以太坊智能合约部署与交互

启动容器来执行geth命令

[email protected]:~# docker run -i blockchain101/ethereum-geth:1.6.5 geth attach http://45.32.252.88:8201
Welcome to the Geth JavaScript console!

instance: Geth/01/v1.6.5-stable/linux-amd64/go1.8
coinbase: 0x4c57e7e9c2f728046ddc6e96052056a241bdbd0a
at block: 6064 (Wed, 02 Aug 2017 01:13:50 UTC)
 datadir: /ethcluster/779977/data/01
 modules: admin:1.0 eth:1.0 net:1.0 rpc:1.0 web3:1.0

查看我们的账户和余额

eth.getBalance(eth.accounts[0])

11000000000000000000
eth.getBalance(eth.accounts[1])
0
eth.accounts[0]
"0x4c57e7e9c2f728046ddc6e96052056a241bdbd0a"
eth.accounts[1]
"0xe82e2f0a5abd8774767b9751659976f9c4f59181"

发起一笔交易

> 
eth.sendTransaction({from:eth.accounts[0],to:eth.accounts[1],value:web3.toWei(3,‘ether‘)}) "0x0075da712d26aea17d6647035107f509e13eaf3d113c1577db14d4cc4216caec"

查看交易细节

>  eth.getTransaction("0x0075da712d26aea17d6647035107f509e13eaf3d113c1577db14d4cc4216caec")

{
  blockHash: "0x3115703894dc6015c96ef4de3e5615f416498ca1f985902b38cd70e27dab8871",
  blockNumber: 1250,
  from: "0x4c57e7e9c2f728046ddc6e96052056a241bdbd0a",
  gas: 90000,
  gasPrice: 18000000000,
  hash: "0x0075da712d26aea17d6647035107f509e13eaf3d113c1577db14d4cc4216caec",
  input: "0x",
  nonce: 0,
  r: "0x2aef2c1fa03a0fa4172d21e3383d8c0431d45ec855b9d16efdd5eb2de90c414c",
  s: "0xc4d530fb7902bf509fe56bfbea4861bf6cc16791afc9c9103c1a18f77407d1f",
  to: "0xe82e2f0a5abd8774767b9751659976f9c4f59181",
  transactionIndex: 0,
  v: "0x17cdb6",
  value: 3000000000000000000
}
> eth.getBalance(eth.accounts[1])

3000000000000000000

验证用户0的余额

> eth.getBalance(eth.accounts[0])

7999622000000000000

编写一个简单的合约

contract Sample {
    uint public value;

          function Sample(uint v){
                    value=v;
          }

          function set(uint v){
                    value=v;
          }

          function get() constant returns (uint){
                    return value;
          }
}

在remix网页编译得到ABI接口和合约的二进制代码、

 abi=[{"constant":true,"inputs":[],"name":"value","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"v","type":"uint256"}],"name":"set","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"inputs":[{"name":"v","type":"uint256"}],"payable":false,"type":"constructor"}]

[{
    constant: true,
    inputs: [],
    name: "value",
    outputs: [{
        name: "",
        type: "uint256"
    }],
    payable: false,
    type: "function"
}, {
    constant: false,
    inputs: [{
        name: "v",
        type: "uint256"
    }],
    name: "set",
    outputs: [],
    payable: false,
    type: "function"
}, {
    constant: true,
    inputs: [],
    name: "get",
    outputs: [{
        name: "",
        type: "uint256"
    }],
    payable: false,
    type: "function"
}, {
    inputs: [{
        name: "v",
        type: "uint256"
    }],
    payable: false,
    type: "constructor"
}]

需要使用eth.contract来定义一个合约类

> sample=eth.contract(abi)

