The web3tutorial from 1538402109

简介

web3.js 是一个通过RPC 调用和本地以太坊节点进行通信的js库。web3.js可以与任何暴露了RPC接口的以太坊节点连接。 web3中提供了eth对象 - web3.eth来与以太坊区块链进行交互。

安装和和获取web3对象

安装 npm: npm install web3 bower: bower install web3 metor: meteor add ethereum:web3 vanilla: dist./web3.min.js 获得web3实例

if (typeof web3 !== 'undefined') {
  web3 = new Web3(web3.currentProvider);
} else {
  // set the provider you want from Web3.providers
  web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}

使用实例

一、账户操作：

创建新账户

web3.eth.accounts.create();
> {
    address: "0xb8CE9ab6943e0eCED004cDe8e3bBed6568B2Fa01",
    privateKey: "0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709",
    signTransaction: function(tx){...},
    sign: function(data){...},
    encrypt: function(password){...}
}

web3.eth.accounts.create('2435@#@#@±±±±!!!!678543213456764321§34567543213456785432134567');
> {
    address: "0xF2CD2AA0c7926743B1D4310b2BC984a0a453c3d4",
    privateKey: "0xd7325de5c2c1cf0009fac77d3d04a9c004b038883446b065871bc3e831dcd098",
    signTransaction: function(tx){...},
    sign: function(data){...},
    encrypt: function(password){...}
}

web3.eth.accounts.create(web3.utils.randomHex(32));
> {
    address: "0xe78150FaCD36E8EB00291e251424a0515AA1FF05",
    privateKey: "0xcc505ee6067fba3f6fc2050643379e190e087aeffe5d958ab9f2f3ed3800fa4e",
    signTransaction: function(tx){...},
    sign: function(data){...},
    encrypt: function(password){...}
}

使用私钥创建账户

web3.eth.accounts.privateKeyToAccount(privateKey);

web3.eth.accounts.privateKeyToAccount('0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709');
> {
    address: '0xb8CE9ab6943e0eCED004cDe8e3bBed6568B2Fa01',
    privateKey: '0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709',
    signTransaction: function(tx){...},
    sign: function(data){...},
    encrypt: function(password){...}
}

web3.eth.accounts.privateKeyToAccount('0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709');
> {
    address: '0xb8CE9ab6943e0eCED004cDe8e3bBed6568B2Fa01',
    privateKey: '0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709',
    signTransaction: function(tx){...},
    sign: function(data){...},
    encrypt: function(password){...}
}

使用私钥签名一个交易

web3.eth.accounts.signTransaction(tx, privateKey [, callback]);

web3.eth.accounts.signTransaction({
    to: '0xF0109fC8DF283027b6285cc889F5aA624EaC1F55',
    value: '1000000000',
    gas: 2000000
}, '0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318')
.then(console.log);
> {
    messageHash: '0x88cfbd7e51c7a40540b233cf68b62ad1df3e92462f1c6018d6d67eae0f3b08f5',
    v: '0x25',
    r: '0xc9cf86333bcb065d140032ecaab5d9281bde80f21b9687b3e94161de42d51895',
    s: '0x727a108a0b8d101465414033c3f705a9c7b826e596766046ee1183dbc8aeaa68',
    rawTransaction: '0xf869808504e3b29200831e848094f0109fc8df283027b6285cc889f5aa624eac1f55843b9aca008025a0c9cf86333bcb065d140032ecaab5d9281bde80f21b9687b3e94161de42d51895a0727a108a0b8d101465414033c3f705a9c7b826e596766046ee1183dbc8aeaa68'
}

