无法读取Web套接字中未定义的属性“发送”

Question

我正在尝试使用网络套接字上传文件。但是我收到错误“无法读取未定义的属性'发送'” 。

  

component.ts

ws_scheme = window.location.protocol == "https:" ? "wss" : "ws";
ws_path = this.ws_scheme + '://' + window.location.host + 
"/api/chat/stream/";
newWindow = null;
ws = new ReconnectingWebSocket(this.ws_path);

fileSelected($event){
let file = $event.target.files[0];
this.file = file;

if (file) {
  let fileSize = 0;
  if (file.size > 1024 * 1024)
    this.fileSize = (Math.round(file.size * 100 / (1024 * 1024)) / 100).toString() + 'MB';
  else
    this.fileSize = (Math.round(file.size * 100 / 1024) / 100).toString() + 'KB';

    console.log(this.ws);
    console.log(this.ws.url);

  }
}

sendRequest() {
let blob = 
(<HTMLInputElement>document.getElementById('fileToUpload')).files[0];
    const BYTES_PER_CHUNK = 104857600; // 1MB chunk sizes.
    const SIZE = blob.size;
    let start = 0;
    let end = BYTES_PER_CHUNK;

    while( start < SIZE ) {
        let chunk = blob.slice(start, end);
        this.uploadFile(chunk);
        start = end;
        end = start + BYTES_PER_CHUNK;
    }
    this.openNewWindow();
}

executeAsync(func) {
setTimeout(func, 0);
}
uploadFile(blobFile) {
this.executeAsync(function() {
this.ws.send(blobFile);
console.log("after sending via websocket...")
});
}

我能够打开和关闭连接，但无法发送数据。错误发生在 this.ws.send（blobFile）中。该如何解决？