{
  abi: [{
      constant: true,
      inputs: [],
      name: "value",
      outputs: [{...}],
      payable: false,
      type: "function"
  }, {
      constant: false,
      inputs: [{...}],
      name: "set",
      outputs: [],
      payable: false,
      type: "function"
  }, {
      constant: true,
      inputs: [],
      name: "get",
      outputs: [{...}],
      payable: false,
      type: "function"
  }, {
      inputs: [{...}],
      payable: false,
      type: "constructor"
  }],
  eth: {
    accounts: ["0x4c57e7e9c2f728046ddc6e96052056a241bdbd0a", "0xe82e2f0a5abd8774767b9751659976f9c4f59181"],
    blockNumber: 6225,
    coinbase: "0x4c57e7e9c2f728046ddc6e96052056a241bdbd0a",
    compile: {
      lll: function(),
      serpent: function(),
      solidity: function()
    },
    defaultAccount: undefined,
    defaultBlock: "latest",
    gasPrice: 18000000000,
    hashrate: 0,
    mining: false,
    pendingTransactions: [],
    protocolVersion: "0x3f",
    syncing: false,
    call: function(),
    contract: function(abi),
    estimateGas: function(),
    filter: function(fil, callback),
    getAccounts: function(callback),
    getBalance: function(),
    getBlock: function(),
    getBlockNumber: function(callback),
    getBlockTransactionCount: function(),
    getBlockUncleCount: function(),
    getCode: function(),
    getCoinbase: function(callback),
    getCompilers: function(),
    getGasPrice: function(callback),
    getHashrate: function(callback),
    getMining: function(callback),
    getPendingTransactions: function(callback),
    getProtocolVersion: function(callback),
    getRawTransaction: function(),
    getRawTransactionFromBlock: function(),
    getStorageAt: function(),
    getSyncing: function(callback),
    getTransaction: function(),
    getTransactionCount: function(),
    getTransactionFromBlock: function(),
    getTransactionReceipt: function(),
    getUncle: function(),
    getWork: function(),
    iban: function(iban),
    icapNamereg: function(),
    isSyncing: function(callback),
    namereg: function(),
    resend: function(),
    sendIBANTransaction: function(),
    sendRawTransaction: function(),
    sendTransaction: function(),
    sign: function(),
    signTransaction: function(),
    submitTransaction: function(),
    submitWork: function()
  },
  at: function(address, callback),
  getData: function(),
  new: function()
}

合约的二进制代码赋值给SampleHEX方便使用

SampleHEX="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"

把合约代码部署上链

> thesample=sample.new(1,{from:eth.accounts[0],data:SampleHEX,gas:3000000})

{
  abi: [{
      constant: true,
      inputs: [],
      name: "value",
      outputs: [{...}],
      payable: false,
      type: "function"
  }, {
      constant: false,
      inputs: [{...}],
      name: "set",
      outputs: [],
      payable: false,
      type: "function"
  }, {
      constant: true,
      inputs: [],
      name: "get",
      outputs: [{...}],
      payable: false,
      type: "function"
  }, {
      inputs: [{...}],
      payable: false,
      type: "constructor"
  }],
  address: undefined,
  transactionHash: "0xee74bcb4461c9712ec9aca96a5a3a4c3c64be1213854d519fc8e5432b554f7a1"
}

查看交易细节

> samplerecpt=eth.getTransactionReceipt("0xee74bcb4461c9712ec9aca96a5a3a4c3c64be1213854d519fc8e5432b554f7a1")

{
  blockHash: "0xddba16545af882835fb9a69a0e5f3b9287c61664837d5ea0068b38575cb665c5",
  blockNumber: 6246,
  contractAddress: "0x7504fa9d64ab290844b82660d43b310f8fba0276",
  cumulativeGasUsed: 141836,
  from: "0x4c57e7e9c2f728046ddc6e96052056a241bdbd0a",
  gasUsed: 141836,
  logs: [],
  logsBloom: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  root: "0xd1093ecaca9cc0d10e82a533a15feccedf7ff5c79fb3ebd9366ec0b35dbef478",
  to: null,
  transactionHash: "0xee74bcb4461c9712ec9aca96a5a3a4c3c64be1213854d519fc8e5432b554f7a1",
  transactionIndex: 0
}

合约命名

> samplecontract=sample.at("0x7504fa9d64ab290844b82660d43b310f8fba0276")

