HTML5 文件域+FileReader 读取文件并上传到服务器(三)

一、读取文件为blob并上传到服务器

HTML

<div class="container">
    <!--读取要上传的文件-->
    <input type="file" id="file"  />
    <input type="button" id="btn1" value="点击上传" onclick="uploadClick();" />
</div>

//读取图片实例,并上传到服务器
var fileBox = document.getElementById('file');
fileBox.onchange = function () {
    //获取选择文件的数组
    var fileList = fileBox.files;
    for (var i = 0; i < fileList.length; i++) {
        var file = fileList[i];
        uploadFile(file);
    }
}
//关键代码上传到服务器
function uploadFile(file) {
    var reader = new FileReader();
    reader.readAsArrayBuffer(file);
    reader.onload = function () {
        var blob = new Blob([reader.result]);
        //提交到服务器
        var fd = new FormData();
        fd.append('file', blob);
        var ext = file.name.substring(file.name.lastIndexOf('.'));
        fd.append('extention', ext);
        fd.append('maxsize', 1024*1024*4);//Asp.net 默认一次上传最大4MB
        fd.append('isClip', -1);
        var xhr = new XMLHttpRequest();
        xhr.open('post', '../ashx/upload.ashx', true);
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                var data = eval('(' + xhr.responseText + ')');
                console.info(data);
                if (data.success) {
                    //上传成功
                    var imgName = data.msg;
                    alert(imgName);
                } else {
                    alert(data.msg);
                }
            }
        }
        //开始发送
        xhr.send(fd);
    }
}

后台C#处理关键代码：

//接收文件
HttpRequest req = _Context.Request;
string newname = _fileInfo.CreateNewName(newExtention);
//接收二级制数据并保存
Stream stream = _PostedFile.InputStream;
byte[] dataOne = new byte[stream.Length];
stream.Read(dataOne, 0, dataOne.Length);
FileStream fs = new FileStream(_fileInfo.TempFile + newname, FileMode.Create, FileAccess.Write);
try
{
    fs.Write(dataOne, 0, dataOne.Length);
}
finally
{
    fs.Close();
    stream.Close();
}
return newname;

二、读取图片文件，并上传到服务器

HTML

<div class="container">
    <!--图片类型验证方法1-->
    <input type="file" id="file" accept="image/*" />
    <input type="button" id="btn1" value="点击上传" onclick="uploadClick();" />
    <h4>选择文件如下:</h4>
    <img src="" id="img1" />
</div>

JS：

//读取图片实例,并上传到服务器
var fileBox = document.getElementById('file');
fileBox.onchange = function () {
    //获取选择文件的数组
    var fileList = fileBox.files;
    for (var i = 0; i < fileList.length; i++) {
        var file = fileList[i];
        //图片类型验证第二种方式
        if (/image\/\w+/.test(file.type))
            readFile(file);
        else
            console.log(file.name + ':不是图片');
    }
}
//读取二进制图片文件，并上传到服务器
function uploadClick() {
    var fileList = fileBox.files;
    for (var i = 0; i < fileList.length; i++) {
        var file = fileList[i];
        //图片类型验证第二种方式
        if (/image\/\w+/.test(file.type))
            uploadFile(file);
        else
            console.log(file.name + ':不是图片');
    }
}
//关键代码上传到服务器
function uploadFile(file) {
    var reader = new FileReader();
    reader.readAsArrayBuffer(file);
    reader.onload = function () {
        var blob = new Blob([reader.result], { type: 'image/jpg' });
        //提交到服务器
        var fd = new FormData();
        fd.append('file', blob);
        var ext = file.name.substring(file.name.lastIndexOf('.'));
        fd.append('extention', ext);
        fd.append('isClip', -1);
        var xhr = new XMLHttpRequest();
        xhr.open('post', '../ashx/upload.ashx', true);
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                var data = eval('(' + xhr.responseText + ')');
                console.info(data);
                if (data.success) {
                    //上传成功
                    var imgName = data.msg;
                    alert(imgName);
                } else {
                    alert(data.msg);
                }
            }
        }
        //开始发送
        xhr.send(fd);
    }
}
//读取图片内容 为DataURL
function readFile(file) {
    var reader = new FileReader();
    reader.readAsDataURL(file);
    reader.onload = function (e) {
        var result = reader.result;
        $('.container blockquote').text(result);
        $('#img1').attr('src', result)
    }
}