本文转载自 http://www.youarebug.com/forum.php?mod=viewthread&tid=56&extra=page%3D1
我们在网页上传图片的时候,特别是上传图像等操作,需要限制用户上传图片的类型、大小、有时候还需要对图片进行剪切。这样的需求在我们工作中经常遇到。今天就来说说在web开发中,如何对上传的图片判断文件的类型、检查文件的大小、对图片进行可视化裁剪等操作。很少写帖子,有不足之处,请不吝赐教。先上图看看效果:
主要采用的技术:1、jquery.uploadify 用于图片上传 检查图片大小官网:http://www.uploadify.com/
2、imgAreaSelect 用于选择要剪切的图片区域 官网:http://odyniec.net/projects/imgareaselect/ 下载上面两个文件包待用。
步骤:
1、创建ASP.net mvc3工程 工程名为ImgUpload.
2、拷贝jquery.imgareaselect-0.9.10文件夹下面的jquery.imgareaselect.min.js文件到Scripts下面的js文件夹中。
拷贝jquery.imgareaselect-0.9.10文件夹下面的css文件夹到Content下面。
拷贝uploadify文件夹下面的jquery.uploadify.min.js文件到Scripts下面的js文件夹中。
拷贝uploadify文件夹下面的uploadify.swf文件到Content下面的swf文件夹中。
如果上面没有文件夹请自己新建。
现在的文件结构如下
- $(function () {
- $('#fileToUpload').uploadify({
- 'progressData': 'speed',
- 'multi': false,
- 'method': 'post',
- 'queueID': 'some_file_queue',
- 'fileSizeLimit': '1000k',
- 'fileTypeDesc': 'Image Files',
- 'fileTypeExts': '*.gif; *.jpg; *.png',
- 'swf': '/Content/swf/uploadify.swf',
- 'uploader': '/User/UploadImg',
- 'onUploadStart': function (file) {
- $('#fileToUpload').uploadify('disable', true)
- }, 'onUploadComplete': function (file) {
- $('#fileToUpload').uploadify('disable', false)
- }, 'onUploadSuccess': function (file, data, response) {
- $('#fileToUpload').uploadify('disable', false)
- $("#PreviewImg").attr("src", "/Content/TempImg/" + data);
- $("#PreviewImg").attr("data-value", data);
- }
- // Put your options here
- });
- $('#PreviewImg').imgAreaSelect({
- handles: true,
- onSelectEnd: preview
- });
- $("#savebtn").click(function () {
- $.ajax({
- url: "/User/SaveHeaderImg?fileName=" + $("#preview_img").attr("src"),
- dataType: "text",
- success: function (json) {
- $("#tiebaSaveOkMsg").attr("style", "font-size: 110%; font-weight: bold; padding-left: 0.1em;display: block;");
- $("#savebtn_swap").attr("style", "display:none");
- }
- });
- });
- });
- function preview(img, selection) {
- if (!selection.width || !selection.height)
- return;
- var previewImg = $("#PreviewImg").attr("src");
- if ('/Content/Header/defaut.png' == previewImg) return;
- $.ajax({
- url: "/User/CutoutImg?fileName=" + previewImg + "&top=" + selection.y1 + "&left=" + selection.x1 + "&width=" + selection.width + "&height=" + selection.height,
- dataType: "text",
- success: function (json) {
- $("#preview_img").attr("src", "/Content/TempImg/" + json);
- $("#savebtn_swap").attr("style", "display:block;text-align:center; ");
- $("#tiebaSaveOkMsg").attr("style", "display:none");
- }
- });
- }
4、创建Home控制器。添加ImgUpload方法以及视图。
ImgUpload视图的代码如下:
- @{
- ViewBag.Title = "HeaderImgPage";
- Layout = null;
- }
- <link rel="stylesheet" type="text/css" href="@Url.Content("~/Content/css/uploadify.css")">
- <link rel="stylesheet" type="text/css" href="@Url.Content("~/Content/css/imgareaselect-animated.css")">
- <link rel="stylesheet" type="text/css" href="@Url.Content("~/Content/css/imgareaselect-default.css")">
- <link rel="stylesheet" type="text/css" href="@Url.Content("~/Content/css/imgareaselect-deprecated.css")">
- <script src="@Url.Content("~/Scripts/jquery-1.5.1.js ")" type="text/javascript"></script>
- <script src="@Url.Content("~/Scripts/js/ImgUpload.js")" type="text/javascript"></script>
- <script src="@Url.Content("~/Scripts/js/jquery.uploadify.min.js")" type="text/javascript"></script>
- <script src="@Url.Content("~/Scripts/js/jquery.imgareaselect.min.js")" type="text/javascript"></script>
- <style type="text/css">
- body
- {
- background:#fff;
- }
- </style>
- <div class="container-box">
- <p style="font-size: 110%; font-weight: bold; padding-left: 0.1em;">
- 1、择一张图片
- </p>
- <div >
- <div style=" float:left; height:50px">
- <input type="file" id="fileToUpload" name="fileToUpload" />
- </div>
- <div id="some_file_queue" style=" float:left;height:50px; width:300px; margin-left:30px; "></div>
- </div>
- <div style="float: left; clear:both;">
- <p style="font-size: 110%; font-weight: bold; padding-left: 0.1em;">
- 2、点击鼠标拖动相框截取图像
- </p>
- <div class="frame" style="margin: 0 0.3em; width: 300px; height: 300px;">
- <img id="PreviewImg" src="/Content/defaut.png" style="width: 300px; height: 300px;">
- </div>
- </div>
- <div style="float: left;">
- <p style="font-size: 110%; font-weight: bold; padding-left: 0.1em;">
- 3、预览截取的图像,点击保存。
- </p>
