学步园

SWFUpload可以说是目前最好的多文件上传工具之一，虽然它是基于flash插件开发的，但是相比目前很多js多文件上传还是具有很多优点：

可以同时选择多个文件上传（注意是以此选择文件）

无刷新上传

可以显示进度条

良好的浏览器兼容性

兼容其他js类库

SWFUpload另个优点就是它优秀的设计，它提供了一组简明的Javascript事件，借助它们开发者可以方便的在文件上传过程中更新页面的内容。

下面是SWFUpload在具体使用过程中js代码

MultiFileHandler.js

function fileQueueError(file, errorCode, message) {
	try {
		var imageName = "error.gif";
		var errorName = "";
		if (errorCode === SWFUpload.errorCode_QUEUE_LIMIT_EXCEEDED) {
			errorName = "文件超过最大上传个数！";
		}

		if (errorName !== "") {
			alert(errorName);
			return;
		}

		switch (errorCode) {
		case SWFUpload.QUEUE_ERROR.ZERO_BYTE_FILE:
			imageName = "zerobyte.gif";
			break;
		case SWFUpload.QUEUE_ERROR.FILE_EXCEEDS_SIZE_LIMIT:
			imageName = "toobig.gif";
			break;
		case SWFUpload.QUEUE_ERROR.ZERO_BYTE_FILE:
		case SWFUpload.QUEUE_ERROR.INVALID_FILETYPE:
		default:
			alert(message);
			break;
		}

		addImage("/modules/commons/view/multifileupload/images/" + imageName);

	} catch (ex) {
		this.debug(ex);
	}

}

function fileDialogComplete(numFilesSelected, numFilesQueued) {
	try {
		if (numFilesQueued > 0) {
			this.startUpload();
		}
	} catch (ex) {
		this.debug(ex);
	}
}

function uploadProgress(file, bytesLoaded) {

	try {
		var percent = Math.ceil((bytesLoaded / file.size) * 100);

		var progress = new FileProgress(file,  this.customSettings.upload_target);
		progress.setProgress(percent);
		if (percent == 100) {
		    if(showThumbnail){
			    progress.setStatus("正在创建缩略图...");
			}
			progress.toggleCancel(false, this);
			uploadNum++;
		    setUploadNumber(uploadNum);
		} else {
			progress.setStatus("正在上传中，已完成"+percent+"%");
			progress.toggleCancel(true, this);
		}
	} catch (ex) {
		this.debug(ex);
	}
}

//文件数据发送成功，不管是否成功保存;其serverData是否服务器端处理完以后的返回值
//这里规定返回值必须为success才代表成功
var serverErrorInfo="";
function uploadSuccess(file, serverData) {
	try {
	    var sd=serverData.replace(/ /gi,'').replace(/　/gi,'').replace(/\r/gi,'').replace(/\n/gi,'').replace(/\t/gi,'');
	    if(showThumbnail){
	        var filePath="..";
	        if(savePath!=''){
                filePath=filePath+"/"+savePath;
            }
	        filePath=filePath+'/'+file.name;
		    addImage(filePath);
        }
		var progress = new FileProgress(file,  this.customSettings.upload_target);
        if(showThumbnail){
		    progress.setStatus("缩略图创建完成！");
		}
		if(sd!=''){
		    if(sd!='success'){
		        if(serverErrorInfo!=''){
		            serverErrorInfo+='<br />';
		        }
		        serverErrorInfo+=sd;
		        document.getElementById('divError').innerHTML=serverErrorInfo;
		    }
		}
		progress.toggleCancel(false);


	} catch (ex) {
		this.debug(ex);
	}
}

//服务器端返回非空值才认为上传成功，触发下面事件
function uploadComplete(file) {
	try {
		/*  I want the next upload to continue automatically so I'll call startUpload here */
		if (this.getStats().files_queued > 0) {
			this.startUpload();
		} else {
			var progress = new FileProgress(file,  this.customSettings.upload_target);
			progress.setComplete();
			if(!isCancel){
			    progress.setStatus("文件上传成功！");
			}else{
			    progress.setStatus("上传已取消！");
			    isCancel=false;
			}
			progress.toggleCancel(false);
		}
	} catch (ex) {
		this.debug(ex);
	}
}

