Asp.Net Mvc非同步上傳文件的方式

今天試了下mvc自帶的ajax，發現上傳文件時後端action接收不到文件， Request.Files和HttpPostedFileBase都接收不到。。。。。後來搜索了下才知道mvc自帶的Ajax不支持文件上傳，無奈之下只能用其他的方式第一種方式：通過　jquery的ajaxSubmit 》（ ...

今天試了下mvc自帶的ajax，發現上傳文件時後端action接收不到文件， Request.Files和HttpPostedFileBase都接收不到。。。。。後來搜索了下才知道mvc自帶的Ajax不支持文件上傳，無奈之下只能用其他的方式

第一種方式：通過　jquery的ajaxSubmit　　　---》（先引入jQuery腳本）需要引入jquery.form.min.js（可以通過NuGet下載）　　直接上代碼

@{
    Layout = null;
}

<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
    <script src="~/Scripts/jquery-1.10.2.min.js"></script>
    @*<script src="~/Scripts/jquery.unobtrusive-ajax.min.js"></script>*@  
    @*用了jquery.form.min.js可以不引用，即便引用了也沒關係不影響，但是引用了的話需要註意的是會發生兩次提交，在提交前執行return false即可，*@
    <script src="~/Scripts/jquery.form.min.js"></script>
</head>
<body>
    <div>
        <h3>mvc非同步上傳文件</h3>
        @using (Ajax.BeginForm("UpFileload", "AjaxFileUpload", new AjaxOptions
        {
            Confirm = "確認上傳嗎？",
            HttpMethod = "post",
            OnSuccess = "func",
        }, new { enctype = "multipart/form-data", id = "fileForm" }))
        {
            <input type="file" name="file" value="" />
            @*<button type="submit">非同步上傳</button>*@
            <button type="button">非同步上傳</button>
        }
    </div>
</body>
</html>
<script>
    //當按鈕被點擊時執行非同步提交
    $("button[type=button]").click(() => {
        //非同步提交
        $("#fileForm").ajaxSubmit({     
            url: "@Url.Action("UpFileload", "AjaxFileUpload")",
            type: "post",
            success: data => {
                alert(data);
            },
            error: () => {
                alert("出錯了");
            }
        });
    });
</script>

後端action代碼：

   /// <summary>
        /// 非同步文件上傳
        /// </summary>
        /// <param name="file">前端上傳的文件</param>
        /// <returns>文件路徑</returns>
        public ActionResult UpFileload(HttpPostedFileBase file)
        {
            //var myfile = Request.Files["file"]; //也可以拿到
            var path = $"/UploadFile/{Guid.NewGuid() + file.FileName}";
            file.SaveAs(Server.MapPath(path));      //保存文件
            return Content(path);
        }

jQuery的ajaxSubmit方法和ajax用法都差不多

第二種方式： $.ajaxFileUpload（{}）　　--->（先引入jQuery腳本）需要引入ajaxfileupload.js腳本　　（這個方法是之前在項目過中用過的，不過當時我記得從網上下載下來的ajaxfileupload腳本會提示出錯，好像是因為腳本里缺少什麼函數來著，忘記了，然後我按照搜索到的解決方法修改了腳本）

因為是之前寫的項目不是demo，代碼量有點多就不一一貼上代碼了，其實用法和第一種差不多，

 $.ajaxFileUpload({
            url: '@Url.Action("FileUpload", "Profile")',
            secureuri: false,
            fileElementId: 'btn_file',    //文件input標簽id
            data: null,
            success: function (data, status) {
                $.post("@Url.Action("MyData", "Profile")", null,
                    html => {
                        $("#mybody").children().remove();
                        $(html).appendTo("#mybody");
                    });
            },
            error: function (data, status, e) {
                console.log('Error')   
            }
        });

最後貼上修改後的ajaxfileupload.js腳本的源碼：

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;

        if(window.ActiveXObject) {
            var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
            if(typeof uri== 'boolean'){
                io.src = 'javascript:false';
            }
            else if(typeof uri== 'string'){
                io.src = uri;
            }
        }
        else {
            var io = document.createElement('iframe');
            io.id = frameId;
            io.name = frameId;
        }
        io.style.position = 'absolute';
        io.style.top = '-1000px';
        io.style.left = '-1000px';

        document.body.appendChild(io);

        return io
    },
    createUploadForm: function(id, fileElementId)
    {
        //create form
        var formId = 'jUploadForm' + id;
        var fileId = 'jUploadFile' + id;
        var form = $('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');
        var oldElement = $('#' + fileElementId);
        var newElement = $(oldElement).clone();
        $(oldElement).attr('id', fileId);
        $(oldElement).before(newElement);
        $(oldElement).appendTo(form);
        //set attributes
        $(form).css('position', 'absolute');
        $(form).css('top', '-1200px');
        $(form).css('left', '-1200px');
        $(form).appendTo('body');
        return form;
    },
    addOtherRequestsToForm: function(form,data)
    {
        // add extra parameter
        var originalElement = $('<input type="hidden" name="" value="">');
        for (var key in data) {
            name = key;
            value = data[key];
            var cloneElement = originalElement.clone();
            cloneElement.attr({'name':name,'value':value});
            $(cloneElement).appendTo(form);
        }
        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);
        if ( s.data ) form = jQuery.addOtherRequestsToForm(form,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
                    {
                        $(io).remove();
                        $(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 io = $('#' + frameId);
            var form = $('#' + formId);
            $(form).attr('action', s.url);
            $(form).attr('method', 'POST');
            $(form).attr('target', frameId);
            if(form.encoding)
            {
                form.encoding = 'multipart/form-data';
            }
            else
            {
                form.enctype = 'multipart/form-data';
            }
            $(form).submit();

        } catch(e)
        {
            jQuery.handleError(s, xml, null, e);
        }
        if(window.attachEvent){
            document.getElementById(frameId).attachEvent('onload', uploadCallback);
        }
        else{
            document.getElementById(frameId).addEventListener('load', uploadCallback, false);
        }
        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" )
        {
            // If you add mimetype in your response,
            // you have to delete the '<pre></pre>' tag.
            // The pre tag in Chrome has attribute, so have to use regex to remove
            var data = r.responseText;
            var rx = new RegExp("<pre.*?>(.*?)</pre>","i");
            var am = rx.exec(data);
            //this is the desired data extracted
            var data = (am) ? am[1] : "";    //the only submatch or empty
            eval( "data = " + data );
        }
        // evaluate scripts within html
        if ( type == "html" )
            jQuery("<div>").html(data).evalScripts();
        //alert($('param', data).each(function(){alert($(this).attr('value'));}));
        return data;
    }
})

View Code

感覺還是第一種比較舒服~~~不知道還有沒有更簡單好用的方式