基于asp.net实现图片在线上传并在线裁剪功能

1、说明

　　接上一篇文章asp.net uploadify实现多附件上传功能完成后，又突然用到头像上传并在线裁剪。在网上找个众多例子都没有符合要求的，有一篇文章写的不错,Asp.Net平台下的图片在线裁剪功能的实现代码(源码打包),大家可以看下

2、组成

　　首先说明一下代码实现所用到的技术，仅供参考：

　　　　开发工具：vs2010

　　　　目标框架：.NET Framework3.5

　　　　jcrop：Jcrop.js v0.9.12

　　　　Uploadify：uploadify-v3.1

　　　　Jquery：jquery-1.9.0.js

　　最后我会将整个Demo上传，如果同学们的电脑上有开发环境可直接打开项目解决方案运行。

3、代码

Default.aspx（测试页面）

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="ImgJcrop._Default" %>
<!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 runat="server">
  <title>在线裁剪</title>
  <link href="Scripts/jcrop/jquery.Jcrop.css" rel="stylesheet" type="text/css" />
  <link href="Scripts/uploadify-v3.1/uploadify.css" rel="stylesheet" type="text/css" />
  <script src="Scripts/jquery.1.9.0.min.js" type="text/javascript"></script>
  <script src="Scripts/jcrop/jquery.Jcrop.js" type="text/javascript"></script>
  <script src="Scripts/uploadify-v3.1/jquery.uploadify-3.1.js" type="text/javascript"></script>
  <script type="text/javascript">
    $(function () {
      var jcrop_api, boundx, boundy;
      $("#file_upload").uploadify({
        "auto": true,
        "buttonText": "选择图片",
        "swf": "Scripts/uploadify-v3.1/uploadify.swf",
        "uploader": "App_Handler/Uploadify.ashx?action=upload",
        "fileTypeExts": "*.jpg; *.jpeg; *.gif; *.png; *.bmp",
        "fileTypeDesc": "支持的格式：",
        "multi": false,
        "removeCompleted": false,
        "onUploadStart": function (file) {
          $("#file_upload-queue").hide();
        },
        "onUploadSuccess": function (file, data, response) {
          var row = eval("[" + data + "]");
          if (row[0]["status"] == 0) {
            $("#cutimg").html("<img id=\"imgOriginal\" name=\"imgOriginal\" /><div style=\"overflow: hidden; margin-top: 20px;\"><div style=\"width: 120px; height: 120px; overflow: hidden;\"><img id=\"imgPreview\" /></div><br /><input type=\"button\" id=\"btnImgCut\" onclick=\"cutSaveImg()\" value=\"裁剪并保存图片\" /></div>");
            $("#cutimg img").each(function () { $(this).attr("src", row[0]["message"]); });
            $("#hidImgUrl").val(row[0]["message"]);
            $('#imgOriginal').Jcrop({
              onChange: updatePreview,
              onSelect: updatePreview,
              aspectRatio: 1,
              //maxSize: [120, 120],
              setSelect: [0, 0, 120, 120]
            }, function () {
              var bounds = this.getBounds();
              boundx = bounds[0];
              boundy = bounds[1];
              jcrop_api = this;
            });
          } else {
            alert(row[0]["message"]);
          }
        }
      });

      function updatePreview(c) {

        if (parseInt(c.w) > 0) {
          var rx = 120 / c.w;
          var ry = 120 / c.h;