function uploadError(file, errorCode, message) {
	var imageName =  "error.gif";
	var progress;
	try {
		switch (errorCode) {
		case SWFUpload.UPLOAD_ERROR.FILE_CANCELLED:
			try {
				progress = new FileProgress(file,  this.customSettings.upload_target);
				progress.setCancelled();
				progress.setStatus("取消完成！");
				progress.toggleCancel(false);
			}
			catch (ex1) {
				this.debug(ex1);
			}
			break;
		case SWFUpload.UPLOAD_ERROR.UPLOAD_STOPPED:
			try {
				progress = new FileProgress(file,  this.customSettings.upload_target);
				progress.setCancelled();
				progress.setStatus("已停止！");
				progress.toggleCancel(true);
			}
			catch (ex2) {
				this.debug(ex2);
			}
		case SWFUpload.UPLOAD_ERROR.UPLOAD_LIMIT_EXCEEDED:
			imageName = "uploadlimit.gif";
			break;
		default:
			alert(message);
			break;
		}

		addImage("/modules/commons/view/multifileupload/images/" + imageName);

	} catch (ex3) {
		this.debug(ex3);
	}

}


function addImage(src) {
    var imageName=getFileName(src);
    var divImage=document.createElement("span");
    divImage.style.margin = "5px";
    divImage.style.padding = "1px";
    divImage.style.width = "59px";
    divImage.style.height = "85px";
    divImage.style.display="block";
    divImage.style.border="10px";
    divImage.style.float="left";
    divImage.attachEvent("onmouseover", setBackground(divImage,"#FFFACD")); 
    divImage.attachEvent("onmouseout", setBackground(divImage,"#FFFFFF")); 
    
	var newImg = document.createElement("img");
	//newImg.style.margin = "5px";
	newImg.style.width = "59px";
	newImg.style.height = "59px";
	newImg.alt=imageName;
	
	var divImageName=document.createElement("div");
	divImageName.style.marginTop="5px";
	divImageName.style.width="59px";
	divImageName.style.height="20px";
	divImageName.style.textAlign="center";
	divImageName.innerHTML=imageName;
    
    divImage.appendChild(newImg);
    divImage.appendChild(divImageName);
	document.getElementById("thumbnails").appendChild(divImage);
	if (newImg.filters) {
		try {
			newImg.filters.item("DXImageTransform.Microsoft.Alpha").opacity = 0;
		} catch (e) {
			// If it is not set initially, the browser will throw an error.  This will set it if it is not set yet.
			newImg.style.filter = 'progid:DXImageTransform.Microsoft.Alpha(opacity=' + 0 + ')';
		}
	} else {
		newImg.style.opacity = 0;
	}

	newImg.onload = function () {
		fadeIn(newImg, 0);
	};
	newImg.src = src;
}

function fadeIn(element, opacity) {
	var reduceOpacityBy = 5;
	var rate = 30;	// 15 fps


	if (opacity < 100) {
		opacity += reduceOpacityBy;
		if (opacity > 100) {
			opacity = 100;
		}

		if (element.filters) {
			try {
				element.filters.item("DXImageTransform.Microsoft.Alpha").opacity = opacity;
			} catch (e) {
				// If it is not set initially, the browser will throw an error.  This will set it if it is not set yet.
				element.style.filter = 'progid:DXImageTransform.Microsoft.Alpha(opacity=' + opacity + ')';
			}
		} else {
			element.style.opacity = opacity / 100;
		}
	}

	if (opacity < 100) {
		setTimeout(function () {
			fadeIn(element, opacity);
		}, rate);
	}
}

var isCancel=false;//是否取消上传
var uploadNum=0;//已成功上传文件
cancelUpload=function(){
    document.getElementById('imgCancelButton').style.visible='hidden';
    swfu.cancelUpload();
    /*var fileProgressID = "divFileProgress";
	var fileProgressWrapper = document.getElementById(fileProgressID);
	var fileProgressElement = fileProgressWrapper.firstChild;
    fileProgressElement.childNodes[2].innerHTML = '上传已停止！';*/
    isCancel=true;
}
setUploadNumber=function(num){
    document.getElementById("lgdUploadNumber").innerHTML="文件上传(已上传<span id='spNumber'>"+num+"</span>个文件)";
}
getFileName=function(filePath){
    var i=0;
    if(filePath.indexOf('/')==-1){
        i=filePath.lastIndexOf('\\');
    }else{
        i=filePath.lastIndexOf('/');
    }
    var j=filePath.lastIndexOf('.');
    var fileName=filePath.substring(i+1,j);
    return fileName;
}
setBackground=function(obj,color){
    return function(){
        setBackgroundWithParams(obj,color);
    }
}
setBackgroundWithParams=function(obj,color){
    obj.style.backgroundColor=color;
    obj.style.border="1px";
    obj.style.borderColor="red";
    
