ton 增加event的实例

// User purchase msg
message BuyMsg {
  number: Int as uint32;
}
message BuyEvent {
  // Purchase address
  buy: Address;
  // Order number, unique, used to prevent duplicate purchases
  orderNumber: Int as uint32;
}
 // User places a bet
 // add emit event
 receive(msg: BuyMsg){
    // Trigger event
    let eventLog:BuyEvent=BuyEvent{
        buy: ctx.sender,
        orderNumber: msg.number
      };
    send(SendParameters{
      to: self.owner,
      value: 0,
      mode: SendPayGasSeparately + SendIgnoreErrors,
      bounce: false,
      body: eventLog.toCell()
    }
    );
    // Return Gas balance
    let str:StringBuilder = beginComment().concat("good luck order:").concat(msg.orderNumber.toString());
    self.reply(str.toCell());
  }