如何以 Express 方式传输响应？

我一直在尝试让一个快速应用程序以流形式发送响应。

var Readable = require('stream').Readable;
var rs = Readable();


app.get('/report', function(req,res) {
    
    res.statusCode = 200;
    res.setHeader('Content-type', 'application/csv');
    res.setHeader('Access-Control-Allow-Origin', '*');

    // Header to force download
    res.setHeader('Content-disposition', 'attachment; filename=Report.csv');

    
    rs.pipe(res);

    rs.push("USERID,NAME,FBID,ACCOUNT,SUBSCRIPTION,PRICE,STATE,TIMEPERIOD\n");

    for (var i = 0; i < 10; i++) {
        rs.push("23,John Doe,1234,500,SUBSCRIPITON,100,ACTIVE,30\n");
    }

    rs.push(null);
});      

当我用“rs.pipe(process.stdout)”替换“rs.pipe(res)”时，它确实会在控制台中打印。但如何让它在 Express 应用程序中工作呢？

Error: not implemented
    at Readable._read (_stream_readable.js:465:22)
    at Readable.read (_stream_readable.js:341:10)
    at Readable.on (_stream_readable.js:720:14)
    at Readable.pipe (_stream_readable.js:575:10)
    at line "rs.pipe(res);"

您不需要可读的流实例，只需使用res.write():

res.write("USERID,NAME,FBID,ACCOUNT,SUBSCRIPTION,PRICE,STATE,TIMEPERIOD\n");

for (var i = 0; i < 10; i++) {
    res.write("23,John Doe,1234,500,SUBSCRIPITON,100,ACTIVE,30\n");
}

res.end();

这是有效的，因为在 Express 中，res是基于Node自己的http.serverResponse https://nodejs.org/api/http.html#http_class_http_serverresponse，所以它继承了它的所有方法（比如write https://nodejs.org/api/http.html#http_response_write_chunk_encoding_callback).