<aside> 💡 如何在浏览器Console环境里，通过MetaMask钱包，使用JavaScript程序，获取Ethereum链上数据并发送交易

</aside>

Metamask钱包

1. 安装：https://metamask.io/
2. 生成钱包
3. 文档：https://docs.metamask.io/guide/

Ethereum测试网

1. 加入测试网：Goerli
2. 水龙头领币：https://faucets.chain.link/goerli
3. 测试网浏览器：https://goerli.etherscan.io/

JavaScript编程

1. 区块链

   const block = await ethereum.request({
     method: 'eth_getBlockByNumber',
     params: [
       'latest',
       true
     ]
   });
   console.log(block);
   

2. 账户

   // 查看地址
   const accounts = await ethereum.request({method: 'eth_requestAccounts'});
   console.log(accounts);
   const account = accounts[0];
   console.log(account);
   
   // 查看余额
   const balance = await ethereum.request({
     method: 'eth_getBalance',
     params: [
       account,
       'latest'
     ]
   });
   console.log(balance);
   console.log(Number(balance));
   console.log(Number(balance)/1e18);
   

3. 转账

   // 发起交易
   const txHash = await ethereum.request({
     method: 'eth_sendTransaction',
     params: [{
       from: account,
       to: '0x0F4b61d75Afbe799324aaE924199226875aFD4E4',
       value: Number(0.05 * 1e18).toString(16),
     }],
   });
   console.log(txHash);
   
   // 查看交易
   const tx = await ethereum.request({
     method: 'eth_getTransactionByHash',
     params: [txHash]
   });
   console.log(tx);
   
   // 查看交易回执
   const txReceipt = await ethereum.request({
     method: 'eth_getTransactionReceipt',
     params: [txHash]
   });
   console.log(txReceipt);
   

4. 更多API：https://eth.wiki/json-rpc/API