jquery圖片預覽插件實現(xiàn)方法詳解

2019-11-19 11:10:16

字體：大中小

來源：轉(zhuǎn)載

供稿：網(wǎng)友

一、需求說明

效果如圖：

二、代碼實現(xiàn)

項目結構如圖：

example.html

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>LIGHTBOX EXAMPLE</title><script type="text/javascript" src="http://code.jquery.com/jquery-1.8.3.js" ></script><script type="text/javascript" src="http://code.jquery.com/ui/1.10.4/jquery-ui.js"></script><script type="text/javascript" src="js/jquery-mousewheel.js" ></script><script type="text/javascript" src="js/mylightbox.js" ></script><script type="text/javascript"> $(function(){ // 寫法一： /*LightBox.init({ imgObj : $(".imgPreview"), config : { boxHeight : 300, boxWidth : 500 } });*/ // 寫法二： $(".imgPreview").lightbox({ boxHeight : 300, boxWidth : 500 }); });</script> <link rel="stylesheet" href="css/mylightbox.css" rel="external nofollow" /><link rel="stylesheet"  /></head> <body> <img id="lightImgaa" class="imgPreview" src="images/1.png"/> <img id="lightImgbb" class="imgPreview" src="images/2.png"/></body> </html>

mylightbox.css

.white_content {  display: none;  position: absolute; width: 800px; height: 600px; /*padding: 6px 16px;*/ padding: 0; border: 3px solid rgb(252,252,252, 0.2);  background-color: #f5f6f7;  z-index:1002;  overflow: hidden;}.white_content .con { width: 800px; height: 600px;}.black_overlay {  display: none;  position: absolute;  top: 0%;  left: 0%;  width: 100%;  height: 100%;  background-color:#777777; z-index:1001;  -moz-opacity: 0.8;  opacity:.80;  filter: alpha(opacity=80); } .white_content .close { position: relative; float:right;  clear:both;  width:100%;  text-align:right;  margin:0; z-index: 10; height: 20px; line-height: 20px; background: white;} .white_content .close a {  color:#333;  text-decoration:none;  font-size:14px;  font-weight:700 }

