元问题是如何知道一个契约是为了萎缩还是为了主网络？

Question

我使用这段代码来检测元问题。

现在我正在使用ropsten，但我想知道元my如何知道我的合同只适用于ropsten？

window.addEventListener('load', async () => {
    // Modern dapp browsers...
    if (window.ethereum) {
        window.web3 = new Web3(ethereum);
        try {
            await ethereum.enable();
            var accounts= await web3.eth.getAccounts();
            var option={from: accounts[0] };
            var contract = new web3.eth.Contract(abi,address);
            const agiContract = new web3.eth.Contract(agiabi,agiContractAddress);

            const balance = await contract.methods.balanceOf(accounts[0]).call();
            const myDivs = await contract.methods.dividendsOf(accounts[0]).call();


            var supply = await contract.methods.totalSupply().call();
            var agiBalance = await contract.methods.totalAgiBalance().call();

            const agiAccountBalance = await agiContract.methods.balanceOf(accounts[0]).call();



            document.getElementById('agiAvailable').innerHTML = agiAccountBalance/100000000;
            document.getElementById('agiContractBalance').innerHTML = agiBalance/100000000 + ' AGI';
            document.getElementById('contractBalanceSnet').innerHTML = supply/100000000 + ' SNET';
            document.getElementById('snet-holding').innerHTML = balance/100000000;
            document.getElementById('myDividends').innerHTML = myDivs/100000000;
            document.getElementById('wallet').innerHTML = accounts;


            ethereum.on('accountsChanged', async (accounts) => {
              await ethereum.enable();
              var accounts= await web3.eth.getAccounts();
              var option={from: accounts[0] };
              var contract = new web3.eth.Contract(abi,address);
              const agiContract = new web3.eth.Contract(agiabi,agiContractAddress);

              const balance = await contract.methods.balanceOf(accounts[0]).call();
              const myDivs = await contract.methods.dividendsOf(accounts[0]).call();


              var supply = await contract.methods.totalSupply().call();
              var agiBalance = await contract.methods.totalAgiBalance().call();

              const agiAccountBalance = await agiContract.methods.balanceOf(accounts[0]).call();



              document.getElementById('agiAvailable').innerHTML = agiAccountBalance/100000000;
              document.getElementById('agiContractBalance').innerHTML = agiBalance/100000000;
              document.getElementById('contractBalanceSnet').innerHTML = supply/100000000;
              document.getElementById('snet-holding').innerHTML = balance/100000000;
              document.getElementById('myDividends').innerHTML = myDivs/100000000;
              document.getElementById('wallet').innerHTML = accounts;
            })
        } catch (error) {
            // User denied account access...
            console.log(error)
        }
    }
    // Legacy dapp browsers...
    else if (window.web3) {
        window.web3 = new Web3(web3.currentProvider);
        // Acccounts always exposed
        web3.eth.sendTransaction({/* ... */});
    }
    // Non-dapp browsers...
    else {
        document.getElementById('wallet').innerHTML = "Use Metamask on a Desktop or use TrustWallet on a mobile";
        document.getElementById('agiAvailable').innerHTML = "<a href='https://binance.com/' style='color:green'>BUY</a> ";
    }
});

Answer 1

var contract = new web3.eth.Contract(abi,address);
const agiContract = new web3.eth.Contract(agiabi,agiContractAddress);

只有在实现该功能的契约部署在contract上时，通过address进行的任何链上函数调用才能成功完成。

只有在实现该功能的契约部署在agiContract上时，通过agiContractAddress进行的任何链上函数调用才能成功完成。

这意味着您的程序可能在一个网络上成功运行，但在另一个网络上失败。

MetaMask不是这里的原因；您的输入地址是。

Answer 2

Metamask不知道您的合同只存在于Ropsten中。当您登录元问题时，您可以在下图的下拉列表中选择要使用的网络。

这是web3将与之交互的网络。您可以通过查看web3对象的网络id来检查正在使用的网络。您可以使用下面的代码来完成此操作。如果您的合同只适用于Ropsten，那么如果用户不在Ropsten上，您可能需要提出一个警告或建议来更改网络。

web3.version.getNetwork((err, netId) => {
  switch (netId) {
    case "1":
      console.log('This is mainnet')
      break
    case "2":
      console.log('This is the deprecated Morden test network.')
      break
    case "3":
      console.log('This is the ropsten test network.')
      break
    default:
      console.log('This is an unknown network.')
  }
})

这个答案的代码