ethers的合约函数allowance和approve的使用_ethers.js, 停止监听approve事件

一、查看allowance

 const provider = new providers.JsonRpcProvider(rpcUrl);
      console.log(provider);
      const wallet = new Wallet(privateKey, provider);
      // const connectWallet = wallet.connect(provider);
      if (tokenaddress === ethers.constants.AddressZero) {
        return;
      }
      const tokenContract = new Contract(tokenaddress, tokenabi, wallet);
      const address = await wallet.getAddress();
      const allowance = await tokenContract.allowance(address, bridgeaddress);

第一次查看是0； 

二、调用函数approve

 const approveTx = await tokenContract.approve(
          bridgeaddress,
          ethers.constants.MaxUint256,
          {
            gasPrice: await wallet.provider.getGasPrice()