}
/* ******************************************
 *	FileProgress Object
 *	Control object for displaying file info
 * ****************************************** */
function FileProgress(file, targetID) {
	this.fileProgressID = "divFileProgress";

	this.fileProgressWrapper = document.getElementById(this.fileProgressID);
	if (!this.fileProgressWrapper) {
		this.fileProgressWrapper = document.createElement("div");
		this.fileProgressWrapper.className = "progressWrapper";
		this.fileProgressWrapper.id = this.fileProgressID;

		this.fileProgressElement = document.createElement("div");
		this.fileProgressElement.className = "progressContainer";

		var progressCancel = document.createElement("a");
		progressCancel.className = "progressCancel";
		progressCancel.href = "#";
		progressCancel.id = "imgCancelButton";
		progressCancel.attachEvent("onclick", cancelUpload); 
		progressCancel.style.visibility = "hidden";
		progressCancel.appendChild(document.createTextNode(" "));

		var progressText = document.createElement("div");
		progressText.className = "progressName";
		progressText.appendChild(document.createTextNode(file.name));

		var progressBar = document.createElement("div");
		progressBar.className = "progressBarInProgress";

		var progressStatus = document.createElement("div");
		progressStatus.className = "progressBarStatus";
		progressStatus.innerHTML = " ";

		this.fileProgressElement.appendChild(progressCancel);
		this.fileProgressElement.appendChild(progressText);
		this.fileProgressElement.appendChild(progressStatus);
		this.fileProgressElement.appendChild(progressBar);

		this.fileProgressWrapper.appendChild(this.fileProgressElement);

		document.getElementById(targetID).appendChild(this.fileProgressWrapper);
		fadeIn(this.fileProgressWrapper, 0);

	} else {
		this.fileProgressElement = this.fileProgressWrapper.firstChild;
		this.fileProgressElement.childNodes[1].firstChild.nodeValue = file.name;
	}

	this.height = this.fileProgressWrapper.offsetHeight;

}
FileProgress.prototype.setProgress = function (percentage) {
	this.fileProgressElement.className = "progressContainer green";
	this.fileProgressElement.childNodes[3].className = "progressBarInProgress";
	this.fileProgressElement.childNodes[3].style.width = percentage + "%";
};
FileProgress.prototype.setComplete = function () {
	this.fileProgressElement.className = "progressContainer blue";
	this.fileProgressElement.childNodes[3].className = "progressBarComplete";
	this.fileProgressElement.childNodes[3].style.width = "";

};
FileProgress.prototype.setError = function () {
	this.fileProgressElement.className = "progressContainer red";
	this.fileProgressElement.childNodes[3].className = "progressBarError";
	this.fileProgressElement.childNodes[3].style.width = "";

};
FileProgress.prototype.setCancelled = function () {
	this.fileProgressElement.className = "progressContainer";
	this.fileProgressElement.childNodes[3].className = "progressBarError";
	this.fileProgressElement.childNodes[3].style.width = "";

};
FileProgress.prototype.setStatus = function (status) {
	this.fileProgressElement.childNodes[2].innerHTML = status;
};

FileProgress.prototype.toggleCancel = function (show, swfuploadInstance) {
	this.fileProgressElement.childNodes[0].style.visibility = show ? "visible" : "hidden";
	if (swfuploadInstance) {
		var fileID = this.fileProgressID;
		this.fileProgressElement.childNodes[0].onclick = function () {
			swfuploadInstance.cancelUpload(fileID);
			return false;
		};
	}
};