{
  abi: [{
      constant: true,
      inputs: [],
      name: "value",
      outputs: [{...}],
      payable: false,
      type: "function"
  }, {
      constant: false,
      inputs: [{...}],
      name: "set",
      outputs: [],
      payable: false,
      type: "function"
  }, {
      constant: true,
      inputs: [],
      name: "get",
      outputs: [{...}],
      payable: false,
      type: "function"
  }, {
      inputs: [{...}],
      payable: false,
      type: "constructor"
  }],
  address: "0x7504fa9d64ab290844b82660d43b310f8fba0276",
  transactionHash: null,
  allEvents: function(),
  get: function(),
  set: function(),
  value: function()
}

合约查看功能函数get（）,然后调用set()函数，再get()查看时已经改变了

samplecontract.get.call()
1

> samplecontract.set.sendTransaction(9, {from:eth.accounts[0], gas:3000000})

"0x822ee6fb4caceb7e844c533f7f3bc57806f7cb3676fb3066eb848cca46b2f38a"

> samplecontract.get.call()

9

我们再打开一个终端，打开cluster1的peer02的控制台，直接at到上一个终端部署的智能合约地址并进行set操作

[email protected]:~/ethereum-docker/ethereum-docker/ethereum-testnet-docker/dockercomposefiles#  docker run -i blockchain101/ethereum-geth:1.6.5 geth attach http://45.32.252.88:9201
Welcome to the Geth JavaScript console!

>  abi=[{"constant":true,"inputs":[],"name":"value","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"v","type":"uint256"}],"name":"set","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"inputs":[{"name":"v","type":"uint256"}],"payable":false,"type":"constructor"}]

> sample=eth.contract(abi)

SampleHEX="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"

直接把合约地址赋值并进行set操作

samplecontract=sample.at("0x7504fa9d64ab290844b82660d43b310f8fba0276")

> samplecontract.get.call()

9

简单的方法来了。智能合约的部署需要编译，这里用在线编译： 
https://ethereum.github.io/browser-solidity/#version=soljson-v0.4.14+commit.c2215d46.js 
修改编译好的abi和对象名称：

这里在网上找了个代币的只能合约，可以进行充值、转账和查询，issue 函数可以向充值以太到合约账户，transfer 函数可以向其他账号发送token，getBalance 函数可以获取某个账号的token余额，代码如下：
pragma solidity ^0.4.2;
contract Token {
             address issuer;
             mapping (address => uint) balances;

             event Issue(address account, uint amount);
             event Transfer(address from, address to,uint amount);

             function Token() {
                 issuer = msg.sender;
             }

             function issue(address account, uintamount) {
                 if (msg.sender != issuer) throw;
                 balances[account] += amount;
             }

             function transfer(address to, uint amount){
                 if (balances[msg.sender] < amount)throw;

                 balances[msg.sender] -= amount;
                 balances[to] += amount;

                 Transfer(msg.sender, to, amount);
             }

             function getBalance(address account)constant returns (uint) {
                 return balances[account];
             }
         }
修改编译好的gas和对象名称：
varbrowser_untitled_sol_tokenContract =web3.eth.contract([{"constant":false,"inputs":[{"name":"account","type":"address"},{"name":"amount","type":"uint256"}],"name":"issue","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"amount","type":"uint256"}],"name":"transfer","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"account","type":"address"}],"name":"getBalance","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"inputs":[],"payable":false,"type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"account","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"Issue","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"from","type":"address"},{"indexed":false,"name":"to","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"Transfer","type":"event"}]);
var token =browser_untitled_sol_tokenContract.new(
   {
     from: web3.eth.accounts[0],
     data:‘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‘,
     gas: ‘4300000‘
   }, function (e, contract){
    console.log(e, contract);
    if (typeof contract.address !==‘undefined‘) {
         console.log(‘Contract mined! address:‘ + contract.address + ‘ transactionHash: ‘ + contract.transactionHash);
    }
 })

