移动端图片上传方法
实现步骤
一、隐藏<input type="file" id="file" name="Filedata" style="display:none;" accept="image/*" />
二、创建上传按钮<div id="upload-box"></div>
三、绑定事件
$("#upload-box").click(function () {
$("#file").trigger("click");
})
插件代码jquery.uploadBase64.js
function UploadBase64() {
this.sw = 0;
this.sh = 0;
this.tw = 0;
this.th = 0;
this.scale = 0;
this.maxWidth = 0;
this.maxHeight = 0;
this.maxSize = 0;
this.fileSize = 0;
this.fileDate = null;
this.fileType = '';
this.fileName = '';
this.input = null;
this.canvas = null;
this.mime = {};
this.type = '';
this.callback = function () { };
this.loading = function () { };
}
UploadBase64.prototype.init = function (options) {
this.maxWidth = options.maxWidth || 800;
this.maxHeight = options.maxHeight || 600;
this.maxSize = options.maxSize || 3 * 1024 * 1024;
this.input = options.input;
this.mime = { 'png': 'image/png', 'jpg': 'image/jpeg', 'jpeg': 'image/jpeg', 'bmp': 'image/bmp' };
this.callback = options.callback || function () { };
this.loading = options.loading || function () { };
this._addEvent();
};
/**
* @description 绑定事件
* @param {Object} elm 元素
* @param {Function} fn 绑定函数
*/
UploadBase64.prototype._addEvent = function () {
var _this = this;
function tmpSelectFile(ev) {
_this._handelSelectFile(ev);
}
this.input.addEventListener('change', tmpSelectFile, false);
};
/**
* @description 绑定事件
* @param {Object} elm 元素
* @param {Function} fn 绑定函数
*/
UploadBase64.prototype._handelSelectFile = function (ev) {
var file = ev.target.files[0];
this.type = file.type
// 如果没有文件类型，则通过后缀名判断（解决微信及360浏览器无法获取图片类型问题）
if (!this.type) {
this.type = this.mime[file.name.match(/.([^.]+)$/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;
};
HTML代码
<!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="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>
asp.net后台处理代码：upload_ajax.ashx
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;
}
}
}
}