本篇通过在配置文件中设置，对上传图片修剪后保存到指定文件夹。
相关兄弟篇：
MVC文件上传01-使用jquery异步上传并客户端验证类型和大小
MVC文件上传02-使用HttpPostedFileBase上传多个文件
MVC文件上传03-使用Request.Files上传多个文件
MVC文件上传04-使用客户端jQuery-File-Upload插件和服务端Backload组件实现多文件异步上传
MVC文件上传05-使用客户端jQuery-File-Upload插件和服务端Backload组件自定义上传文件夹
MVC文件上传06-使用客户端jQuery-File-Upload插件和服务端Backload组件自定义控制器上传多个文件
□ 思路
1、自定义控制器继承Backload的默认控制器BackloadController
2、自定义一个jQuery File Upload初始化js文件，使用自定义控制器的方法
3、在视图页面调用自定义jQuery File Upload初始化js文件
□ 安装Backload组件和jQuery File Upload插件
→在"程序包管理器控制台"输入：Install-Package Backload
→在"程序包管理器控制台"输入： Install-Package JQuery_File_Upload_Plugin
□ 自定义BaseController继承BackloadController
1: using System.Web.Mvc;
2:
3: namespace MvcApplication7.Controllers
4: {
5:public class BaseController : BackloadController
6:{
7://public ActionResult Index()
8://{
9:// return View();
10://}
11:
12:public async Task<ActionResult> FileHandler()
13:{
14: ActionResult result = await base.HandleRequestAsync();
15: return result;
16:}
17:}
18: }
□ 自定义HomeController继承BaseController
1: using System.Web.Mvc;
2: namespace MvcApplication7.Controllers
3: {
4:public class HomeController : BaseController
5:{
6:public ActionResult Index()
7:{
8: return View();
9:}
10:}
11: }
□ 自定义用于初始化jQuery File Upload的js文件main.js
其中，还限制了上传文件的格式。
1: $(function () {
2:'use strict';
3:
4:var url = '/Base/FileHandler';
5:// Initialize the jQuery File Upload widget:
6:$('#fileupload').fileupload({
7:// Uncomment the following to send cross-domain cookies:
8://xhrFields: {withCredentials: true},
9:url: url,
10:acceptFileTypes: /(jpg)|(jpeg)|(png)|(gif)$/i // Allowed file types
11:});
12:
13:// Enable iframe cross-domain access via redirect option:
14:$('#fileupload').fileupload(
15:'option',
16:'redirect',
17:window.location.href.replace(
18: /\/[^\/]*$/,
19: '/cors/result.html?%s'
20:)
21:);
22:
23:// Load existing files by an initial ajax request to the server after page loads up
24:// This is done by a simple jQuery ajax call, not by the FIle Upload plugin.,
25:// but the results are passed to the plugin with the help of the context parameter:
26:// context: $('#fileupload')[0] and the $(this)... call in the done handler.
27:// With ajax.context you can pass a JQuery object to the event handler and use "this".
28:$('#fileupload').addClass('fileupload-processing');
29:$.ajax({
30:// Uncomment the following to send cross-domain cookies:
31://xhrFields: {withCredentials: true},
32:url: url,
33:dataType: 'json',
34:context: $('#fileupload')[0]
35:}).always(function () {
36:$(this).removeClass('fileupload-processing');
37:}).done(function (result) {
38:$(this).fileupload('option', 'done')
39: .call(this, null, { result: result });
40:});
41: });
42:
43: $("document").ready(function () {
44:$('#fileupload')
45:.bind('fileuploaddestroy', function (e, data) {
46: // Event handler example. Do something if you need after file has been deleted on the server.
47: // (Refer to the client side documentatio).