此时输入合约部署的实例a_demotypes, 可以看到a_demotypes的详情。

控制台调用

> a_demotypes
{
  abi: [{
      constant: false,
      inputs: [{...}],
      name: "f",
      outputs: [{...}],
      payable: false,
      type: "function"
  }],
  address: "0x54ed7a5f5a63ddada3bfe83b3e632adabaa5fc2f",
  transactionHash: "0x69cde62bcd6458e14f40497f4840f422911d63f5dea2b3a9833e6810db64a1c9",
  allEvents: function(),
  f: function()
}

这里重点就是address表示的是合约的地址，你会发现这个和账号的信息结果一样，其实你也可以把这个合约地址看做是一个账号地址，后面我们外部调用到的就是这个合约地址。

充值
token.issue.sendTransaction(eth.accounts[0],100, {from: eth.accounts[0]});

发送 token
token.transfer(eth.accounts[1], 30, {from:eth.accounts[0]})

查看余额
token.getBalance()
控制台调用就不多说，和Java对象调用一样，直接调用即可

外部接口与智能合约交互 
以太坊对外提供的有很多接口JSON RPC接口，web3接口，这里我们用JSON RPC接口。 
相关API: https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sendrawtransaction 
合约交互的原理 
合约的交互都是一次交易，而我们要做的就是把要调用的方法和参数按照api规定的以参数的形式向区块请求一次交易，ethereum接收到我们的请求后通过解析传递的参数来执行相关的合约代码。 
RPC接口给我们提供了俩个方法：eth_sendTransaction和eth_call。

eth_sendTransaction
Createsnew message call transaction or a contract creation, if the data field containscode.
Parameters

Object - The transaction object
from: DATA, 20 Bytes - The address the transaction is send from.
to: DATA, 20 Bytes - (optional when creating new contract) The address the transaction is directed to.
gas: QUANTITY - (optional, default: 90000) Integer of the gas provided for the transaction execution. It will return unused gas.
gasPrice: QUANTITY - (optional, default: To-Be-Determined) Integer of the gasPrice used for each paid gas
value: QUANTITY - (optional) Integer of the value send with this transaction
data: DATA - The compiled code of a contract OR the hash of the invoked method signature and encoded parameters. For details see Ethereum Contract ABI
nonce: QUANTITY - (optional) Integer of a nonce. This allows to overwrite your own pending transactions that use the same nonce.

可以看到，如果我们创建的为合约时，我们只需要from,to(文档上写的是可选的，但是实际操作中没有to为null的话合约不能正常执行，建议还是加上，这个值就是前面我们部署合约后生成的合约address),data。Data的属性的值具体可以看Contract ABI。这里大概说下： 
Data的值相对来说不是固定的，具体怎么生成与合约的参数类型，参数数量都有关联。这里我们以部署的token合约的三个方法为例：

充值issue (address account, uint amount) 
这个方法有俩个参数，address充值账号，uint充值数量。 
根据Contract ABI，data值应该为方法名的sha3的前8个字节+参数的64字节，不够前面补充为0。 
这里方法名并不是issue (address account, uint amount)而是issue(address,uint256)的sha3值。

web3.sha3("issue(address,uint256)")
"0x867904b44b606800f6f10498e11292d04ea19bfc7fe4bc0f1695aa516381f73d"

我们往第一个账号充值10，这里的数据不是以太币，而是我们自己创建的代币。

 eth.accounts[0]
"0x0cc9684af605bae10de801218321c1336bb62946"

将10转换为16进制为

000000000000000000000000000000000000000000000000000000000000000a

那么data的数据为：

0x867904b4000000000000000000000000fdf57e81872562a6112656f961944ce821fdf7eb000000000000000000000000000000000000000000000000000000000000000a

那么最后我们调用eth_sendTransaction方法传递参数JSON对象为：

{
    from:0xfdf57e81872562a6112656f961944ce821fdf7eb,
to:0x7fe133950fc010ce41322d88f64f1918b9abb3a3,
data: 0x867904b4000000000000000000000000fdf57e81872562a6112656f961944ce821fdf7eb000000000000000000000000000000000000000000000000000000000000000a
}

