Ajax上传文件到服务器

Ajax上传文件到服务器要怎么做？星辉小编来告诉大家。

上传文件是常要处理的事情，使用ajaxFileUpload.js处理比较方便，这里的ajaxFileUpload.js文件修改过的，

Html部分

<input type="file" id="fu_UploadFile" name="fu_UploadFile" value="" title="上传附件">
<input type="button" value="上传" onclick="upload()" />  

JS部分

        function upload() {
            var path = document.getElementById("fu_UploadFile").value;
            if ($.trim(path) == "") { alert("请选择要上传的文件"); return; }
            console.log("test");
            var result_msg = "";
            $.ajaxFileUpload({
                url: '/UpFile.ashx',  //这里是服务器处理的代码
                type: 'post',
                secureuri: false, //一般设置为false
                fileElementId: 'fu_UploadFile', // 上传文件的id、name属性名
                dataType: 'json', //返回值类型，一般设置为json、application/json
                data: {}, //传递参数到服务器
                success: function (data, status) {
                        if (data.Result) {
                            alert("文件成功处理完成!" + data.FileName);
                        } else {
                            alert("文件成功处理出错！原因：" + data.ErrorMessage);
                        }
                },
                error: function (data, status, e) {
                    alert("错误：上传组件错误，请检察网络!");
                }
            });
        }

服务器：

    /// <summary>
    /// UpFile 的摘要说明
    /// </summary>
    public class UpFile : IHttpHandler
    {
        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            UpFileResult result = new UpFileResult();
            try
            {
                HttpPostedFile _upfile = context.Request.Files["fu_UploadFile"];
            if (_upfile == null)
            {
                throw new Exception("请先选择文件！");
            }
            else
            {
                string fileName = _upfile.FileName;/*获取文件名： C:Documents and SettingsAdministrator桌面123.jpg*/
                string suffix = fileName.Substring(fileName.LastIndexOf(".") + 1).ToLower();/*获取后缀名并转为小写： jpg*/
                int bytes = _upfile.ContentLength;//获取文件的字节大小  
                //
                if (!(suffix == "jpg" || suffix == "gif" || suffix == "png"|| suffix == "jpeg"))
                    throw new Exception("只能上传JPE，GIF,PNG文件");
                if (bytes > 1024 * 1024*10)
                    throw new Exception("文件最大只能传10M");
                string newfileName = DateTime.Now.ToString("yyyyMMddHHmmss");
                string fileDir = HttpContext.Current.Server.MapPath("~/upfiles/");
                if (!Directory.Exists(fileDir))
                {
                    Directory.CreateDirectory(fileDir);
                }
                result.FileName = fileName;

　　　　　　　　　　　　string saveDir = fileDir + newfileName + "." + suffix;
　　　　　　　　　　　　result.FileURL = "~/upfiles/" + newfileName + "." + suffix;
                _upfile.SaveAs(result.FileURL);//保存图片  
                  
            }
            }
            catch (System.Exception ex)
            {
                result.Result = false;
                result.ErrorMessage = ex.Message;
            }
            context.Response.Write(JsonHelper.SerializeObject(result)); 
        }
        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
        public class UpFileResult   //: AshxCommonResult
        {
            public bool Result { get; set; }
            public string ErrorMessage { get; set; }
            public string FileName { get; set; }
            public string FileURL { get; set; }
        }

ajaxfileupload.js

jQuery.extend({    
    handleError: function (s, xhr, status, e) {
        // If a local callback was specified, fire it
        if (s.error) {
            s.error.call(s.context || s, xhr, status, e);
        }
        // Fire the global callback
        if (s.global) {
            (s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
        }
    },
    createUploadIframe: function(id, uri)
    {
            //create frame
            var frameId = 'jUploadFrame' + id;
            var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';
            if(window.ActiveXObject)
            {
                if(typeof uri== 'boolean'){
                    iframeHtml += ' src="' + 'javascript:false' + '"';