48:});
49:
50: });
51:
□ _Layout.cshtml布局视图
1: <!DOCTYPE html>
2: <html>
3: <head>
4:<meta charset="utf-8" />
5:<meta name="viewport" content="width=device-width" />
6:<title>@ViewBag.Title</title>
7:@Styles.Render("~/Content/css")
8:@Styles.Render("~/Content/themes/base/css")
9:@Styles.Render("~/bundles/fileupload/bootstrap/BasicPlusUI/css")
10:@Scripts.Render("~/bundles/modernizr")
11: </head>
12: <body>
13:@RenderBody()
14:
15:@Scripts.Render("~/bundles/jquery")
16:@Scripts.Render("~/bundles/jqueryui")
17:@Scripts.Render("~/bundles/fileupload/bootstrap/BasicPlusUI/js")
18:@RenderSection("scripts", required: false)
19: </body>
20: </html>
21:
□ Home/Index.cshtml视图
展开@{ViewBag.Title = "Index";Layout = "~/Views/Shared/_Layout.cshtml";}<style type="text/css">.table-striped {width: 65%;}</style><div><!-- The file upload form used as target for the file upload widget --><form id="fileupload" action="/Backload/UploadHandler" method="POST" enctype="multipart/form-data"><!-- Redirect browsers with JavaScript disabled to the origin page --><noscript><input type="hidden" name="redirect" value="/"></noscript><!-- The fileupload-buttonbar contains buttons to add/delete files and start/cancel the upload --><div class="row fileupload-buttonbar"><div class="span7"><!-- The fileinput-button span is used to style the file input field as button --><span class="btn btn-success fileinput-button"><i class="icon-plus icon-white"></i><span>添加文件...</span><input type="file" name="files[]" multiple></span><button type="submit" class="btn btn-primary start"><i class="icon-upload icon-white"></i><span>开始上传</span></button><button type="reset" class="btn btn-warning cancel"><i class="icon-ban-circle icon-white"></i><span>取消上传</span></button><button type="button" class="btn btn-danger delete"><i class="icon-trash icon-white"></i><span>删除</span></button><input type="checkbox" class="toggle"><!-- The loading indicator is shown during file processing --><span class="fileupload-loading"></span></div><!-- The global progress information --><div class="span5 fileupload-progress fade"><!-- The global progress bar --><div class="progress progress-success progress-striped active" role="progressbar" aria-valuemin="0" aria-valuemax="100"><div class="bar" style="width:0%;"></div></div><!-- The extended global progress information --><div class="progress-extended"> </div></div></div><!-- The table listing the files available for upload/download --><table role="presentation" class="table table-striped"><tbody class="files" data-toggle="modal-gallery" data-target="#modal-gallery"></tbody></table></form> <!-- The template to display files available for upload --><script id="template-upload" type="text/x-tmpl">{% for (var i=0, file; file=o.files[i]; i++) { %}<tr class="template-upload fade"><td><span class="preview"></span></td><td><p class="name">{%=file.name%}</p>{% if (file.error) { %}<div><span class="label label-important">Error</span> {%=file.error%}</div>{% } %}</td><td><p class="size">{%=o.formatFileSize(file.size)%}</p>{% if (!o.files.error) { %}<div class="progress progress-success progress-striped active" role="progressbar" aria-valuemin="0" aria-valuemax="100" aria-valuenow="0"><div class="bar" style="width:0%;"></div></div>{% } %}</td><td>{% if (!o.files.error && !i && !o.options.autoUpload) { %}<button class="btn btn-primary start"><i class="icon-upload icon-white"></i><span>Start</span></button>{% } %}{% if (!i) { %}<button class="btn btn-warning cancel"><i class="icon-ban-circle icon-white"></i><span>Cancel</span></button>{% } %}</td></tr>{% } %}</script><!-- The template to display files available for download --><script id="template-download" type="text/x-tmpl">{% for (var i=0, file; file=o.files[i]; i++) { %}<tr class="template-download fade"><td><span class="preview">{% if (file.thumbnail_url) { %}<a href="{%=file.url%}" title="{%=file.name%}" data-gallery="gallery" download="{%=file.name%}"><img src="{%=file.thumbnail_url%}"></a>{% } %}</span></td><td><p class="name"><a href="{%=file.url%}" title="{%=file.name%}" data-gallery="{%=file.thumbnail_url&&'gallery'%}" download="{%=file.name%}">{%=file.name%}</a></p>{% if (file.error) { %}<div><span class="label label-important">Error</span> {%=file.error%}</div>{% } %}</td><td><span class="size">{%=o.formatFileSize(file.size)%}</span></td><td><button class="btn btn-danger delete" data-type="{%=file.delete_type%}" data-url="{%=file.delete_url%}"{% if (file.delete_with_credentials) { %} data-xhr-fields='{"withCredentials":true}'{% } %}><i class="icon-trash icon-white"></i><span>Delete</span></button><input type="checkbox" name="delete" value="1" class="toggle"></td></tr>{% } %}</script></div>@section scripts{@* <script src="~/Scripts/FileUpload/backload.demo.js"></script>*@<script src="~/Scripts/main.js"></script>}
□ web.config
1: <configuration>
2: <configSections>
3: ...