MultiFileUpload.js

var uploadUrl='$!{request.uploadUrl}';//上传处理的url
var savePath='$!{request.savePath}';
var fileType='$!{request.fileType}';
//var postName='$request.postName';
var sizeLimit='$!{request.sizeLimit}';
var uploadLimit='$!{request.uploadLimit}';
//var buttonWidth='$!{request.buttonWidth}';
//var buttonHeight='$!{request.buttonHeight}';
var buttonText='$!{request.buttonText}';
var buttonAlign='$!{request.buttonAlign}';
var componentHeight='$!{request.componentHeight}';
var showThumbnail='$!{request.showThumbnail}'; //是否显示缩略图，一般用于图片上传，默认为false
var thumbnailScroll='$!{request.thumbnailScroll}';//缩略图部分是否显示滚动条
if(uploadUrl==''){
    //uploadUrl='/Commons/fileUpload.do';
    uploadUrl='/commons/paste.do?template=/multifileupload/data/upload.htm';
}
//if(postName=''){
//    postName= "Filedata";
//}
if(fileType==''){
    fileType='*.*';
}
if(uploadLimit==''){
    uploadLimit=0;
}
//if(buttonWidth==''){
//    buttonWidth=100;
//}
//if(buttonHeight==''){
//    buttonHeight=22;
//}
if(buttonText==''){
    buttonText='选 择 文 件';
}
if(buttonAlign==''){
    buttonAlign='left';
}
if(showThumbnail==''){
    showThumbnail=false;
}else{
    showThumbnail=true;
}
if(thumbnailScroll==''){
    thumbnailScroll=false;
}else{
    thumbnailScroll=true;
}

if(uploadUrl.indexOf('?')!=-1){
    uploadUrl=uploadUrl+'&savePath='+encodeURIComponent(savePath);
}else{
    uploadUrl=uploadUrl+'?savePath='+encodeURIComponent(savePath);
}

var swfu;
window.onload = function () {
	swfu = new SWFUpload({
		upload_url: uploadUrl,
		file_size_limit : sizeLimit,
		file_types : fileType,
		//file_types_description : "JPG Images",
		file_upload_limit : uploadLimit,    // Zero means unlimited

		file_queue_error_handler : fileQueueError,
		file_dialog_complete_handler : fileDialogComplete,
		upload_progress_handler : uploadProgress,
		upload_error_handler : uploadError,
		upload_success_handler : uploadSuccess,
		upload_complete_handler : uploadComplete,

		button_image_url : "/modules/commons/view/multifileupload/images/XPButtonNoText_160x22.png",
		button_placeholder_id : "spanButtonPlaceholder",
		button_width: 101,
		button_height: 22,
		button_text : buttonText,
		button_text_style : '.button { font-family: 华文行楷,宋体, Arial, sans-serif; font-size: 14pt; } .buttonSmall { font-size: 10pt; }',
		button_text_top_padding: 1,
		button_text_left_padding: 20,

		flash_url : "/modules/commons/js/swfupload/swfupload.swf",

		custom_settings : {
			upload_target : "divFileProgressContainer"
		},

		debug: false
	});
	
	if(thumbnailScroll){
        var divThumbnails=document.getElementById("thumbnails");
        var divContent=document.getElementById("content");
        divContent.style.width="400px";
        divThumbnails.style.height='200px';
        divThumbnails.style.overflowY="scroll";
        divThumbnails.style.border="solid 1px #DDF0DD";
    }
    document.getElementById("divButtonPlaceholder").style.textAlign=buttonAlign;
    if(componentHeight!=''){
        componentHeight=componentHeight.replace("px","");
        componentHeight=Number(componentHeight)-25;//去掉空隙和按钮高度
        document.getElementById("fsProgress").style.height=componentHeight+"px";
    }
}

其中MultiFileHandler.js是对于上传过程中各个事件的处理，MultiFileUpload.js是SWFUpload的使用，"$"符号开头的变量在实际使用过程中可以自由定制，另外在此还要提醒大家，。代码中的savePath变量是文件最后的保存路径，后台只要读取此变量保存到相应的位置即可。下面是后台代码：

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace WebApplication1
{
    public partial class FileUpload : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string path="";
            HttpPostedFile file= Request.Files["FileData"];
            string relationPath=Request["savePath"];
            if(relationPath!=string.Empty)
            {
                path=Server.MapPath("~/")+relationPath+"\\"+file.FileName;
            }
            file.SaveAs(path);
            Response.Write("success");
        }
    }
}

需要注意的是在后台一定要给出返回值（例如上面代码中Response.Write("success")）否则SWFUpload就不认为是上传完成。

下面的实际效果：

OK,今天就到这里吧。

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