Angular 2，用FileReader拆分大块二进制文件并发送到php

Question

我正在尝试创建一个服务，将一个大文件分成块并将其发送到重新组装它的php页面。

@Injectable()
export class FileSplitterService {
  private serviceName: String = "FileSplitterService";



  public file: File;
  public fileSize: number;

  private chunkSize: number = 64*1024;
  private offset: number = 0;

  constructor(private _http: Http) {
    console.log(this.serviceName + ' - constructor');
  }
  startSplit(event) {
    console.log(this.serviceName + ' - startSplit');

    /**
     * Initialize offset and file stuffs
     */
    this.file = event.files[0];
    this.fileSize = this.file.size;
    this.offset = 0;
    console.log(this.serviceName + ' - startSplit',this.file,this.fileSize,this.offset);
    /**
     * Start reading file
     */
    this.chunkReaderBlock();
  }

  readEventHandler(evt) {
    console.log(this.serviceName + ' - readEventHandler',evt);
    if (evt.target.error == null) {
      this.offset += evt.target.result.length;

      /**
       * send chunk
       *
       */
      this._http.post("https://10.134.77.77/web2/api/uploadFile.php",evt.target.result)
      .map(res => <any>res      )
      .subscribe(res=>{
        if (this.offset >= this.fileSize) {
          console.log(this.serviceName + ' - Done reading file');
        } else{
          // read next chunk
          console.log(this.serviceName + ' - readEventHandler -> read next chunk', this.offset);
          this.chunkReaderBlock();
        }
      });



    } else {
      console.log(this.serviceName + ' - Read error: ' + evt.target.error);
      return;
    }

  }

  chunkReaderBlock() {
    console.log(this.serviceName + ' - chunkReaderBlock', this.offset, this.chunkSize, this.file);
    var r: FileReader = new FileReader();
    var blob = this.file.slice(this.offset, this.chunkSize + this.offset);
    r.onload = (e) => {
      console.log(this.serviceName + ' - onload',e);
      this.readEventHandler(e)
    };

    r.readAsText(blob);
  }

}

我的第一个版本的服务适用于大文本文件，但是当我尝试使用FileReader的 readAsArrayBuffer 方法（而不是readAsText）来分割二进制文件（如视频）时会出现问题。看来，在第一次阅读之后，onLoad函数返回一个空的事件对象。 有人能帮我吗？感谢。