4: <section name="backload" type="Backload.Configuration.BackloadSection, Backload, Version=1.9.3.1, Culture=neutral, PublicKeyToken=02eaf42ab375d363" requirePermission="false" /></configSections>
5: <configSections>
6: <backload configSource="Web.backload.config" />
7: </configuration>
□ 所有Backload的配置放在Web.backload.config中
1: <?xml version="1.0"?>
2:
3: <backload xsi:noNamespaceSchemaLocation="Web.Backload.xsd" xmlns:xsi="/2001/XMLSchema-instance" xmlns:name="urn:backload-schema" thumbsUrlPattern="{Backload}">
4:
5: <images width="200" height="200" dpi="96" resizeMode="ratio" />
6: <thumbnails path="" width="60" height="60" canvasColor="#00000000" resizeMode="place" imageType="image/png" />
7: <fileSystem filesRoot="~/Upload" />
8: <cacheManager lastModified="true" etag="true"/>
9: </backload>
● width和height实际上设置的是画布Canvas的大小。
● 没有resizeMode属性：保持上传图片的大小不变
● resizeMode="ration": 当图片的宽度大于画布的宽度，图片的宽度修剪为画布的宽度，图片的高度等比例缩放，画布背景不显示
● resizeMode="fit": 当图片的宽度大于画布的宽度，图片的宽度修剪为画布的宽度，图片的高度等比例缩放，画布背景显示
● resizeMode="place": 当图片的宽度小于画布的宽度，图片的宽度修剪为画布的宽度，图片的高度等比例缩放，画布背景显示
● resizeMode="crop": 图片的宽度或高度充满画布的宽度或高度，空白的画布区域裁剪掉。
□ 结果
上传界面：
由于设置了path=""，所以没有了缩略图：
由于设置了resizeMode="ratio"，上传图片宽度不变，高度按比例缩小：
□ 设置文件夹带缩略图文件夹path="_thumb"
1: <backload xsi:noNamespaceSchemaLocation="Web.Backload.xsd" xmlns:xsi="/2001/XMLSchema-instance" xmlns:name="urn:backload-schema" thumbsUrlPattern="{Backload}">
2:
3: <images width="200" height="200" dpi="96" resizeMode="ratio" />
4: <thumbnails path="_thumb" width="60" height="60" canvasColor="#00000000" resizeMode="place" imageType="image/png" />
5: <fileSystem filesRoot="~/Upload" />
6: <cacheManager lastModified="true" etag="true"/>
7: </backload>
增加一个图片：
由于设置了path="_thumb"，所以有了缩略图文件夹：
由于缩略图设置了resizeMode="place"，图片宽度等于画布宽度，高度等比例缩放，显示背景：
由于在main.js中设置了acceptFileTypes: /(jpg)|(jpeg)|(png)|(gif)$/i，pdf格式不允许：
参考资料：
※ / Backload官网
※ /blackcity/Backload#examples Backload例子
※ /packages/Backload/ nuget上的Backload
※ http://blueimp.github.io/jQuery-File-Upload/ jQuery File Upload官网
※ /blueimp/jQuery-File-Upload/wiki github上的jQuery File Upload介绍
※ /blueimp/jQuery-File-Upload github上的jQuery File Upload源码
※ /packages/JQueryFileUpload_Demo_with_Backload/ 下载jQuery File Upload结合Backload的MVC案例
