uniappx的websocket不能传纯的二进制流？

怎么一发送就报错"io.dcloud.uts.ArrayBuffer cannot be cast to java.lang.String" ，发文本没问题。代码如下：
        const Buf = new ArrayBuffer(24);  
        this.socketTask?.send({
          data: Buf,
          success: (res : any) => {
            console.log(res)
          },
          fail: (err : any) => {
            console.log(err)
          },
        } as SendSocketMessageOptions)