Alchemy University 学习教程，Ethereum

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了解更多，请关注作者：https://twitter.com/bitc2024

这一期看文章的内容比较多，请各位自行查看。

Ethereum Features

Transactions Game

这里需要去下载一个钱包，创建一个钱包账户（注意不要导自己的助记词，直接新创建一个），注意最好用一个新的浏览器创建，不要在常用的浏览器创建（谷歌浏览器添加一个新账户创建即可）

官方这里有教程，可以看下，比较简单，我这里就不写了。

领完水后，需要进入官方discord群里，找一个钱包地址发送一些ETH过去，同时自己也要把自己刚刚创建的ETH地址发到这个频道去，内容包含：

1.写一个关于自己的有趣的事情，

2.钱包地址。

以下是频道：

https://discord.com/channels/1039895401832128532/1050240006574317618

点击上面链接后进不去频道的，需要在discord添加身份：

可以借鉴别人怎么发

随便找个地址发一些ETH给他就行。

注意用上面刚创建的钱包。

发送完第一节的游戏就完成了。

Reading Data from Ethereum

Activity: Query Ethereum

这块内容，主要是查看文章，不是真正做区块链的，看完就好了。

Ethereum Transactions

JSON-RPC Requests

1: Current Block Number

查看要求：

输入：

const provider = require('./provider');

async function getBlockNumber() {
    const ret = await provider.send({
        jsonrpc: "2.0",
        id: 1,
        method: "eth_blockNumber",
    });
    return ret.result;
}

module.exports = getBlockNumber;

点击运行。

2: Get Balance

查看要求：

输入：

const provider = require('./provider');

async function getBalance(address) {
    const ret = await provider.send({
        jsonrpc: "2.0",
        id: 1,
        method: "eth_getBalance",
        params: [address, "latest"],
    });
    return ret.result;
}

module.exports = getBalance;

点击运行。

3: Get Nonce

查看要求：

输入：

const provider = require('./provider');

async function getNonce(address) {
    const ret = await provider.send({
        jsonrpc: "2.0",
        id: 1,
        method: "eth_getTransactionCount",
        params: [address, "latest"],
    });
    return ret.result;
}

module.exports = getNonce;

点击运行。

4: Block Transactions

查看要求：

输入：

const provider = require('./provider');

async function getTotalTransactions(blockNumber) {
    const ret = await provider.send({
        jsonrpc: "2.0",
        id: 1,
        method: "eth_getBlockByNumber",
        params: [blockNumber, false], 
    });
    return ret.result.transactions.length;
}

module.exports = getTotalTransactions;

点击运行。

5: Total Wei

查看要求：

输入：

const provider = require('./provider');

async function getTotalBalance(addresses) {
    let reqs = [];
    for (let i = 0; i < addresses.length; i++) {
        reqs.push({
            jsonrpc: "2.0",
            id: 1,
            method: "eth_getBalance",
            params: [addresses[i], "latest"],
        });
    }
    const resps = await provider.send(reqs);
    let t = 0;
    for (let i = 0; i < resps.length; i++) {
        t = t + parseInt(resps[i].result);
    }
    return t;
}

module.exports = getTotalBalance;

点击运行。

Front-End Libraries

Intro to Ethers.js

1: Making Wallets

查看要求：

输入：

const ethers = require('ethers');
const { Wallet } = ethers;

// create a wallet with a private key
const wallet1 = new Wallet("0xf2f48ee19680706196e2e339e5da3491186e0c4c5030670656b0e0164837257d");

// create a wallet from mnemonic
const wallet2 = Wallet.fromMnemonic("plate lawn minor crouch bubble evidence palace fringe bamboo laptop dutch ice");

module.exports = {
    wallet1,
    wallet2,
}

点击运行。

2: Sign a Transaction

查看要求：

输入：

const ethers = require('ethers');
const { Wallet, utils } = ethers;
const { wallet1 } = require('./wallets');

const signaturePromise = wallet1.signTransaction({
    value: utils.parseEther('1', 'ether'),
    to: "0xdD0DC6FB59E100ee4fA9900c2088053bBe14DE92", 
    gasLimit: utils.parseUnits('21000', 'wei'),
});

module.exports = signaturePromise;

