以太坊day （4）
一、遇见的错误
1.1 Error: Invalid JSON RPC response:
- 原因:端口号填错
7545不是8545
web3.setProvider('HTTP://127.0.0.1:7545');
二、goland上进行合约的开发
2.1 需要的源
2.2 合约文件
pragma solidity ^0.4.26;
contract hello{
string public name = "jack";
function getName() public view returns (string){
return name;
}
function steNamt(string myname) public {
name = myname;
}
}
2.3 编译合约
let solc = require('solc')
let fs = require('fs')
let sourcecode = fs.readFileSync('./contracts/helloname.sol','utf-8')
//console.log(sourcecode.toString())
let output = solc.compile(sourcecode, 1)
//console.log(output['contracts'])
module.exports = output['contracts'][':hello']
2.4 部署合约
let {bytecode, interface} = require("./compile")
let Web3 = require("web3")
// console.log('bytecode:',bytecode)
// console.log('interface:',interface)
const account = "0xD5fFa32A808970FAb637AeE4ca70e00888B3e4D8"
let web3 = new Web3();
console.log("版本:",web3.version)
//1.设置网络
web3.setProvider('HTTP://127.0.0.1:7545');
//console.log(web3.providers)
//产看当前的currentProvider
//console.log(web3.currentProvider)
//2.拼接合约数据
let contract = new web3.eth.Contract(JSON.parse(interface))
//console.log("自己的contract:",contract)
web3.eth.defaultAccount = account;
//设置默认的账户
console.log(web3.eth.defaultAccount)
console.log(contract.defaultBlock)
// //3.拼接bytecode
contract.deploy({
data:bytecode,
arguments: ["success"]
})
.send({
from: account,
gas: 5721975,
gasPrice: '300000000000'
})
.then(function(newContractInstance){
//newContractInstance.options.address 得到的是新的合约的地址
console.log(newContractInstance.options.address) // instance with the new contract address
});
2.5 获取合约实例
//获取合约实例
let Web3 = require('web3')
let web3 = new Web3()
let {bytecode, interface} = require('./compile')
let contractAddress = require('./deploy')
console.log(interface)
console.log(contractAddress)
//根据api和address得到合约实例
let contracInstance = new web3.eth.Contract(JSON.parse(interface), contractAddress)
console.log(contracInstance)
2.6 与合约进行交互
//1.获取合约实例
let contractInstance = require('./instance')
const from = '0xC8147B0093339470dA5aaF4DFF643815c4adA893'
contractInstance.methods.getName().call().then(result =>{
//1.读取到合约的结果
console.log("得到的结果:",result)
//2.设置合约的变量值
contractInstance.methods.setName("currentJack").send({
from:from,
value:0}).then(res =>{
console.log(res)
//3.得到新的合约的值
contractInstance.methods.getName().call().then(res=>{
console.log("得到修改后的结果", res)
})
})
})
2.7 查看交易详细的应用
ganache
进去后点quick start
三、部署到真实的网络
3.1 所需的数据
- 助记词，花费谁的钱
- 服务商，帮助我们连接到真实的网络
infura - npm包，接受两个参数，然后帮我们链接到对应的网络
npm install truffle-hdwallet-provider
3.2 服务商,infura
- 记得选择ropsten
3.3 安装依赖
- npm install truffle-hdwallet-provider
3.4 设置provider
//1.合约的地址
let Web3 = require('web3')
let contractAddres = "合约的地址"
let {bytecode,interface} = require('./compile')
//console.log("得到的interface",interface)
let web3 = new Web3()
let THP = require('truffle-hdwallet-provider')
let terms = '账户的助记词'
//2.得到服务商网址
let netip = 'infura创建的项目的url'
let provider = new THP(terms, netip)
web3.setProvider(provider)
//console.log(web3.currentProvider)
//3.根据合约地址和api得到合约的实例
let contractInstance = new web3.eth.Contract(JSON.parse(interface),contractAddres)
//console.log("合约的实例",contractInstance)
module.exports = contractInstance