以太坊开发：web3js（四）用web3js编写以太坊脚本

1. 基本方式转账：转以太币

var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

var arguments = process.argv.splice(2);

if(!arguments || arguments.length != 2) {
     
        console.log("Parameter error!");
        return;
}
var _from = web3.eth.accounts[0];
var _to = "0x47fb1c31b3d1a2814b1f37ecb0655ba51fc34c93";

var _value = 500000000;

web3.eth.sendTransaction({
     from:_from, to: _to, value: _value}, (err, res)=>{
     
        if(err)
        console.log("Error:", err);
        else
        console.log("Result:", res)
});

编译合约：

gexiao@gexiaovm:~/geth/0403/web3_test/contract$ cd ..
gexiao@gexiaovm:~/geth/0403/web3_test$ ls
contract  node_modules  package.json  package-lock.json
gexiao@gexiaovm:~/geth/0403/web3_test$ vi transfer_script.js
gexiao@gexiaovm:~/geth/0403/web3_test$ node transfer_script.js

2. 转账自己编写的代币

var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

var _from = web3.eth.accounts[0];
var _to = web3.eth.accounts[1];
var amount = 50000;

var abi = [{
     "constant":true,"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{
     "anonymous":false,"inputs":[{
     "indexed":false,"internalType":"address","name":"from","type":"address"},{
     "indexed":false,"internalType":"address","name":"to","type":"address"},{
     "indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Sent","type":"event"},{
     "inputs":[{
     "internalType":"address","name":"","type":"address"}],"name":"balances","outputs":[{
     "internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"mint","outputs":[],"stateMutability":"nonpayable","type":"function"},{
     "inputs":[],"name":"minter","outputs":[{
     "internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"send","outputs":[],"stateMutability":"nonpayable","type":"function"}]
var CoinContract = web3.eth.contract(abi);
var contractAddress = "0x47Fb1C31B3D1A2814B1f37EcB0655BA51Fc34C93";
var contractInstance = CoinContract.at(contractAddress);

contractInstance.send(_to, amount, {
     from:_from}, (err, res)=>{
     
if(err)
console.log("Error:", err);
else
console.log("Result:", res);
});

3. 脚本内直接解锁转账

var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

var arguments = process.argv.slice(2);
if(!arguments || arguments.length!=2) {
     
console.log("Parameter length must be 2");
return;
}

var _from = web3.eth.accounts[0];
var _to = web3.eth.accounts[1];
var amount = 50000;

var abi = [{
     "constant":true,"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{
     "anonymous":false,"inputs":[{
     "indexed":false,"internalType":"address","name":"from","type":"address"},{
     "indexed":false,"internalType":"address","name":"to","type":"address"},{
     "indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Sent","type":"event"},{
     "inputs":[{
     "internalType":"address","name":"","type":"address"}],"name":"balances","outputs":[{
     "internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"mint","outputs":[],"stateMutability":"nonpayable","type":"function"},{
     "inputs":[],"name":"minter","outputs":[{
     "internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"send","outputs":[],"stateMutability":"nonpayable","type":"function"}]
var CoinContract = web3.eth.contract(abi);
var contractAddress = "0x47Fb1C31B3D1A2814B1f37EcB0655BA51Fc34C93";
var contractInstance = CoinContract.at(contractAddress);

web3.personal.unlockAccount(_from, '自定义的密码', (err, res)=>{
     
if(err)
console.log("Error:", err);
else{
     
contractInstance.send(_to, amount, {
     from:_from}, (err, res)=>{
     
if(err)
console.log("Error:", err);
else
console.log("Result:", res);
});
}
});

4. 查询账户信息

var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

var arguments = process.argv.slice(2);

if(!arguments || arguments.length!=1) {
     
console.log("Parameter length must be 1");
return;
}

var _addr = arguments[0];

var abi = [{
     "constant":true,"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{
     "anonymous":false,"inputs":[{
     "indexed":false,"internalType":"address","name":"from","type":"address"},{
     "indexed":false,"internalType":"address","name":"to","type":"address"},{
     "indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Sent","type":"event"},{
     "inputs":[{
     "internalType":"address","name":"","type":"address"}],"name":"balances","outputs":[{
     "internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"mint","outputs":[],"stateMutability":"nonpayable","type":"function"},{
     "inputs":[],"name":"minter","outputs":[{
     "internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"send","outputs":[],"stateMutability":"nonpayable","type":"function"}]
var CoinContract = web3.eth.contract(abi);
var contractAddress = "0x47Fb1C31B3D1A2814B1f37EcB0655BA51Fc34C93";
var contractInstance = CoinContract.at(contractAddress);

contractInstance.balances(_addr, (err, res)=>{
     
	if(err)
		console.log("Error:", err);
	else
		console.log("Result:", res);
}) ;

5. 事件监听

var Web3 = require('web3');
var web3 = new Web3(new web3.providers.HttpProvider("http://localhost:8545"));

var abi = [{
     "constant":true,"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{
     "anonymous":false,"inputs":[{
     "indexed":false,"internalType":"address","name":"from","type":"address"},{
     "indexed":false,"internalType":"address","name":"to","type":"address"},{
     "indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Sent","type":"event"},{
     "inputs":[{
     "internalType":"address","name":"","type":"address"}],"name":"balances","outputs":[{
     "internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"mint","outputs":[],"stateMutability":"nonpayable","type":"function"},{
     "inputs":[],"name":"minter","outputs":[{
     "internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{
     "inputs":[{
     "internalType":"address","name":"receiver","type":"address"},{
     "internalType":"uint256","name":"amount","type":"uint256"}],"name":"send","outputs":[],"stateMutability":"nonpayable","type":"function"}];
var contractAddr = "0x47Fb1C31B3D1A2814B1f37EcB0655BA51Fc34C93";
var CoinContract = web3.eth.contract(abi);
var contractInstance = CoinContract.at(contractAddr);

contractInstance.Sent("latest", (err, res)=>{
     
	if(err)
		console.log("Error:", err);
	else
		console.log("Sent Event occurs:", res);
});