MVC文件上传07-使用客户端jQuery-File-Upload插件和服务端Backload组件裁剪上传图片

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。

□ 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 {
         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="0%;"></div>
                    </div>
                    <!-- The extended global progress information -->
                    <div class="progress-extended">&nbsp;</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="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="http://www.w3.org/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="http://www.w3.org/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：
※ http://backload.org/ Backload官网
※ https://github.com/blackcity/Backload#examples Backload例子
※ http://nuget.org/packages/Backload/ nuget上的Backload

※ http://blueimp.github.io/jQuery-File-Upload/ jQuery File Upload官网
※ https://github.com/blueimp/jQuery-File-Upload/wiki github上的jQuery File Upload介绍
※ https://github.com/blueimp/jQuery-File-Upload github上的jQuery File Upload源码

※ https://www.nuget.org/packages/JQueryFileUpload_Demo_with_Backload/ 下载jQuery File Upload结合Backload的MVC案例

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原文地址：https://www.cnblogs.com/darrenji/p/3620618.html