Node.js io从1.0开始支持二进制流，是否有一个完整的例子专门用于图像

我是node.js和socket.io的初学者。io从1.0开始支持二进制流，是否有一个完整的示例专门用于将图像推送到客户端并在画布中显示？谢谢

谢谢，@sovente，在这篇1.0简介中，这是关于二进制支持的代码片段

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

我想知道如何在客户端处理缓冲区，代码如下：

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

 socket.on("image", function(image, buffer) {
     if(image)
     {
         console.log(" image: ");
         **// code to handle buffer like drawing with canvas**
     }

 });

---

这个解决方案有点复杂，但应该可以在Chrome、Firefox和IE10+中使用（Opera和Safari不太清楚）：

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

服务器端某处：

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

io.on('connection', function(socket){
    fs.readFile('/path/to/image.png', function(err, buffer){
        socket.emit('image', { buffer: buffer });
    });
});

socket.on('image', function(data) {
    var uint8Arr = new Uint8Array(data.buffer);
    var binary = '';
    for (var i = 0; i < uint8Arr.length; i++) {
        binary += String.fromCharCode(uint8Arr[i]);
    }
    var base64String = window.btoa(binary);

    var img = new Image();
    img.onload = function() {
        var canvas = document.getElementById('yourCanvasId');
        var ctx = canvas.getContext('2d');
        var x = 0, y = 0;
        ctx.drawImage(this, x, y);
    }
    img.src = 'data:image/png;base64,' + base64String;
});

下面是您在客户机上如何处理它：

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

io.on('connection', function(socket){
    fs.readFile('/path/to/image.png', function(err, buffer){
        socket.emit('image', { buffer: buffer });
    });
});

socket.on('image', function(data) {
    var uint8Arr = new Uint8Array(data.buffer);
    var binary = '';
    for (var i = 0; i < uint8Arr.length; i++) {
        binary += String.fromCharCode(uint8Arr[i]);
    }
    var base64String = window.btoa(binary);

    var img = new Image();
    img.onload = function() {
        var canvas = document.getElementById('yourCanvasId');
        var ctx = canvas.getContext('2d');
        var x = 0, y = 0;
        ctx.drawImage(this, x, y);
    }
    img.src = 'data:image/png;base64,' + base64String;
});

socket.on（'image'，函数（数据）{
var uint8Arr=新的Uint8Array（data.buffer）；
var二进制=“”；
对于（变量i=0；i

---

只需将您的canvasid替换为canvasid:）

就可以从socket.io 1.0开始发送二进制数据。

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

官方文件中不清楚如何发送和接收二进制数据。唯一的文件是：

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

var socket = new WebSocket('ws://localhost');
socket.binaryType = 'arraybuffer';
socket.send(new ArrayBuffer);

我建议您看看这个答案，在这里您可以找到服务器和客户端的代码实现（javascript、java）：

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

好的方面是，它也适用于Android

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});

---

干杯

我认为您只需要读取节点源上的blob，然后将其发送到套接字，所有侦听器都将接收blob。在客户端，我建议您在base64中对其进行编码（或者如果您确信不会出现cpu问题，则在服务器端对其进行编码），然后按照以下说明进行操作：谢谢，@CuriousGuy，但我总是收到错误“Uncaught TypeError:无法读取未定义的属性'buffer'，客户端没有图像。有任何建议吗？非常好。不知道为什么

Socket.io

文档只解释了服务器端。我以前从未听说过

Uint8Array

和

btoa

。谢谢。我在StackOverflow和--IMHO发现了这些函数/类，这是学习JavaScript的最佳场所：）对于在执行String.fromCharCode.apply时遇到“超过最大调用堆栈大小错误”的人，您可能希望从@mobz签出作为一种解决方法如何将此解决方案用于音频文件？

var fs = require('fs');
var io = require('socket.io')(3000);
io.on('connection', function(socket){
  fs.readFile('image.png', function(err, buf){
    // it's possible to embed binary data
    // within arbitrarily-complex objects
    socket.emit('image', { image: true, buffer: buf });
  });
});