web3.eth.accounts.signTransaction({
    to: '0xF0109fC8DF283027b6285cc889F5aA624EaC1F55',
    value: '1000000000',
    gas: 2000000,
    gasPrice: '234567897654321',
    nonce: 0,
    chainId: 1
}, '0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318')
.then(console.log);
> {
    messageHash: '0x6893a6ee8df79b0f5d64a180cd1ef35d030f3e296a5361cf04d02ce720d32ec5',
    r: '0x9ebb6ca057a0535d6186462bc0b465b561c94a295bdb0621fc19208ab149a9c',
    s: '0x440ffd775ce91a833ab410777204d5341a6f9fa91216a6f3ee2c051fea6a0428',
    v: '0x25',
    rawTransaction: '0xf86a8086d55698372431831e848094f0109fc8df283027b6285cc889f5aa624eac1f55843b9aca008025a009ebb6ca057a0535d6186462bc0b465b561c94a295bdb0621fc19208ab149a9ca0440ffd775ce91a833ab410777204d5341a6f9fa91216a6f3ee2c051fea6a0428'
}

哈希一个消息

web3.eth.accounts.hashMessage(message);

web3.eth.accounts.hashMessage("Hello World")
> "0xa1de988600a42c4b4ab089b619297c17d53cffae5d5120d82d8a92d0bb3b78f2"

// the below results in the same hash
web3.eth.accounts.hashMessage(web3.utils.utf8ToHex("Hello World"))
> "0xa1de988600a42c4b4ab089b619297c17d53cffae5d5120d82d8a92d0bb3b78f2"

sign 给任意一个内容使用私钥签名

web3.eth.accounts.sign(data, privateKey);

web3.eth.accounts.sign('Some data', '0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318');
> {
    message: 'Some data',
    messageHash: '0x1da44b586eb0729ff70a73c326926f6ed5a25f5b056e7f47fbc6e58d86871655',
    v: '0x1c',
    r: '0xb91467e570a6466aa9e9876cbcd013baba02900b8979d43fe208a4a4f339f5fd',
    s: '0x6007e74cd82e037b800186422fc2da167c747ef045e5d18a5f5d4300f8e1a029',
    signature: '0xb91467e570a6466aa9e9876cbcd013baba02900b8979d43fe208a4a4f339f5fd6007e74cd82e037b800186422fc2da167c747ef045e5d18a5f5d4300f8e1a0291c'
}

encrypt 加密 keystore

传入私钥和密码

web3.eth.accounts.encrypt('0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318', 'test!')
> {
    version: 3,
    id: '04e9bcbb-96fa-497b-94d1-14df4cd20af6',
    address: '2c7536e3605d9c16a7a3d7b1898e529396a65c23',
    crypto: {
        ciphertext: 'a1c25da3ecde4e6a24f3697251dd15d6208520efc84ad97397e906e6df24d251',
        cipherparams: { iv: '2885df2b63f7ef247d753c82fa20038a' },
        cipher: 'aes-128-ctr',
        kdf: 'scrypt',
        kdfparams: {
            dklen: 32,
            salt: '4531b3c174cc3ff32a6a7a85d6761b410db674807b2d216d022318ceee50be10',
            n: 262144,
            r: 8,
            p: 1
        },
        mac: 'b8b010fff37f9ae5559a352a185e86f9b9c1d7f7a9f1bd4e82a5dd35468fc7f6'
    }
}

解密

web3.eth.accounts.decrypt({
    version: 3,
    id: '04e9bcbb-96fa-497b-94d1-14df4cd20af6',
    address: '2c7536e3605d9c16a7a3d7b1898e529396a65c23',
    crypto: {
        ciphertext: 'a1c25da3ecde4e6a24f3697251dd15d6208520efc84ad97397e906e6df24d251',
        cipherparams: { iv: '2885df2b63f7ef247d753c82fa20038a' },
        cipher: 'aes-128-ctr',
        kdf: 'scrypt',
        kdfparams: {
            dklen: 32,
            salt: '4531b3c174cc3ff32a6a7a85d6761b410db674807b2d216d022318ceee50be10',
            n: 262144,
            r: 8,
            p: 1
        },
        mac: 'b8b010fff37f9ae5559a352a185e86f9b9c1d7f7a9f1bd4e82a5dd35468fc7f6'
    }
}, 'test!');
> {
    address: "0x2c7536E3605D9C16a7a3D7b1898e529396a65c23",
    privateKey: "0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318",
    signTransaction: function(tx){...},
    sign: function(data){...},
    encrypt: function(password){...}
}

