废话不多说，直接贴代码
<input type="file" id="postFild" name="userfile" onchange="fileSelected(this);" />
function fileSelected(userfile) {
uploadFile(userfile);
}
function uploadFile(userfile) {
var fd = new FormData();
fd.append("userfile",userfile.files[0]);//文件追到到FormData
var xhr = new XMLHttpRequest();
xhr.upload.addEventListener("progress", uploadProgress, false);
xhr.addEventListener("load", uploadComplete, false);
xhr.addEventListener("error", uploadFailed, false);
xhr.addEventListener("abort", uploadCanceled, false);
xhr.open("POST", "文件上传地址");
xhr.send(fd);
}
//图片上传进度
function uploadProgress(evt) {
if (evt.lengthComputable) {
var percentComplete = Math.round(evt.loaded * 100 / evt.total);
console.log(percentComplete)
}else {
}
}
//图片上传完成
function uploadComplete(evt) {
var json = eval('(' + evt.target.responseText + ')');
//图片上传完成服务器相应
console.log(json)
}
function uploadFailed(evt) {
alert("上传失败");
}
function uploadCanceled(evt) {
// alert("已经取消上传");
}
