NodeJS gm调整大小并管道响应

Is there a way of piping the resized image to my express response?

有没有办法将调整大小的图像用于表达我的快速反应？

Something along the lines of:

有点像：

var express = require('express'),
    app = express.createServer();

app.get('/', function(req, res){

    gm('images/test.jpg')
        .resize(50,50)
        .stream(function streamOut (err, stdout, stderr) {
            if (err) return finish(err);
            stdout.pipe(res.end, { end: false }); //suspect error is here...
            stdout.on('end', function(){res.writeHead(200, { 'Content-Type': 'ima    ge/jpeg' });});
            stdout.on('error', finish);
            stdout.on('close', finish);
    });
});

app.listen(3000);

This unfortunately causes an error...
Pretty sure I've got some syntax wrong.

不幸的是，这会导致错误...很确定我的语法有些错误。

2 个解决方案

#1

your question actually helped me get the answer for the same issue. How it worked for me:

你的问题实际上帮助我得到了同样问题的答案。它对我有用：

    var express = require('express'),
    app = express.createServer();

app.get('/', function(req, res, next){

    gm('images/test.jpg')
        .resize(50,50)
        .stream(function streamOut (err, stdout, stderr) {
            if (err) return next(err);
            stdout.pipe(res); //pipe to response

            // the following line gave me an error compaining for already sent headers
            //stdout.on('end', function(){res.writeHead(200, { 'Content-Type': 'ima    ge/jpeg' });}); 

            stdout.on('error', next);
    });
});

app.listen(3000);

I removed all reference to finish function as it's not defined and sent the error to express error handler. Hope it helps someone. i also would like to add i'm using express 3, so creating the server is slightly different.

我删除了所有对finish函数的引用，因为它没有定义，并发送错误来表示错误处理程序。希望它可以帮到某人。我也想添加我使用快递3，所以创建服务器略有不同。

#2

You get the error because you want to write to res after you've piped the image. Try setting the headers before you pipe your image:

您收到错误是因为您想在管道传输图像后写入res。在管道图像之前尝试设置标题：

var express = require('express'),
    app = express.createServer();

app.get('/', function(req, res){

  res.set('Content-Type', 'image/jpeg'); // set the header here

  gm('images/test.jpg')
    .resize(50,50)
    .stream(function (err, stdout, stderr) {
      stdout.pipe(res)
    });
});

app.listen(3000);

#1