          $("#imgPreview").css({
            width: Math.round(rx * boundx) + "px",
            height: Math.round(ry * boundy) + "px",
            marginLeft: "-" + Math.round(rx * c.x) + "px",
            marginTop: "-" + Math.round(ry * c.y) + "px"
          });
        }
        $("#hidXone").val(c.x);
        $("#hidYone").val(c.y);
        $("#hidXtwo").val(c.hidXtwo);
        $("#hidYtwo").val(c.hidYtwo);
        $("#hidImgWidth").val(c.w);
        $("#hidImgHeight").val(c.h);
      };
    });

    function cutSaveImg() {
      $.ajax({
        type: "post",
        url: "App_Handler/Uploadify.ashx?action=cutsaveimg",
        data: { strImgUrl: $("#imgOriginal")[0].src, hidXone: $("#hidXone").val(), hidYone: $("#hidYone").val(), hidImgWidth: $("#hidImgWidth").val(), hidImgHeight: $("#hidImgHeight").val() },
        dataType: "html",
        success: function (data) {
          var row = eval("[" + data + "]");
          if (row[0]["status"] == 0) { }
          alert(row[0]["message"]);
        }
      });
    }
  </script>
</head>
<body>
  <form id="form1" runat="server">
  <div>
    <input type="file" id="file_upload" name="file_upload" />
  </div>
  <div id="cutimg">
  </div>
  <asp:HiddenField ID="hidXone" runat="server" />
  <asp:HiddenField ID="hidYone" runat="server" />
  <asp:HiddenField ID="hidXtwo" runat="server" />
  <asp:HiddenField ID="hidYtwo" runat="server" />
  <asp:HiddenField ID="hidImgWidth" runat="server" />
  <asp:HiddenField ID="hidImgHeight" runat="server" />
  <asp:HiddenField ID="hidImgUrl" runat="server" />
  </form>
</body>
</html>

Uploadify.ashx（一般处理程序）

<%@ WebHandler Language="C#" Class="UploadifyUpload" %>
using System;
using System.Collections;
using System.Data;
using System.Web;
using System.Linq;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.SessionState;
using System.IO;
using System.Collections.Generic;
using System.Web.UI.WebControls;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
public class UploadifyUpload : IHttpHandler, IRequiresSessionState
{
  public void ProcessRequest(HttpContext context)
  {
    context.Response.ContentType = "text/plain";
    context.Response.Charset = "utf-8";

    string action = context.Request["action"];
    switch (action)
    {
      case "upload":
        //上传图片
        upload(context);
        break;
      case "cutsaveimg":
        //裁剪并保存
        cutsaveimg(context);
        break;
    }
    context.Response.End();
  }
  /// <summary>
  /// 上传图片
  /// </summary>
  /// <param name="context"></param>
  private void upload(HttpContext context)
  {
    HttpPostedFile postedFile = context.Request.Files["Filedata"];
    if (postedFile != null)
    {
      string fileName, fileExtension;
      int fileSize;
      fileName = postedFile.FileName;
      fileSize = postedFile.ContentLength;
      if (fileName != "")
      {
        fileExtension = postedFile.FileName.Substring(postedFile.FileName.LastIndexOf('.'));
        string strPath = context.Server.MapPath("/") + "\\App_File\\Upload\\";//设置文件的路径
        string strFileName = "upload" + DateTime.Now.ToString("yyyyMMddHHmmss") + fileExtension;
        string strFileUrl = strPath + strFileName;//保存文件路径
        if (!Directory.Exists(strPath))
        {
          Directory.CreateDirectory(strPath);
        }
        postedFile.SaveAs(strFileUrl);//先保存源文件
        context.Response.Write("{\"status\":0,\"message\":\"/App_File/Upload/" + strFileName + "\"}");
      }
      else
      {
        context.Response.Write("{\"status\":1,\"message\":\"上传失败！\"}");
      }
    }
    else
    {
      context.Response.Write("{\"status\":1,\"message\":\"上传失败！\"}");
    }
  }
  /// <summary>
  /// 裁剪并保存图片
  /// </summary>
  /// <param name="context"></param>
  private void cutsaveimg(HttpContext context)
  {
    string strImgUrl = context.Request["strImgUrl"];
    string strXone = context.Request["hidXone"];
    string strYone = context.Request["hidYone"];
    string strImgWidth = context.Request["hidImgWidth"];
    string strImgHeight = context.Request["hidImgHeight"];
    string[] urls = strImgUrl.Split('/');
    string str_url = urls.Last();
    try
    {
      string strOldFiel = context.Server.MapPath("~/App_File/Upload/");
      string strNewFiel = context.Server.MapPath("~/App_File/Cut/");
      string strOldUrl = Path.Combine(strOldFiel, str_url);
      string strNewUrl = Path.Combine(strNewFiel, "cut" + DateTime.Now.ToString("yyyyMMddHHmmss") + "." + str_url.Split('.')[1]);
      if (!Directory.Exists(strNewFiel))
      {
        Directory.CreateDirectory(strNewFiel);
      }
      int intStartX = int.Parse(strXone);
      int intStartY = int.Parse(strYone);
      int intWidth = int.Parse(strImgWidth);
      int intHeight = int.Parse(strImgHeight);
      CutGeneratedImage(intStartX, intStartY, intWidth, intHeight, strOldUrl, strNewUrl);
      context.Response.Write("{\"status\":0,\"message\":\"裁剪成功并保存！\"}");
    }
    catch
    {
      context.Response.Write("{\"status\":1,\"message\":\"裁剪失败！\"}");
    }
  }
  /// <summary>
  /// 裁剪图片
  /// </summary>
  /// <param name="intWidth">要缩小裁剪图片宽度</param>
  /// <param name="intHeight">要缩小裁剪图片长度</param>
  /// <param name="strOldImgUrl">要处理图片路径</param>
  /// <param name="strNewImgUrl">处理完毕图片路径</param>
  public void CutGeneratedImage(int intStartX, int intStartY, int intWidth, int intHeight, string strOldImgUrl, string strNewImgUrl)
  {
    //上传标准图大小
    int intStandardWidth = 120;
    int intStandardHeight = 120;

