javascript - 如何手动创建 multipart/form-data

Question

我们可以使用.formData()的 Body混合以返回 Chromium (Chrome) 60+ and Firefox 39+ 处数据的 FormData 表示形式

相关规范:

• 7.2 The Multipart Content-Type
• Returning Values from Forms: multipart/form-data

勘误表

• Clarification of Body package data algorithm with bytes, FormData and multipart/form-data MIME type #392
• Documenting de-facto handling of multipart/form-data form field file uploads #3040

相关

• Multipart HTTP response
• How to upload files in Web Workers when FormData is not defined

如何在客户端和服务器端使用 JavaScript 手动创建 multipart/form-data 以将 multipart/form-data 作为响应？

Answer 1

您可以像本例一样使用 XMLHttpRequest 手动创建 multipart/form-data。

function multiPost(method, url, formHash){
    var boundary = "nVenJ7H4puv"
    var body = ""
    for(var key in formHash){
        body += "--" + boundary
             + "\r\nContent-Disposition: form-data; name=" + formHash[key].name
             + "\r\nContent-type: " + formHash[key].type
             + "\r\n\r\n" + formHash[key].value + "\r\n"
    }
    body += "--" + boundary + "--\r\n"

    var xml = new XMLHttpRequest();
    xml.open(method, url)
    xml.setRequestHeader("Content-Type", "multipart/form-data; boundary=" + boundary)
    xml.setRequestHeader("Content-Length", body.length)
    xml.send(body)
}