DownloadTask.onHeadersReceived

基础库 3.180.1 版本开始支持。

解释：监听下载的 HTTP Response Header 事件，一次连接只会触发一次，早于下载请求完成事件

方法参数

Function callback

callback 返回参数说明

示例

代码示例

• SWAN
• JS

<view>
    <button type="primary" bindtap="onHeadersReceived">监听 HTTP Response Header</button>
</view>

Page({
    onHeadersReceived() {      
        let downloadTask = swan.downloadFile({
            url: 'https://b.bdstatic.com/miniapp/assets/docs/sprddemofile-sample.pdf',
            header: {
                'content-type': 'application/json'
            },
            success: () => {
                console.log('downloadFile success');
            },
            fail: () => {
                console.log('downloadFile fail');
            },
            complete: () => {
                console.log('downloadFile complete');
            }
        });
        let cb = res => {
            swan.showModal({
                title: 'onHeadersReceived',
                content: JSON.stringify(res)
            });
        };
        downloadTask.onHeadersReceived(cb);
    }  
});