                }
                else if(typeof uri== 'string'){
                    iframeHtml += ' src="' + uri + '"';
                }    
            }
            iframeHtml += ' />';
            jQuery(iframeHtml).appendTo(document.body);

            return jQuery('#' + frameId).get(0);            
    },
    createUploadForm: function(id, fileElementId, data)
    {
        //create form    
        var formId = 'jUploadForm' + id;
        var fileId = 'jUploadFile' + id;
        var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');    
        if(data)
        {
            for(var i in data)
            {
                jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);
            }            
        }        
        var oldElement = jQuery('#' + fileElementId);
        var newElement = jQuery(oldElement).clone();
        jQuery(oldElement).attr('id', fileId);
        jQuery(oldElement).before(newElement);
        jQuery(oldElement).appendTo(form);        
        //set attributes
        jQuery(form).css('position', 'absolute');
        jQuery(form).css('top', '-1200px');
        jQuery(form).css('left', '-1200px');
        jQuery(form).appendTo('body');        
        return form;
    },
    ajaxFileUpload: function(s) {
        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout        
        s = jQuery.extend({}, jQuery.ajaxSettings, s);
        var id = new Date().getTime()        
        var form = jQuery.createUploadForm(id, s.fileElementId, (typeof(s.data)=='undefined'?false:s.data));
        var io = jQuery.createUploadIframe(id, s.secureuri);
        var frameId = 'jUploadFrame' + id;
        var formId = 'jUploadForm' + id;        
        // Watch for a new set of requests
        if ( s.global && ! jQuery.active++ )
        {
            jQuery.event.trigger( "ajaxStart" );
        }            
        var requestDone = false;
        // Create the request object
        var xml = {}   
        if ( s.global )
            jQuery.event.trigger("ajaxSend", [xml, s]);
        // Wait for a response to come back
        var uploadCallback = function(isTimeout)
        {            
            var io = document.getElementById(frameId);
            try 
            {                
                if(io.contentWindow)
                {
                     xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
                     xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
                     
                }else if(io.contentDocument)
                {
                     xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
                    xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
                }                        
            }catch(e)
            {
                jQuery.handleError(s, xml, null, e);
            }
            if ( xml || isTimeout == "timeout") 
            {                
                requestDone = true;
                var status;
                try {
                    status = isTimeout != "timeout" ? "success" : "error";
                    // Make sure that the request was successful or notmodified
                    if ( status != "error" )
                    {
                        // process the data (runs the xml through httpData regardless of callback)
                        var data = jQuery.uploadHttpData( xml, s.dataType );    
                        // If a local callback was specified, fire it and pass it the data
                        if ( s.success )
                            s.success( data, status );    
                        // Fire the global callback
                        if( s.global )
                            jQuery.event.trigger( "ajaxSuccess", [xml, s] );
                    } else
                        jQuery.handleError(s, xml, status);
                } catch(e) 
                {
                    status = "error";
                    jQuery.handleError(s, xml, status, e);
                }
                // The request was completed
                if( s.global )
                    jQuery.event.trigger( "ajaxComplete", [xml, s] );
                // Handle the global AJAX counter
                if ( s.global && ! --jQuery.active )
                    jQuery.event.trigger( "ajaxStop" );
                // Process result
                if ( s.complete )
                    s.complete(xml, status);
                jQuery(io).unbind()
                setTimeout(function()
                                    {    try 
                                        {
                                            jQuery(io).remove();
                                            jQuery(form).remove();                                                
                                        } catch(e) 
                                        {
                                            jQuery.handleError(s, xml, null, e);
                                        }                                    
                                    }, 100)
                xml = null
            }
        }
        // Timeout checker
        if ( s.timeout > 0 ) 
        {
            setTimeout(function(){
                // Check to see if the request is still happening
                if( !requestDone ) uploadCallback( "timeout" );
            }, s.timeout);
        }
        try 
        {
            var form = jQuery('#' + formId);
            jQuery(form).attr('action', s.url);
            jQuery(form).attr('method', 'POST');
            jQuery(form).attr('target', frameId);
            if(form.encoding)
            {
                jQuery(form).attr('encoding', 'multipart/form-data');                  
            }
            else
            {    
                jQuery(form).attr('enctype', 'multipart/form-data');            
            }            
            jQuery(form).submit();
        } catch(e) 
        {            
            jQuery.handleError(s, xml, null, e);
        }        
        jQuery('#' + frameId).load(uploadCallback    );
        return {abort: function () {}};    
    },
    uploadHttpData: function( r, type ) {
        var data = !type;
        data = type == "xml" || data ? r.responseXML : r.responseText;
        // If the type is "script", eval it in global context
        if ( type == "script" )
            jQuery.globalEval( data );
        // Get the JavaScript object, if JSON is used.
        if ( type == "json" )
            var reg = /<pre.+?>(.+)</pre>/g;  
            var result = data.match(reg);  
            data = RegExp.$1;
            eval( "data = " + data );
        // evaluate scripts within html
        if ( type == "html" )
            jQuery("<div>").html(data).evalScripts();
        return data;
    }
})