君不见一个简单的东西没有一个好的流程去说明一下，折腾起人来那是相当的费劲
本文旨在让感兴趣的客官，能够快速体验到区块链dapp开发的流程，不对步骤做任何详细的解释
流程跑通后，再去学习，相信你会感觉更加良好
启动 Ganache
Ganache启动后会生成10个账号地址，如红色框便是第一个地址，记为账户地址A
同时请记住RPC SERVER地址，如红色箭头所示，记为服务器地址B
Ganache启动
切记：暂时不要关闭Ganache
环境创造
请确保安装了 node 和 npm （命令node -v以及命令npm -v查看 ）
并创建webjs3Test目录（命令mkdir webjs3Test以及命令cd webjs3Test）
在该目录下安装web3模块（命令npm --registry http://registry.npm.taobao.org install web3）
环境安装
执行命令npm init后一路回车
用vscode打开当前目录（命令code .）
其代买结构如下
代买结构
账户信息获取
没错，就是这么直接，我们现在就要获取账户信息了，创建index.js
创建index.js
并赋予其如下代码
var Web3 = require("web3")
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:7545"))
web3.eth.getAccounts()
.then(function (accounts) {
console.log("打印账户地址列表：");
console.log(accounts);
})
看代码中的打印行，我们就这么直接的获取Ganache中的账户并打印出来，是的，你没看错，就是这么直接，简单地一批
执行命令node index.js后，得到如下结果
账户信息
恭喜，成果获取到Ganache上的10个账户信息
合约部署
浏览器访问地址 http://remix.ethereum.org/ 并，定位到一个简单的例子上，如1_Storage.sol
1_Storage.sol
然后按照箭头3所示切入到编译功能区
编译区
点击Compile 1_Stroage.so按钮，编译成功后，会显示出编译详情等信息，此刻左侧的编译区按钮回有一个绿色的勾
点击编译详情后出现下面的界面
编译详情
滚动到WEB3DEPLOY，然后点击箭头出的复杂图标，将其拷贝到前面的代码后面
var Web3 = require('web3')
var web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:7545'))
web3.eth.getAccounts().then(function (account) {
console.log("打印账户地址列表：");
console.log(account);
})
var storageContract = new web3.eth.Contract([{"inputs":[],"name":"retrieve","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"num","type":"uint256"}],"name":"store","outputs":[],"stateMutability":"nonpayable","type":"function"}]);
var storage = storageContract.deploy({
data: '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',
arguments: [
]
}).send({
from: web3.eth.accounts[0],
gas: '4700000'
}, function (e, contract){
console.log(e, contract);
if (typeof contract.address !== 'undefined') {
console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash);
}
})
执行命令node index.js后，得到如下结果
运行出错
好吧，直接拷贝过来的代码看来不能正常运行，根据提示（红色标注），我们将14行的代码替换成账户地址A
var Web3 = require("web3")
var accound0Address = "0x6F5830e61F4ca16844261c118EE285CFa1006f5e"
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:7545"))
web3.eth.getAccounts()
.then(function (accounts) {
console.log("打印账户地址列表：");
console.log(accounts);
})
var storageContract = new web3.eth.Contract([{ "inputs": [], "name": "retrieve", "outputs": [{ "internalType": "uint256", "name": "", "type": "uint256" }], "stateMutability": "view", "type": "function" }, { "inputs": [{ "internalType": "uint256", "name": "num", "type": "uint256" }], "name": "store", "outputs": [], "stateMutability": "nonpayable", "type": "function" }]);
var storage = storageContract.deploy({
data: '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',
arguments: [
]
}).send({
from: accound0Address,
gas: '4700000'
}, function (e, contract) {
console.log(e, contract);
if (typeof contract.address !== 'undefined') {
console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash);
}
})
执行命令node index.js后，得到如下结果
部署成功
看上去是部署成功了，并打印出了交易的hash值，我们切换到Ganache里面去确认对比
Ganache部署详情1
Ganache部署详情2
没错，一样的，说明部署成功了，同时，在红色框的右下方，为我们新生成了一个合约地址，记为合约地址C
拿着合约地址无法无天
与之前获取合约的方式不同，我们需要根据合约地址C重新获取合约
var Web3 = require('web3')
var accound0Address = "0x6F5830e61F4ca16844261c118EE285CFa1006f5e"
var constractAddress = "0x3bCE924200544a39e085F6219e1750B00294e629"
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:7545"))
web3.eth.getAccounts()
.then(function (accounts) {
console.log("打印账户地址列表：");
console.log(accounts);
})
var abi = [{"inputs":[],"name":"retrieve","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"num","type":"uint256"}],"name":"store","outputs":[],"stateMutability":"nonpayable","type":"function"}];
var data = "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";
var myContract = new web3.eth.Contract(abi, constractAddress);
myContract.options.data = data;
myContract.methods.retrieve().call({ from: accound0Address }, function (error, result) {
console.log("结果：" + result);
});
我们把 abi以及data从之前的代码中提取出来，可以清晰的发现，新的合约获取，直接传入了constractAddress参数
之后，我们调用了合约中的retrieve方法（在合约部署小节中定义），并将结果打印
执行命令node index.js后，得到如下结果
方法调用结果1
可见，能够正常获取到 值
我们再调用合约中的store方法（在合约部署小节中定义），并将结果打印
var Web3 = require('web3')
var accound0Address = "0x6F5830e61F4ca16844261c118EE285CFa1006f5e"
var constractAddress = "0x3bCE924200544a39e085F6219e1750B00294e629"
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:7545"))
web3.eth.getAccounts()
.then(function (accounts) {
console.log("打印账户地址列表：");
console.log(accounts);
})
var abi = [{"inputs":[],"name":"retrieve","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"num","type":"uint256"}],"name":"store","outputs":[],"stateMutability":"nonpayable","type":"function"}];
var data = "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";
var myContract = new web3.eth.Contract(abi, constractAddress);
myContract.options.data = data;
myContract.methods.store(8).send({ from: accound0Address }, function (error, result) {
console.log("结果2s：" + result);
});
myContract.methods.retrieve().call({ from: accound0Address }, function (error, result) {
console.log("结果：" + result);
});
执行命令node index.js后，得到如下结果
方法调用结果2
结果还是0，这看起来不科学，应该是8呀。客官别急，我们执行的store和retrieve方法是异步的，结果不同步是应该的
再来一遍，执行命令node index.js后，得到如下结果
方法调用结果3
结果是8，那么就对了，我们再去核对一下交易hash
交易信息对比
果然能对上，又一次成功了
完！