移动端图片上传方法

function UploadBase64() {
    this.sw = 0;
    this.sh = 0;
    this.tw = 0;
    this.th = 0;
    this.scale = 0;
    this.maxWidth = 0;
    this.maxHeight = 0;
    this.maxSize = 0;
    this.fileSize = 0;
    this.fileDate = null;
    this.fileType = ‘‘;
    this.fileName = ‘‘;
    this.input = null;
    this.canvas = null;
    this.mime = {};
    this.type = ‘‘;
    this.callback = function () { };
    this.loading = function () { };
}

UploadBase64.prototype.init = function (options) {
    this.maxWidth = options.maxWidth || 800;
    this.maxHeight = options.maxHeight || 600;
    this.maxSize = options.maxSize || 3 * 1024 * 1024;
    this.input = options.input;
    this.mime = { ‘png‘: ‘image/png‘, ‘jpg‘: ‘image/jpeg‘, ‘jpeg‘: ‘image/jpeg‘, ‘bmp‘: ‘image/bmp‘ };
    this.callback = options.callback || function () { };
    this.loading = options.loading || function () { };

    this._addEvent();
};

/** 
* @description 绑定事件 
* @param {Object} elm 元素 
* @param {Function} fn 绑定函数 
*/
UploadBase64.prototype._addEvent = function () {
    var _this = this;

    function tmpSelectFile(ev) {
        _this._handelSelectFile(ev);
    }

    this.input.addEventListener(‘change‘, tmpSelectFile, false);
};

/** 
* @description 绑定事件 
* @param {Object} elm 元素 
* @param {Function} fn 绑定函数 
*/
UploadBase64.prototype._handelSelectFile = function (ev) {
    var file = ev.target.files[0];

    this.type = file.type

    // 如果没有文件类型，则通过后缀名判断（解决微信及360浏览器无法获取图片类型问题） 
    if (!this.type) {
        this.type = this.mime[file.name.match(/\.([^\.]+)$/i)[1]];
    }

    if (!/image.(png|jpg|jpeg|bmp)/.test(this.type)) {
        alert(‘选择的文件类型不是图片‘);
        return;
    }

    if (file.size > this.maxSize) {
        alert(‘选择文件大于‘ + this.maxSize / 1024 / 1024 + ‘M，请重新选择‘);
        return;
    }

    this.fileName = file.name;
    this.fileSize = file.size;
    this.fileType = this.type;
    this.fileDate = file.lastModifiedDate;

    this._readImage(file);
};

/** 
* @description 读取图片文件 
* @param {Object} image 图片文件 
*/
UploadBase64.prototype._readImage = function (file) {
    var _this = this;

    function tmpCreateImage(uri) {
        _this._createImage(uri);
    }

    this.loading();

    this._getURI(file, tmpCreateImage);
};

/** 
* @description 通过文件获得URI 
* @param {Object} file 文件 
* @param {Function} callback 回调函数，返回文件对应URI 
* return {Bool} 返回false 
*/
UploadBase64.prototype._getURI = function (file, callback) {
    var reader = new FileReader();
    var _this = this;

    function tmpLoad() {
        // 头不带图片格式，需填写格式 
        var re = /^data:base64,/;
        var ret = this.result + ‘‘;

        if (re.test(ret)) ret = ret.replace(re, ‘data:‘ + _this.mime[_this.fileType] + ‘;base64,‘);

        callback && callback(ret);
    }

    reader.onload = tmpLoad;

    reader.readAsDataURL(file);

    return false;
};

/** 
* @description 创建图片 
* @param {Object} image 图片文件 
*/
UploadBase64.prototype._createImage = function (uri) {
    var img = new Image();
    var _this = this;

    function tmpLoad() {
        _this._drawImage(this);
    }

    img.onload = tmpLoad;

    img.src = uri;
};

