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如何在typescript中通过websocket接收浮点数据

binary-data floating-point websocket typescript

4

Eben Kadile · 技术社区 · 7 年前

我知道没有办法像字符串那样轻松地发送和接收浮动。但是,如果我这样设置websocket:

ws = new WebSocket(address);
ws.binaryType = 'blob';

我应该能够将传入的bytestring转换为float。将float转换为bytestring并在服务器端发送它们很容易。

我能找到的最接近答案是 this . 然而,我发现 e.target.result 没有定义。我试着用 e.target

this ,将uint数组转换为浮点数。但是如果我有这样的东西

ws.onmessage = function(event){
  //do something with event.data
}

我需要了解如何与他人合作 event.data 当它不仅仅是一个字符串时 here .

1 回复 | 直到 7 年前

1

3

Eben Kadile 7 年前

改编后 this answer 和 this answer ,我提出了以下解决方案:

//open the socket and set the data type to blob
let socket = new WebSocket(address);
socket.binaryType = 'blob';

//we will store 6 positions at a time
let positions = new Float32Array(18);

//helpers
let buffer = new ArrayBuffer(4);
let view = new DataView(buffer);

//say hello
socket.onopen = function(){
  socket.send('Hello');
};

//keep track of where we are in the position array
let posIndex = 0;

socket.onmessage = function(msg){
  //convert message to Uint8 array
  let bitArray = new Uint8Array(msg.data);
  for(let i = 0; i < 3; i++){
    for(let j = 0; j < 4; j++){
      //set the elements of the DataView equal to the bytes
      view.setUint8(j, bitArray[4*i + j]);
    }

    //update the positions
    if(posIndex < 5){
      positions[3*posIndex + i] = view.getFloat32(0);
      posIndex++;
    }
    else positions[15 + i] = view.getFloat32(0);
  }

  //this should log the positions as they come in
  paragraph.innerHTML = paragraph.innerHTML + ",("
                      + positions[posIndex] + ","
                      + positions[posIndex + 1] + ","
                      + positions[posIndex + 2] + ")";

  //the server won't send another position until it hears from the client
  socket.send('r');
};