DownloadTask.onHeadersReceived

Page({
    onHeadersReceived() {      
        swan.chooseImage({
            success: res => {
                let uploadTask = swan.uploadFile({
                    //开发者服务器 url
                    url: 'https://smartprogram.baidu.com/xxx',

                    // 要上传文件资源的路径
                    filePath: res.tempFilePaths[0],

                    name: 'myfile',
                    header: {
                        'content-type': 'application/json'
                    },
                    formData: {
                        'user': 'swan'
                    },
                    success: () =>{
                        console.log('uploadFile success');
                    },
                    fail: err => {
                        console.log('uploadFile fail');
                    }
                });

                let cb = res => {
                    swan.showModal({
                        title: 'onHeadersReceived',
                        content: JSON.stringify(res)
                    });
                };
                uploadTask.onHeadersReceived(cb);
            }
        })
    }  
});