/** 
* @description 创建Canvas将图片画至其中，并获得压缩后的文件 
* @param {Object} img 图片文件 
* @param {Number} width 图片最大宽度 
* @param {Number} height 图片最大高度 
* @param {Function} callback 回调函数，参数为图片base64编码 
* return {Object} 返回压缩后的图片 
*/
UploadBase64.prototype._drawImage = function (img, callback) {
    this.sw = img.width;
    this.sh = img.height;
    this.tw = img.width;
    this.th = img.height;

    this.scale = (this.tw / this.th).toFixed(2);

    if (this.sw > this.maxWidth) {
        this.sw = this.maxWidth;
        this.sh = Math.round(this.sw / this.scale);
    }

    if (this.sh > this.maxHeight) {
        this.sh = this.maxHeight;
        this.sw = Math.round(this.sh * this.scale);
    }

    this.canvas = document.createElement(‘canvas‘);
    var ctx = this.canvas.getContext(‘2d‘);

    this.canvas.width = this.sw;
    this.canvas.height = this.sh;

    ctx.drawImage(img, 0, 0, img.width, img.height, 0, 0, this.sw, this.sh);

    this.callback(this.canvas.toDataURL(this.type));

    ctx.clearRect(0, 0, this.tw, this.th);
    this.canvas.width = 0;
    this.canvas.height = 0;
    this.canvas = null;
}; 

    <!doctype html> 
    <html> 
    <head> 
    <meta charset="utf-8"> 
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"> 
    <title>手机端图片上传</title>     
    </head> 
     
    <body> 
    <script type="text/javascript" charset="utf-8" src="/scripts/jquery/jquery-1.11.2.min.js"></script>
    <script src="scripts/jquery/jquery.uploadBase64.js" type="text/javascript"></script>
    <input type="file" accept="image/*" id="file" style="display:none"> 
    <div id="upload-box" style="width:200px;height:45px;line-height:45px;text-align:center;color:#fff; background:#02598e; cursor:pointer;">移动端图片上传</div> 
    <script>
        document.addEventListener(‘DOMContentLoaded‘, init, false);
        function init() {
            var u = new UploadBase64();
            u.init({
                input: document.querySelector(‘#file‘),
                callback: function (base64) {
                    $.ajax({
                        url: "/upload_ajax.ashx?action=UploadBase64",
                        data: { base64: base64, type: this.fileType },
                        type: ‘post‘,
                        dataType: ‘json‘,
                        success: function (i) {
                            alert(i.info);
                        }
                    })
                },
                loading: function () {

                }
            });
        }
        $(function () {
            $("#upload-box").click(function () {
                $("#file").trigger("click");
            })
        })
    </script> 
    </body> 
    </html>

using System;
using System.Collections;
using System.IO;
using System.Collections.Generic;
using System.Web.SessionState;
using System.Web;
using System.Drawing;

namespace DianShang.Web.tools
{
    /// <summary>
    /// 文件上传处理页
    /// </summary>
    public class upload_ajaxs : IHttpHandler, IRequiresSessionState
    {
        public void ProcessRequest(HttpContext context)
        {
            //取得处事类型
            string action = context.Request.QueryString["action"];

            switch (action)
            {
                case "UpLoadBase64": //Base64编码上传
                    UpLoadBase64(context);
                    break;
                default: //普通上传
                    UpLoadFile(context);
                    break;
            }

        }
        #region Base64编码上传===================================
        private void UpLoadBase64(HttpContext context)
        {
            Model.siteconfig siteConfig = new BLL.siteconfig().loadConfig();
            string _delpath = context.Request.Form["delpath"];
            string _upfile = context.Request.Form["base64"];            
            string[] tmpArr = _upfile.Split(‘,‘);
            byte[] base64 = Convert.FromBase64String(tmpArr[1]);
            MemoryStream ms = new MemoryStream(base64);
            System.Drawing.Image postedFile = System.Drawing.Image.FromStream(ms);

            string path = String.Format("/upload/{0}/{0}.jpg", DateTime.Now.ToString("yyyyMMddHHss"));

            //保存文件
            postedFile.Save(context.Server.MapPath(path));
            //处理完毕，返回JOSN格式的文件信息
            context.Response.Write("{\"status\": 1, \"msg\": \"上传文件成功！\", \"path\": \"" + path + "\"}");
            context.Response.End();
            
        }
        #endregion

        #region 普通上传===================================
        private void UpLoadFile(HttpContext context)
        {
            
        }
        #endregion
        
        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}