从角度脚本中获取$ _FILES ['file'] ['name']

Question

我想使用API​​使用Ionic 3 Angular 5上传照片。但是我无法从客户端到服务器端获取$ _FILES ['file'] ['name']。

    uploadPhoto2() {
let loader = this.loadingCtrl.create({
    spinner: 'crescent',
    dismissOnPageChange: true
});

loader.present();
this.group_id = 0;
this.media.tags = this.hashes;
this.media.img = this.image;
this.userData.uploadPhoto(this.media,this.group_id) 
.map(res => res.json())
.subscribe(data => {
    loader.dismiss(); 
    console.log(this.media);
    if (data.success) {
        swal({
            icon: "success",
            text: data.message,
            buttons: {
                visible: false
            }
        });
    }
    else {
        swal({
            icon: "error",
            text: data.error,
            buttons: {
                visible: false
            }
        });
    }
},
err => {
    loader.dismiss();
    alert('An error occurred, please check your internet connection');
});
   }

我想将其发送到api，apo可以正常工作，我做了回显，但没有显示回显$ _FILES ['file'] ['name']; exit;如何将其发送到服务器端？