JS与PHP实现文件上传：FormData与Base64方案详解

<form name="form1" id="form1">
   <input type="text" name="name" value="fdipzone">
   <input type="text" name="gender" value="male">
</form>

var form = document.getElementById('form1');
var formdata = new FormData(form);

var formdata = new FormData();
formdata.append('name','fdipzone');
formdata.append('gender','male');

<input type="file"
    :style="{display: 'none'}"
    ref="input" @change="selectedFile"
/>
<button @click="upload">上传</button>

methods: {
  triggerSelect () {
   this.$refs.input.click()
  },
  selectedFile (e) {
   console.log(e.target.files[0])
   //根据项目需求做具体处理，比如说获取文件名
  },
  async upload () {
   //如果不需要用到上传后的返回值可以把 async...await 语法去掉
   let files = this.$refs.input.files;
   if(files.length > 0) {
    let form = new FormData();
    form.append('file', files[0])
    let data = await new Promise((resolve, reject) => {
      axios({
       url: '',
       method: 'post',
       data: form
      })
       .then(res => {
        resolve(res)
       })
       .catch(err => {
        reject(err)
       })
     })
   }
  }
}

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
 <head>
 <meta http-equiv="content-type" content="text/html; charset=utf-8">
 <title> FormData Demo </title>
 </head>
 <body>
  <form name="form1" id="form1">
    <p>name:<input type="text" name="name" ></p>
    <p>gender:<input type="radio" name="gender" value="1">male <input type="radio" name="gender" value="2">female</p>
    <p>photo:<input type="file" name="photo" id="photo"></p>
    <p><input type="button" name="b1" value="submit" onclick="fsubmit()"></p>
  </form>
  <div id="result"></div>
 <script src="https://code.jquery.com/jquery-1.11.0.min.js"></script>
 <script type="text/javascript">
  function fsubmit(){
    var data = new FormData($('#form1')[0]);
    $.ajax({
      url: 'server.php',
      type: 'POST',
      data: data,
      dataType: 'JSON',
      cache: false,
      processData: false, //不处理发送的数据，因为data值是FormData对象，不需要对数据做处理
      contentType: false  //不设置Content-type请求头
    }).done(function(ret){
      if(ret['isSuccess']){
        var result = '';
        result += 'name=' + ret['name'] + '<br>';
        result += 'gender=' + ret['gender'] + '<br>';
        result += '<img src="' + ret['photo'] + '" width="100">';
        $('#result').html(result);
      }else{
        alert('提交失敗');
      }
    });
    return false;
  }
 </script>
</body>
</html>

<?php
$name = isset($_POST['name'])? $_POST['name'] : '';
$gender = isset($_POST['gender'])? $_POST['gender'] : '';
$filename = time().substr($_FILES['photo']['name'], strrpos($_FILES['photo']['name'],'.'));
$response = array();
if(move_uploaded_file($_FILES['photo']['tmp_name'], $filename)){
  $response['isSuccess'] = true;
  $response['name'] = $name;
  $response['gender'] = $gender;
  $response['photo'] = $filename;
}else{
  $response['isSuccess'] = false;
}
echo json_encode($response);
?>

// -------- 将以base64的图片url数据转换为Blob --------
function convertBase64UrlToBlob(urlData, filetype){
    //去掉url的头，并转换为byte
    var bytes = window.atob(urlData.split(',')[1]);
    //处理异常,将ascii码小于0的转换为大于0
    var ab = new ArrayBuffer(bytes.length);
    var ia = new Uint8Array(ab);
    var i;
    for (i = 0; i < bytes.length; i++) {
      ia[i] = bytes.charCodeAt(i);
    }
    return new Blob([ab], {type : filetype});
}
$input.on('change', function (e) {
    var input = $input.get(0);
    var files = input.files || [];
    if (files.length === 0) {
      return;
    }
    console.log('选中 ' + files.length + ' 个文件');
    // 遍历选中的文件，预览、上传
    $.each(files, function (key, file) {
      var filename = file.name || '';
      var fileType = file.type || '';
      var reader = new FileReader();
      // onload事件
      reader.onload = function (e) {
        var base64 = e.target.result || this.result;
        var formData = new FormData();
        formData.append("upload_file", convertBase64UrlToBlob(base64, fileType), filename);
        var xhr = new XMLHttpRequest();
        // 开始上传
        xhr.open('POST', uploadImgUrl, true);
        // 发送数据
        xhr.send(formData);
      });
      reader.readAsDataURL(file);
    });
});

.box{
 background-image: url("data:image/jpg;base64,/9j/4QMZR...");
}

<img src="data:image/jpg;base64,/9j/4QMZR..." />