基于jQuery异步上传文件的例子

File

JavaScript代码：

$(document).ready(function () {
$("#uploadbutton").click(function () {
var filename = $("#file").val();

$.ajax({
type: "POST",
url: "addFile.do",
enctype: 'multipart/form-data',
data: {
file: filename
},
success: function () {
alert("Data Uploaded: ");
}
});
});
});

$(':file').change(function(){
    var file = this.files[0];
    name = file.name;
    size = file.size;
    type = file.type;
    //your validation
});

$(':button').click(function(){
    var formData = new FormData($('form')[0]);
    $.ajax({
        url: 'upload.php',  //server script to process data
        type: 'POST',
        xhr: function() {  // custom xhr
            myXhr = $.ajaxSettings.xhr();
            if(myXhr.upload){ // check if upload property exists
                myXhr.upload.addEventListener('progress',progressHandlingFunction, false); // for handling the progress of the upload
            }
            return myXhr;
        },
        //Ajax事件
        beforeSend: beforeSendHandler,
        success: completeHandler,
        error: errorHandler,
        // Form数据
        data: formData,
        //Options to tell JQuery not to process data or worry about content-type
        cache: false,
        contentType: false,
        processData: false
    });
});

function progressHandlingFunction(e){
    if(e.lengthComputable){
        $('progress').attr({value:e.loaded,max:e.total});
    }
}