返回：此交易的hash值,此时该交易还没有执行，只是创建，还需要矿工通过挖矿才能完成。 
调用接口方法：

JsonRpcHttpClient client = newJsonRpcHttpClient(new URL(“http://127.0.0.1:8545”));
Object result = client.invoke(methodName,params, Object.class);

通过控制台查看第一个账号已有代币：

token.getbalance(eth.accounts[0])

执行调用接口代码。返回交易hash值：

0x2013764d1c3fea680f9015353497aa5f9f8d61580a3bd0524b3613b34329c095

此时控制台输入： 

交易和充值一样，需要注意的是代币转出账号为from属性的值，代币转入账号为data属性里的值，to对应的是合约地址。 
eth_call

Executes anew message call immediately without creating a transaction on the block chain.
Parameters

Object - The transaction call object
from: DATA, 20 Bytes - (optional) The address the transaction is sent from.
to: DATA, 20 Bytes - The address the transaction is directed to.
gas: QUANTITY - (optional) Integer of the gas provided for the transaction execution. eth_call consumes zero gas, but this parameter may be needed by some executions.
gasPrice: QUANTITY - (optional) Integer of the gasPrice used for each paid gas
value: QUANTITY - (optional) Integer of the value send with this transaction
data: DATA - (optional) Hash of the method signature and encoded parameters. For details seeEthereum Contract ABI
QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending", see the default block parameter

这个方法返回一条信息给我们，相当于数据库的查询功能，参数也是三个，from,to,data，数据格式都是一样的。 
查询getBalance(address account) 
查询方法hash码：

 web3.sha3("getBalance(address)")
"0xf8b2cb4f3943230388faeee074f1503714bff212640051caba01411868d14ae3"

查询我们上一步充值的账号，那么传递的参数data为：

0xf8b2cb4f000000000000000000000000fdf57e81872562a6112656f961944ce821fdf7eb

eth_call方法最后参数为：

{
       from: 0xfdf57e81872562a6112656f961944ce821fdf7eb,
to:0x7fe133950fc010ce41322d88f64f1918b9abb3a3,
data:0xf8b2cb4f000000000000000000000000fdf57e81872562a6112656f961944ce821fdf7eb
}

注意，这个方法需要俩参数，处理一个JSONobject外，还有一个字符串参数，这俩可以为“”或者”latest”, “earliest” or “pending” 
调用接口返回一个16进制字符串： 
0x0000000000000000000000000000000000000000000000000000000000000071就是该账号的代币数量，转换为十进制为：113，与控制查询一致。

这就是一个智能合约的交互过程。是不是很简单啊。

原文地址：https://www.cnblogs.com/helloworld2018/p/8977026.html

时间： 2024-08-29 15:54:41

以太坊智能合约部署与交互的相关文章

web3j开发以太坊智能合约快速入门(特别适合java和android开发者)

web3j简介 web3j是一个轻量级.高度模块化.响应式.类型安全的Java和Android类库提供丰富API,用于处理以太坊智能合约及与以太坊网络上的客户端(节点)进行集成. 可以通过它进行以太坊区块链的开发,而无需为你的应用平台编写集成代码. 可以快速启动dmeo示例 想要快速启动的话,有一个Web3j demo示例项目可用,演示了通过Web3j开发以太坊的许多核心特征,其中包括: 连接到以太网网络上的节点 加载一个以太坊钱包文件 将以太币从一个地址发送到另一个地址 向网络部署智能合约 从

2018年以太坊智能合约开发语言Solidity最佳IDEs

Solidity是一种以智能合约为导向的编程语言.这是一种只有四年的年轻语言,旨在帮助开发基于以太坊数字货币的智能合约. 理解它官方文档应该是学习Solidity的最佳来源:solidity.readthedocs.io 想在以太坊的网络上建立自己的加密货币吗?想拥有自己的初始代码产品吗?以下是您今天可以使用的最佳Solidity IDE. Remix IDE Remix IDE是基于浏览器的,并且集成了编译器.没有服务器端组件. 官网: https://remix.ethereum.orggi