点击运行。

3: Connect to Ethereum

查看要求：

输入：

const { Wallet, utils, providers } = require('ethers');
const { ganacheProvider, PRIVATE_KEY } = require('./config');

const provider = undefined; 

const wallet = new Wallet(PRIVATE_KEY);

async function sendEther({ value, to }) {
    const rawTx = await wallet.signTransaction({ 
        value, to, 
        gasLimit: 0x5208,
        gasPrice: 0x3b9aca00 
    });

    const provider = new providers.Web3Provider(ganacheProvider);
    resp = await provider.sendTransaction(rawTx);
    return resp;
}

module.exports = sendEther;

点击运行。

4: Account Nonce

查看要求：

输入：

const { Wallet, utils, providers } = require('ethers');
const { ganacheProvider, PRIVATE_KEY } = require('./config');

const provider = new providers.Web3Provider(ganacheProvider);
const wallet = new Wallet(PRIVATE_KEY, provider);

async function sendEther({ value, to }) {
    return wallet.sendTransaction({ value, to });
}

module.exports = sendEther;

点击运行。

5: Find Balance

查看要求：

输入：

const { Wallet, providers } = require('ethers');
const { ganacheProvider } = require('./config');

const provider = new providers.Web3Provider(ganacheProvider);

function findMyBalance(privateKey) {
    const wallet = new Wallet(privateKey, provider);
    return wallet.getBalance();
}

module.exports = findMyBalance;

点击运行。

6: Charitable Donations

查看要求：

输入：

const { utils, providers, Wallet } = require('ethers');
const { ganacheProvider } = require('./config');

const provider = new providers.Web3Provider(ganacheProvider);

/**
 * Donate at least 1 ether from the wallet to each charity
 * @param   {string} a hex string private key for a wallet with 10 ETH
 * @param   {array} an array of ethereum charity addresses 
 *
 * @returns {Promise} a promise that resolves after all donations have been sent
 */
async function donate(privateKey, charities) {
    const wallet = new Wallet(privateKey, provider);
    let resps = [];
    nonce = await wallet.getTransactionCount();
    for (let i = 0; i < charities.length; i++) {
        const rawTx = await wallet.signTransaction({
            value: utils.parseEther('1', 'ether'),
            to: charities[i],
            gasLimit: utils.parseUnits('21000', 'wei'),
            nonce: nonce + i
        });
        resps.push(provider.sendTransaction(rawTx));
    }

    return Promise.all(resps);
}

module.exports = donate;

点击运行。

Where is the Ether?

1: Where is the Ether?

查看要求：

输入：

const { providers } = require('ethers');
const { ganacheProvider } = require('./config');

const provider = new providers.Web3Provider(ganacheProvider);

/**
 * Given an ethereum address find all the addresses
 * that were sent ether from that address
 * @param {string} address - The hexidecimal address for the sender
 * @async
 * @returns {Array} all the addresses that receieved ether
 */
async function findEther(address) {
    let addrs = [];
    let blockNum = await provider.getBlockNumber();
    for (let i = 0; i <= blockNum; i++) {
        let block = await provider.getBlockWithTransactions(i);
        block.transactions.forEach((tx) => {
            if (tx.from === address) {
                addrs.push(tx.to);
            }
        });
    }
    return addrs;
}

module.exports = findEther;

点击运行。

以上，Ethereum，课程学习完成。

未完待续……

了解更多，请关注作者：https://twitter.com/bitc2024

https://mirror.xyz/bible666.eth/X3VB59DNaNU37nTwsKOFwEUPZvEtuzbM0GJlMkK8x40