TRC-20事件监听

Tronweb示例:
使用tronweb的watch方法监听智能合约方法发出的事件，可以定义一个回调函数来处理事件，当事件发生时，回调函数会被触发。下面的示例是监听主链上的USDT-TRC20合约的Transfer事件。

const trc20ContractAddress = "TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"; //mainnet USDT contract
let contract = await tronWeb.contract().at(trc20ContractAddress);
//contract.[eventname].watch(callback)  eventname是要监听此合约事件的名称
await contract && contract.Transfer().watch((err, event) => {
  if(err)
    return console.error('Error with "Message" event:', err);
 
  console.group('New event received');
  console.log('- Contract Address:', event.contract);
  console.log('- Event Name:', event.name);
  console.log('- Transaction:', event.transaction);
  console.log('- Block number:', event.block);
  console.log('- Result:', event.result, '\n');
  console.groupEnd();
});