jquery-mousewheel.js（兼容鼠標滾輪事件的一個插件）

mylightbox.js

(function($){ var LightBox = function(lightbox) {  var _this_ = this; // 保存單個lightbox組件 this.lightbox = lightbox; // 默認配置參數(shù) this.config = { // 彈框的默認高度 "boxHeight" : 600, // 彈框的默認寬度 "boxWidth" : 800, // 頁面顯示的縮略圖默認高度 "thumbnailWidth" : 80, // 頁面顯示的縮略圖默認寬度 "thumbnailHeight" : 80 };  var userConfig = lightbox.config; if (userConfig) { // 如果傳入了用戶設置，則使用用戶設置；否則使用默認配置 $.extend(this.config, userConfig); }  var imgObj = lightbox.imgObj; // 需要有圖片預覽功能的img對象（jquery對象） imgObj.width(this.config.thumbnailWidth).height(this.config.thumbnailHeight); // 設置縮略圖大小 // 設置圖片點擊后顯示預覽圖 imgObj.click(function() { _this_.invoke($(this), _this_.config); }); };  LightBox.prototype = {  // 事件驅(qū)動方法 invoke : function(imgObj, config) { var _this_ = this; // 存放圖片信息的對象  this.imgInfo = this.getImgInfo(imgObj[0].src, config); var promptHtml = '<div><div id="light" class="white_content">' + '<div class="close"><a class="removePrompt" href="javascript:void(0)" rel="external nofollow" rel="external nofollow" rel="external nofollow" >關閉</a> <a class="resetPosition" href="javascript:void(0)" rel="external nofollow" rel="external nofollow" rel="external nofollow" >重置</a>' + ' <a class="downloadImg" href="javascript:void(0)" rel="external nofollow" rel="external nofollow" rel="external nofollow" >下載</a></div>' + '<div class="con"></div></div>' + '<div id="fade" class="black_overlay"></div></div>';  var imgHtml = '<img id="lightImg" class="ui-content" src="' + this.imgInfo.imgPath + '"/>'; var $imgHtml = $(imgHtml).width(this.imgInfo.imgActualWidth).height(this.imgInfo.imgActualHeight); var $promptHtml = $(promptHtml);  var $whiteContent = $promptHtml.find(".white_content"); var $con = $promptHtml.find(".con"); // 設置自定義的彈框高寬 $whiteContent.width(config.boxWidth).height(config.boxHeight); $con.width(config.boxWidth).height(config.boxHeight); $imgHtml.appendTo($con);  var $body = $("body"); $promptHtml.appendTo($body);  // 設置提示框的樣式 var returnData = this.promptPosition($promptHtml); this.imgInfo.imgOriginTop = returnData.imgOriginTop; this.imgInfo.imgOriginLeft = returnData.imgOriginLeft;  // 綁定事件 $promptHtml.find(".resetPosition").off("click").on("click", function() { // 重置按鈕 _this_.revertImg($promptHtml, _this_.imgInfo); }); $promptHtml.find(".removePrompt").off("click").on("click", function() { // 關閉按鈕 $promptHtml.remove(); }); $promptHtml.find(".downloadImg").off("click").on("click", function() { // 下載按鈕 _this_.downloadImg(_this_.imgInfo.imgPath); });  this.showPrompt($promptHtml); },  // 顯示提示框 showPrompt : function(promptObject) { var $whiteContent = promptObject.find(".white_content"); var $blackOverlay = promptObject.find(".black_overlay"); $whiteContent.show(); $blackOverlay.show(); },  // 對需要顯示的提示框的樣式進行初始化操作 promptPosition : function(promptObject, imgActualHeight, imgActualWidth) {  var _this_ = this;  // 設置提示框水平垂直居中 var $whiteContent = promptObject.find(".white_content"); var $con = $whiteContent.find(".con"); // 存放圖片內(nèi)容區(qū) var $close = $whiteContent.find(".close"); // 存放“關閉，重置”按鈕區(qū)  var leftDistance = ($(window).width() - $whiteContent.outerWidth(false)) / 2; var topDistance = ($(window).height() - $whiteContent.outerHeight(false)) / 2; $whiteContent.css({"left":leftDistance,"top":topDistance});  // 添加在div范圍內(nèi)的鼠標滾輪事件 窗口滾動  // 鼠標滾動  var $lightImg = $whiteContent.find(".ui-content"); $whiteContent.on("mousewheel", function(event, delta){ var imgWidth = $lightImg.width() * (1 + 0.1 * delta); var imgHeight = $lightImg.height() * (1 + 0.1 * delta); $lightImg.width(imgWidth).height(imgHeight); _this_.setImgCenterPosition($lightImg, $close, $con); });  // 設置待顯示圖片在提示框居中 var data = this.setImgCenterPosition($lightImg, $close, $con);  // 設置圖片可以拖拽 $lightImg.draggable({scroll: true});  // 記錄圖片的初始位置 var returnObj = new Object(); returnObj.imgOriginTop = data.top; returnObj.imgOriginLeft = data.left; return returnObj; },  // 設置圖片在父容器中水平垂直居中顯示 setImgCenterPosition : function(imgObj, closeObj, parentObj) { var imgOriginTop = (parentObj.outerHeight() - closeObj.outerHeight() - imgObj.outerHeight())/2; var imgOriginLeft = (parentObj.outerWidth() - imgObj.outerWidth())/2; var data = {"top" : imgOriginTop, "left" : imgOriginLeft}; imgObj.css(data); return data; },  // 下載圖片 這個只能在chrome上用，firefox，IE都不行① downloadImg : function(imgPath) { var imgFileName = imgPath.substring(imgPath.lastIndexOf("/")+1); // 獲取圖片文件名 var $a = $("<a></a>").attr("href", imgPath).attr("download", imgFileName); $a[0].click(); },  // 將圖片恢復至初始大小，和原始位置 revertImg : function(promptObject, imgInfo) { var $lightImg = promptObject.find(".ui-content"); if ($lightImg.height() != imgInfo.imgActualHeight || $lightImg.width() != imgInfo.imgActualWidth || parseInt($lightImg.css("top")) != imgInfo.imgOriginTop || parseInt($lightImg.css("left")) != imgInfo.imgOriginLeft) { $lightImg.animate({ "height" : imgInfo.imgActualHeight, "width" : imgInfo.imgActualWidth,  "top": imgInfo.imgOriginTop,  "left": imgInfo.imgOriginLeft }); } },  // 獲取圖片信息 getImgInfo : function(imgPath, config) { // 獲取顯示彈框的寬高 var boxHeight = config.boxHeight; var boxWidth = config.boxWidth;  var imgObj = $("<img/>", {"src" : imgPath})[0];  // 獲取圖片的真實寬高 var imgRealHeight = imgObj.height; var imgRealWidth = imgObj.width;  // 計算圖片適應提示框大小后呈現(xiàn)的寬高 var imgActualHeight; var imgActualWidth; if (imgRealHeight / imgRealWidth >= boxHeight / boxWidth) { imgActualHeight = imgRealHeight > boxHeight ? boxHeight : imgRealHeight; imgActualWidth = imgActualHeight / imgRealHeight * imgRealWidth; } else { imgActualWidth = imgRealWidth > boxWidth ? boxWidth : imgRealWidth; imgActualHeight = imgActualWidth / imgRealWidth * imgRealHeight; }  var returnObj = new Object(); returnObj.imgPath = imgPath; returnObj.imgRealHeight = imgRealHeight; returnObj.imgRealWidth = imgRealWidth; returnObj.imgActualHeight = imgActualHeight; returnObj.imgActualWidth = imgActualWidth;  return returnObj; }, };  // 插件供外部調(diào)用的兩種寫法 // 方法一： LightBox.init = function(lightboxes) {  var _this_ = this; var imgObjs = lightboxes.imgObj; var config = lightboxes.config;  imgObjs.each(function() { new _this_({ imgObj : $(this), config : config }); });  }; window.LightBox = LightBox;  // 方法二：注冊成jq方法 $.fn.extend({ lightbox : function(config){ this.each(function(){ new LightBox({ imgObj : $(this), config : config }); }); return this; } });}(jQuery));

// 下載圖片這個只能在chrome上用，firefox，IE都不行①jQuery實現(xiàn)圖片下載代碼

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