTop = boxTop
                    }

                    $("div.zoomDiv").css({ top: ceiTop >= 0?ceiTop:0, left: leftpos });
                    mouse = {
                        x: e.originalEvent.clientX,
                        y: e.originalEvent.clientY
                    };
                    if (mouse.x < parseInt(imageLeft) || mouse.x > Math.round(imageLeft + imageWidth) || mouse.y < parseInt(imageTop) || mouse.y > Math.round(imageTop + imageHeight)) {
                        mouseOutImage();
                        return;
                    }
                    var bigwidth = 0;
                    var bigheight = 0;
                    if ($(".bigimg").get(0)) {
                        bigwidth = $(".bigimg").get(0).offsetWidth;
                        bigheight = $(".bigimg").get(0).offsetHeight;
                    }
                    var scaley = ‘x‘;
                    var scalex = ‘y‘;
                    if (isNaN(scalex) | isNaN(scaley)) {
                        var scalex = (bigwidth / imageWidth);
                        var scaley = (bigheight / imageHeight);
                        $("div.zoomMask").width((settings.xzoom) / scalex);
                        $("div.zoomMask").height((settings.yzoom) / scaley);
                        $("div.zoomMask").css(‘visibility‘, ‘visible‘);
                    }
                    xpos = mouse.x - $("div.zoomMask").width() / 2;
                    ypos = mouse.y - $("div.zoomMask").height() / 2;
                    xposs = mouse.x - $("div.zoomMask").width() / 2 - imageLeft;
                    yposs = mouse.y - $("div.zoomMask").height() / 2 - imageTop;
                    xpos = (mouse.x - $("div.zoomMask").width() / 2 < imageLeft) ? imageLeft : (mouse.x + $("div.zoomMask").width() / 2 > imageWidth + imageLeft) ? (imageWidth + imageLeft - $("div.zoomMask").width()) : xpos;
                    ypos = (mouse.y - $("div.zoomMask").height() / 2 < imageTop) ? imageTop : (mouse.y + $("div.zoomMask").height() / 2 > imageHeight + imageTop) ? (imageHeight + imageTop - $("div.zoomMask").height()) : ypos;
                    $("div.zoomMask").css({
                        top: ypos + $(document).scrollTop(),
                        left: xpos
                    });
                    $("div.zoomDiv").scrollLeft(xposs * scalex);
                    $("div.zoomDiv").scrollTop(yposs * scaley);
                    //$("div.zoomDiv").get(0).scrollTop = yposs * scaley;
                    //var MaskLeft = -xposs * scalex;
                    //console.log(-xposs * scalex + "&&&" + -yposs * scaley);
                    //if (-xposs * scalex)
                    //$("div.zoomDiv>img").css({ left: -xposs * scalex > 0 ? 0 : -xposs * scalex, top: -yposs * scaley > 0 ? 0 : -yposs * scaley });
                });
            });
        });

        var count = 0;
        function mouseOutImage() {
            $(self).attr("alt", noalt);
            $(document.body).unbind("mousemove");
            $("div.zoomMask").hide();
            $("div.zoomDiv").hide();
            mouseImg = null;
        }
        if (settings.preload) {
            $(‘body‘).append("<div style=‘display:none;‘ class=‘jqPreload" + count + "‘></div>");
            $(this).each(function () {
                var imagetopreload = $(this).attr("rel");
                var content = jQuery(‘div.jqPreload‘ + count + ‘‘).html();
                jQuery(‘div.jqPreload‘ + count + ‘‘).html(content + ‘<img src=\"‘ + imagetopreload + ‘\">‘);
            });
        }
    }
})(jQuery);

function MouseEvent(e) {
    this.x = e.pageX;
    this.y = e.pageY;
}

记录下

原文地址：https://www.cnblogs.com/xiami2104/p/11826712.html