钱包

获得钱包

eb3.eth.accounts.wallet;

web3.eth.accounts.wallet;
> Wallet {
    0: {...}, // account by index
    "0xF0109fC8DF283027b6285cc889F5aA624EaC1F55": {...},  // same account by address
    "0xf0109fc8df283027b6285cc889f5aa624eac1f55": {...},  // same account by address lowercase
    1: {...},
    "0xD0122fC8DF283027b6285cc889F5aA624EaC1d23": {...},
    "0xd0122fc8df283027b6285cc889f5aa624eac1d23": {...},

    add: function(){},
    remove: function(){},
    save: function(){},
    load: function(){},
    clear: function(){},

    length: 2,
}

使用web3.eth.personal 新建账户

web3.eth.personal.newAccount(password, [callback])

web3.eth.personal.newAccount('!@superpassword')
.then(console.log);
> '0x1234567891011121314151617181920212223456'

获得账户余额

web3.eth.getBalance('0xe70c4835b29e2fd35bd3f60c0a76413f70f17115').then(function(balance){
     console.log('balance:',balance)
     balance = new BigNumber(balance)
     console.log('balance:',balance)
})

这里使用了BigNumber.js 处理余额显示，参考我另一片博文。

utils工具函数

#####web3.utils.toHex 将任何值转为HEX 16进制 String|Number|Object|Array|BigNumber - 需要转化为HEX的值。如果是一个对象或数组类型，将会先用JSON.stringify1进行转换成字符串。如果传入的是BigNumber2，则将得到对应的Number的HEX

var str = "abcABC";
var obj = {abc: 'ABC'};
var bignumber = new BigNumber('12345678901234567890');

var hstr = web3.utils.toHex(str);
var hobj = web3.utils.toHex(obj);
var hbg = web3.utils.toHex(bignumber);

console.log("Hex of Sring:" + hstr);
console.log("Hex of Object:" + hobj);
console.log("Hex of BigNumber:" + hbg);

web3.utils.isHex(hex) 判断输入是不是16进制

web3.utils.isHex('0xc1912');

判断输入是不是一个地址

web3.utils.isAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d');

把金额单位换成wei

web3.utils.toWei(number [, unit])

web3.utils.toWei('1', 'ether');
> "1000000000000000000"

web3.utils.toWei('1', 'finney');
> "1000000000000000"

web3.utils.toWei('1', 'szabo');
> "1000000000000"

web3.utils.toWei('1', 'shannon');
/> "1000000000"

把单位为wei的以太币换成 ether

web3.utils.fromWei(number [, unit])

web3.utils.fromWei('1', 'ether');
> "0.000000000000000001"

web3.utils.fromWei('1', 'finney');
> "0.000000000000001"

web3.utils.fromWei('1', 'szabo');
> "0.000000000001"

web3.utils.fromWei('1', 'shannon');
> "0.000000001"

判断给定的数据是否是 BigNumber

web3.utils.isBigNumber(bignumber)

var number = new BigNumber(10);
web3.utils.isBigNumber(number);

sha3算法

// web3.utils.sha3(string) // web3.utils.keccak256(string) // ALIAS

web3.utils.sha3('234'); // taken as string
> "0xc1912fee45d61c87cc5ea59dae311904cd86b84fee17cc96966216f811ce6a79"

web3.utils.sha3(new BN('234'));
> "0xbc36789e7a1e281436464229828f817d6612f7b477d66591ff96a9e064bcc98a"

web3.utils.sha3(234);
> null // can't calculate the has of a number

web3.utils.sha3(0xea); // same as above, just the HEX representation of the number
> null

web3.utils.sha3('0xea'); // will be converted to a byte array first, and then hashed
> "0x2f20677459120677484f7104c76deb6846a2c071f9b3152c103bb12cd54d1a4a"

在github上获得代码

1538402109 / web3tutorial Goto Github PK

web3tutorial's Introduction

简介