    int intReduceWidth = 0; // 缩小的宽度
    int intReduceHeight = 0; // 缩小的高度
    int intCutOutWidth = 0; // 裁剪的宽度
    int intCutOutHeight = 0; // 裁剪的高度
    int level = 100; //缩略图的质量 1-100的范围
    //获得缩小，裁剪大小
    if (intStandardHeight * intWidth / intStandardWidth > intHeight)
    {
      intReduceWidth = intWidth;
      intReduceHeight = intStandardHeight * intWidth / intStandardWidth;
      intCutOutWidth = intWidth;
      intCutOutHeight = intHeight;
    }
    else if (intStandardHeight * intWidth / intStandardWidth < intHeight)
    {
      intReduceWidth = intStandardWidth * intHeight / intStandardHeight;
      intReduceHeight = intHeight;
      intCutOutWidth = intWidth;
      intCutOutHeight = intHeight;
    }
    else
    {
      intReduceWidth = intWidth;
      intReduceHeight = intHeight;
      intCutOutWidth = intWidth;
      intCutOutHeight = intHeight;
    }
    //通过连接创建Image对象
    //System.Drawing.Image oldimage = System.Drawing.Image.FromFile(strOldImgUrl);
    //oldimage.Save(Server.MapPath("tepm.jpg"));
    //oldimage.Dispose();
    //缩小图片
    Bitmap bm = new Bitmap(strOldImgUrl);
    //处理JPG质量的函数
    ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
    ImageCodecInfo ici = null;
    foreach (ImageCodecInfo codec in codecs)
    {
      if (codec.MimeType == "image/jpeg")
      {
        ici = codec;
        break;
      }
    }
    EncoderParameters ep = new EncoderParameters();
    ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)level);
    //裁剪图片
    Rectangle cloneRect = new Rectangle(intStartX, intStartY, intCutOutWidth, intCutOutHeight);
    PixelFormat format = bm.PixelFormat;
    Bitmap cloneBitmap = bm.Clone(cloneRect, format);
    //保存图片
    cloneBitmap.Save(strNewImgUrl, ici, ep);
    bm.Dispose();
  }
  public bool IsReusable
  {
    get
    {
      return false;
    }
  }
}　　

4、最后奉上Demo

　　ImgJcrop

以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以留言交流，同时也希望多多支持我们！