hzf1993通过本文主要向大家介绍了利用imgareaselect辅助后台实现图片上传裁剪等相关知识,希望对您有所帮助,也希望大家支持linkedu.com www.linkedu.com
因为项目当中用到图片裁剪,本来可以不用到后台进行裁剪的,但是要兼容万恶的IE浏览器,所以不得不使用后台进行裁剪。
这次使用到imgareaselect 插件获取需要裁剪区域的坐标,再由后台进行裁剪操作。先上个效果图再说
但是这里有一个坑就是上传的图片过大,可能会造成裁剪的区域跟插件中显示的不一样,所以得现在后台对云图片进行压缩在裁剪。
/** * 等比例压缩算法: * 算法思想:根据压缩基数和压缩比来压缩原图,生产一张图片效果最接近原图的缩略图 * @param srcURL 原图地址 * @param deskURL 缩略图地址 * @param comBase 压缩基数 * @param scale 压缩限制(宽/高)比例 一般用1: * 当scale>=1,缩略图height=comBase,width按原图宽高比例;若scale<1,缩略图width=comBase,height按原图宽高比例 * @throws Exception */ public static void saveMinPhoto(String srcURL, String deskURL, double comBase, double scale) throws Exception { File srcFile = new java.io.File(srcURL); String ext = srcURL.substring(srcURL.lastIndexOf(".") + 1); Image src = ImageIO.read(srcFile); int srcHeight = src.getHeight(null); int srcWidth = src.getWidth(null); int deskHeight = 0;// 缩略图高 int deskWidth = 0;// 缩略图宽 double srcScale = (double) srcHeight / srcWidth; /**缩略图宽高算法*/ if ((double) srcHeight > comBase || (double) srcWidth > comBase) { if (srcScale >= scale || 1 / srcScale > scale) { if (srcScale >= scale) { deskHeight = (int) comBase; deskWidth = srcWidth * deskHeight / srcHeight; } else { deskWidth = (int) comBase; deskHeight = srcHeight * deskWidth / srcWidth; } } else { if ((double) srcHeight > comBase) { deskHeight = (int) comBase; deskWidth = srcWidth * deskHeight / srcHeight; } else { deskWidth = (int) comBase; deskHeight = srcHeight * deskWidth / srcWidth; } } } else { deskHeight = srcHeight; deskWidth = srcWidth; } BufferedImage tag = new BufferedImage(deskWidth, deskHeight, BufferedImage.TYPE_3BYTE_BGR); tag.getGraphics().drawImage(src, 0, 0, deskWidth, deskHeight, null); //绘制缩小后的图 FileOutputStream deskImage = new FileOutputStream(deskURL); //输出到文件流 ImageIO.write(tag, ext, new File(deskURL)); deskImage.close(); }</div>
这就是压缩之后在进行裁剪了,好了上完整代码先
<!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>上传头像</title> <link rel="stylesheet" href="../../statics/css/ewt/style_1.css" rel="external nofollow" type="text/css"> <link rel="stylesheet" href="../../statics/css/ewt/style_shangchuangtouxiang.css" rel="external nofollow" > <link rel="stylesheet" type="text/css" href="../../statics/css/ewt/imgareaselect-default.css" rel="external nofollow" > <link rel="stylesheet" href="../../statics/css/ewt/style.css" rel="external nofollow" type="text/css" /> <link rel="stylesheet" href="../../statics/scripts/layer/skin/default/layer.css" rel="external nofollow" > <script src="//cdn.bootcss.com/jquery/1.11.3/jquery.min.js"></script> <script src="../../statics/scripts/include.js"></script> <script src="../../statics/scripts/template.js"></script> <script src="../../statics/scripts/layer/layer.js"></script> <script src="../../statics/scripts/cropbox.js"></script> <script src="../../statics/scripts/jquery.imgareaselect.pack.js"></script> <script src="../../statics/scripts/ajaxfileupload.js"></script> <script src="../../ewt/user/scripts/shangchuangtouxiang.js"></script> <script src="../../ewt/common/config.js"></script> </head> <body> <include src="../common/user_head.html"></include> <div class="bggg"> <div class="box"> <div class="bos"> <include src="../common/user_menu.html"></include> <div class="bos_r"> <div class="biaoti"> <h3>上传头像</h3> </div> <div style=" width:915px; height: 400; display: block; overflow: hidden; margin: 30px auto; "> <div style=" width:430px; margin:0 auto;"> <div class="frame" style="margin: 0 0.3em; width: 300px; height: 300px; float: left;"> <img id="photo" src="" style="width: 300px; height: 300px;"/> </div> <div id="preview" style="width: 100px; height: 100px; overflow: hidden; float: left;"> <img src="" style="width: 100px; height: 100px;" id="smallImage"/> </div> </div> </div> <div style=" width:425px; margin:30px auto;"> <div class="input_XZ1"> <div class="input_XZ">选择图片</div> <input id="uplodimage" class="input_style" name="uplodimage" type="file" onchange="uplodImage(this)"> </div> <input id="imgUrl" type="hidden"> <input type="button" value="上传" class="input_SC" onclick="upold();"> </div> <input type="hidden" id="x1" value="" /> <input type="hidden" id="y1" value="" /> <input type="hidden" id="x2" value="" /> <input type="hidden" id="y2" value="" /> <input type="hidden" id="w" value="" /> <input type="hidden" id="h" value="" /> </div> </div> </div> </div> <include src="../common/user_footer.html"></include> </body> </html></div>
js 代码
function preview(img, selection) { if (!selection.width || !selection.height) return; var scaleX = 100 / selection.width; var scaleY = 100 / selection.height; $('#preview img').css({ width: Math.round(scaleX * 300), height: Math.round(scaleY * 300), marginLeft: -Math.round(scaleX * selection.x1), marginTop: -Math.round(scaleY * selection.y1) }); $('#x1').val(selection.x1); $('#y1').val(selection.y1); $('#x2').val(selection.x2); $('#y2').val(selection.y2); $('#w').val(selection.width); $('#h').val(selection.height); } $(function () { }); //上传原始图片 function uplodImage(target) { if(checkImage(target)){ var url = httpUtils.rootPath+'/component/upload.do'; $.ajaxFileUpload({ url: url, //用于文件上传的服务器端请求地址 secureuri: false, //是否需要安全协议,一般设置为false fileElementId: 'uplodimage', //文件上传域的ID dataType: 'json', //返回值类型 一般设置为json success: function (data) //服务器成功响应处理函数 { var filePath = data.filePath; $('#photo').attr('src',httpUtils.rootPath+'/component/upload.do?action=download&filepath='+filePath); $('#smallImage').attr('src',httpUtils.rootPath+'/component/upload.do?action=download&filepath='+filePath); $('#imgUrl').val(filePath); $('#photo').imgAreaSelect({ aspectRatio: '1:1', x1: 50, y1: 50, x2: 241, y2: 241, handles: true, fadeSpeed: 200, onSelectChange: preview }); $('#x1').val("