深入以太坊智能合约 ABI

开发 DApp 时要调用在区块链上的以太坊智能合约,就需要智能合约的 ABI.本文希望更多了解 ABI,如为什么需要 ABI?如何解读 Ethereum 的智能合约 ABI?以及如何取得合约的 ABI? 数字猫合约 ABI ABI(Application Binary Interface) 如果理解 API 就很容易了解 ABI.简单来说,API 是程序与程序间互动的接口.这个接口包含程序提供外界存取所需的 functions.variables 等.ABI 也是程序间互动的接口,但程序是被编译

以太坊智能合约入门项目-众筹项目

一.智能合约 智能合约(英语:Smart Contract)是一种旨在以信息化方式传播.验证或执行合同的计算机协议.智能合约允许在没有第三方的情况下进行可信交易.这些交易可追踪且不可逆转.智能合约概念于1994年由Nick Szabo首次提出. 以上解释来自于维基百科 由于缺少可信的执行环境,智能合约并没有被应用到实际产业中,自比特币诞生后,人们认识到比特币的底层技术区块链天生可以为智能合约提供可信的执行环境,以太坊首先看到了区块链和智能合约的契合,发布了白皮书<以太坊:下一代智能合约和去中心化

rpc接口调用以太坊智能合约

rpc接口调用以太坊智能合约 传送门: 柏链项目学院 ??在以太坊摸爬滚打有些日子了,也遇到了各种各样的问题.这几天主要研究了一下如何通过rpc接口编译.部署和调用合约.也遇到了一些困难和问题,下面将向大家分享. rpc接口调用智能合约 先来编写一个简单的智能合约 contract Multiply7 { event Print(uint); function multiply(uint input) returns (uint) { Print(input * 7); return input

以太坊智能合约及应用开发简介

在这个入门教程中我们将建立以太坊应用开发环境并学习编写一个投票智能合约. 在这个教程中,让我们构建一个简单的"Hello World!" 应用程序, 这是一个投票应用程序. 该应用程序非常简单,它所做的只是初始化一组候选人,让任何人投票给候选人,并显示每个候选人收到的总票数. 我有意避免使用任何DAPP框架构建这个应用程序,因为框架抽象掉很多细节,你不了解系统的内部.此外,当你使用框架时,将对框架所做的繁重工作有更多的体会! 1. 设置开发环境 我们使用一个模拟的内存区块链(ganac

以太坊智能合约项目-Token合约开发与部署

修订日期 姓名 邮箱 2019-09-05 brucefeng [email protected] 一. 钱包环境安装 以太坊钱包顾名思义,就是管理以太坊地址,存储以太坊Token的工具,再简单点说,任何区块链网络都需要我们有自己的账户,管理账户的软件可称之为钱包,无论是炒币的还是研究以太坊开发的,钱包都是必不可少的. 1.钱包分类 1.1 Mist 说到以太坊钱包,第一个要说的当然就是Ethereum官方钱包+浏览器 Mist.Mist是一个全节点钱包(全节点钱包通俗的来说就是同步了全部的以太

如何用python和flask以太坊智能合约开发

将数据存储在数据库中是任何软件应用程序不可或缺的一部分.无论如何控制该数据库都有一个该数据的主控.区块链技术将数据存储到区块链网络内的区块中.因此,只要某个节点与网络同步,它们就会获得区块中数据的副本.因此,该技术中没有特定的数据主控. 在本教程中,我们将编写一份智能合约(我将进一步解释),以便在区块链上保留用户数据.我们将使用python web3(web3的python库)来开发和部署智能合约.一旦我们在区块链上部署了智能合约.我们将使用flask API与智能合约进行交互以存储一些数据/信

通过一个案例精通以太坊智能合约和Solidity

作者介绍 Silver CEO 星际区块链信息发展有限公司 项目组件 ??这个项目是一个构建在以太坊上的游戏,感谢这个团队给我们提供的案例:https://cryptozombies.io ??从功能的角度看,有如下脚本: zombiefactory.sol:定义zombie和生成zombie. zombiefeeding.sol:定义小猫接口,给zombie吃小猫. zombieattack.sol:zombie打架的功能. erc721.sol:ERC721代币的接口. ownable.so