- <div style="text-align:center">
- <div class="frame" style="margin: 0 auto; width: 100px; height: 100px;">
- <img id="preview_img" src="/Content/defaut.png" style="width: 100px; height: 100px;">
- </div>
- </div>
- <div id="savebtn_swap" style="text-align:center; display:none">
- <div style="margin: 20 auto 0 auto; width:70px;">
- <input type="submit" id="savebtn" class="setting-submit-btn setting-submit-ml100" value="保存">
- </div>
- </div>
- <div class="save-ok" style="font-size: 110%;text-align:center; font-weight: bold; padding-left: 0.1em;display: none;" id="tiebaSaveOkMsg" >
- <div style="margin: 20 auto 0 auto; width:90px;">
- <p>保存成功</p>
- </div>
- </div>
- </div>
- </div>
5、在Home控制器中添加UploadImg,CutoutImg,SaveHeaderImg方法,添加后代码如下:
- using System;
- using System.Collections.Generic;
- using System.Linq;
- using System.Web;
- using System.Web.Mvc;
- using System.IO;
- using System.Drawing;
- namespace ImgUpload.Controllers
- {
- public class HomeController : Controller
- {
- //
- // GET: /Home/
- public ActionResult Index()
- {
- return View();
- }
- public ActionResult ImgUpload()
- {
- return View();
- }
- /// <summary>
- /// 上传图片接口 上传头像使用
- /// </summary>
- /// <returns></returns>
- [HttpPost]
- public String UploadImg()
- {
- HttpPostedFileBase postedFile_pic = Request.Files["Filedata"];//获取上传信息对象
- if (postedFile_pic != null && postedFile_pic.ContentLength != 0)
- {
- String PicFilePath = postedFile_pic.FileName;//获取上传的文件路径
- String PicName = Path.GetFileNameWithoutExtension(postedFile_pic.FileName);//获取文件名
- String SavePath = Server.MapPath("/Content/TempImg/");
- String PicExtension = PicFilePath.Substring(PicFilePath.LastIndexOf('.'));//获取拓展名
- //构造随机名称
- String Photo = PicName + "_" + DateTime.Now.Ticks + PicExtension;
- postedFile_pic.SaveAs(SavePath + Photo);
- //规格化
- System.Drawing.Image image = System.Drawing.Image.FromFile(SavePath + Photo);
- //接着创建一个System.Drawing.Bitmap对象,并设置你希望的缩略图的宽度和高度。
- int srcWidth = image.Width;
- int srcHeight = image.Height;
- Bitmap bmp = new Bitmap(300, 300);
- //从Bitmap创建一个System.Drawing.Graphics对象,用来绘制高质量的缩小图。
- System.Drawing.Graphics gr = System.Drawing.Graphics.FromImage(bmp);
- //设置 System.Drawing.Graphics对象的SmoothingMode属性为HighQuality
- gr.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
- //下面这个也设成高质量
- gr.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
- //下面这个设成High
- gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
- //把原始图像绘制成上面所设置宽高的缩小图
- System.Drawing.Rectangle rectDestination = new System.Drawing.Rectangle(0, 0, 300, 300);
- gr.DrawImage(image, rectDestination, 0, 0, srcWidth, srcHeight, GraphicsUnit.Pixel);
- String NewPhoto = "__" + PicName + "_" + DateTime.Now.Ticks + PicExtension;
- bmp.Save(SavePath + NewPhoto);
- bmp.Dispose();
- image.Dispose();
- FileInfo fi = new FileInfo(SavePath + Photo);
- fi.Delete();
- return NewPhoto;
- }
- return "Invalid file type";
- }
- /// <summary>
- /// 裁剪图片
- /// </summary>
- /// <param name="fileName"></param>
- /// <param name="top"></param>
- /// <param name="left"></param>
- /// <param name="width"></param>
- /// <param name="height"></param>
- /// <returns></returns>
- public String CutoutImg(String fileName, int top, int left, int width, int height)
- {
- String PicExtension = fileName.Substring(fileName.LastIndexOf('.'));//获取拓展名
- String Photo = "__" + DateTime.Now.Ticks + PicExtension;
- String RootPath = Server.MapPath("/");
- String HeaderImgPath = Server.MapPath("/Content/TempImg/");
- Bitmap bmp = new Bitmap(RootPath + fileName);
- Rectangle rect = new Rectangle(left, top, width, height);
- Bitmap tempBitmap = bmp.Clone(rect, bmp.PixelFormat);
- tempBitmap.Save(HeaderImgPath + Photo);
- bmp.Dispose();
- tempBitmap.Dispose();
- return Photo;
- }
- public String SaveHeaderImg(String fileName)
- {
- String RootPath = Server.MapPath("/");
- String PicExtension = fileName.Substring(fileName.LastIndexOf('.'));
- String NewName = "__" + DateTime.Now.Ticks + PicExtension;
- String HeaderImgPath = Server.MapPath("/Content/Header/");
- FileInfo fi = new FileInfo(RootPath + fileName);
- fi.MoveTo(HeaderImgPath + NewName);
- return "";
- }
- }
- }
6、运行,在浏览器中输入http://localhost:6133/Home/ImgUpload即可。
保存后的截图保存在Content/Header文件夹下面。
7、完整源码下载
http://www.youarebug.com/forum.php?mod=viewthread&tid=56&extra=page%3D1