Nethereum.Unity开发教程

Nethereum.Unity 库是一个特定于 Nethereum 的 Unity 库和 API，它支持 UnityWebRequest 使用 RPC over Http 与 Ethereum 交互。Nethereum.Unity 库是唯一支持在 Unity 中使用协程时使用 IEnumerator 和 yield 的库。

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1、Nethereum.Unity简介

如果想在 net461 / netstandard 中使用 async / await 和 Tasks，只要你的环境不需要使用 UnityWebRequest 而不是 HttpRequest，也可以使用与“vanilla” Nethereum 相同的方式。 （Webgl 需要使用 UnityWebRequest）

Nethereum 还为 net351 和 net461 框架构建提供了 AoT 库。 所有“dll”都可以从 Nethereum github 下载。

flappy eth 是 Unity3d 的“flappy”示例，使用 Nethereum 作为 webgl dapp 游戏转换为 与 Ethereum、Infura 和 Metamask 交互。主要集成组件的源代码可以在这里找到, 你也可以在这里尝试游戏。

2、Unity3dSimpleSample示例简介

Unity3dSimpleSample是使用 Net472（现在从 Net461 升级）进行 Unity3d 开发的简单示例，使用的 Unity 版本是 2020.3.15f LTS。 示例中包含资产文件夹中的所有 DLL，你可能不需要其中一些代码，直接删除它们（如 Besu、Geth、HdWallet、NBitcoin 等）就可以了，具体 取决于你的需要。

示例代码演示了如何使用Nethereum.Unity实现以下功能：

• 在异步和协程中使用 Unity.UI 将当前 BlockNumber 输出到日志
• 使用 Unity.UI 和协程进行以太传输
• ETH转账时使用 1559 Suggestion 策略或 Legacy 模式
• 智能合约部署（ERC20）、交易（Transfer）和查询（Balance）

• WebGL 仅支持协程 UnityWebRequest。如果构建 WebGL版本发生问题，请取消选中 Development Build。
• 为了支持 WebGL 和 AOT，此示例使用 Net472AOT dll 和自定义 Json.Net Unity
• 请记住删除 Nethereum 发布包的 System.HttpClient 和 UnityEngine

下面是桌面版的截图：

下面是WebGL版的截图：

要运行本地区块链，可以使用预配置的测试链。

3、异步查询区块号 — 非协程方式

下面的代码展示了如何用Nethereum.Unity异步查询区块号：

using System;
using System.Collections;
using System.Collections.Generic;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using Nethereum.ABI.FunctionEncoding.Attributes;
using UnityEngine;
using UnityEngine.UI;
using Nethereum.Contracts;
using Nethereum.Web3;


public class GetLatestBlockVanillaNethereum : MonoBehaviour {

private static bool TrustCertificate(object sender, X509Certificate x509Certificate, X509Chain x509Chain, SslPolicyErrors sslPolicyErrors)
    {
        // all certificates are accepted
        return true;
    }

public string Url = "https://mainnet.infura.io";

public InputField ResultBlockNumber;
    public InputField InputUrl;

// Use this for initialization
    void Start()
    {
        InputUrl.text = Url;
    }

public async void GetBlockNumber()
	{
        Url = InputUrl.text;
        //This is to workaround issue with certificates https://forum.unity.com/threads/how-to-allow-self-signed-certificate.522183/
        //Uncomment if needed
        // ServicePointManager.ServerCertificateValidationCallback = TrustCertificate;
        var web3 = new Web3(Url);

var blockNumber = await web3.Eth.Blocks.GetBlockNumber.SendRequestAsync();
        ResultBlockNumber.text = blockNumber.Value.ToString();
    }
}

4、异步查询区块号 — 协程方式

下面的代码展示了如何用Nethereum.Unity以协程方式异步查询区块号：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using Nethereum.JsonRpc.UnityClient;
using Nethereum.RPC.Eth.DTOs;
using Nethereum.Util;

public class GetLatestBlockCoroutine : MonoBehaviour
{
    public string Url = "https://mainnet.infura.io";

public InputField ResultBlockNumber;
    public InputField InputUrl;

// Use this for initialization
    void Start()
    {
        InputUrl.text = Url;
    }

public void GetBlockNumberRequest()
    {
        StartCoroutine(GetBlockNumber());
    }

public IEnumerator GetBlockNumber()
    {
        Url = InputUrl.text;

var blockNumberRequest = new EthBlockNumberUnityRequest(Url);

yield return blockNumberRequest.SendRequest();

ResultBlockNumber.text = blockNumberRequest.Result.Value.ToString();
    }
}

5、ETH转账的简单实现

为了支持ETH转账， Nethereum 提供了一个特定的 Unity 请求，EthTransferUnityRequest.

EthTransferUnityRequest 使用我们的以太坊客户端的“url”、能够签署交易的私钥和我们的帐户 地址（与私钥相同）进行实例化。

var  url  =  " http://localhost:8545 " ;
var  privateKey  =  " 0xb5b1870957d373ef0eeffecc6e4812c0fd08f554b37b233526acc331bf1544f7 " ; 
var  ethTransfer  =  new  EthTransferUnityRequest ( url , privateKey , " YOURCHAINID " );

一旦我们的请求被实例化，就可以使用传统模式启动传输，下面的代码设置 2 Gwei 作为gas价格:

var receivingAddress = "0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe";
yield return ethTransfer.TransferEther(receivingAddress, 1.1m, 2);

在这里，我们指定了接收地址、发送量和可选的 gas 价格。该请求将自动将 gas 价格转换为 Wei。

我们可以在之后验证是否有任何异常，如下所示：

if (ethTransfer.Exception != null)
{
    Debug.Log(ethTransfer.Exception.Message);
    yield break;
}

如果没有发生错误，我们可以每 2 秒从请求和轮询中检索交易哈希以等待交易确认：

var transactionHash = ethTransfer.Result;
//create a poll to get the receipt when mined
var transactionReceiptPolling = new TransactionReceiptPollingRequest(url);
//checking every 2 seconds for the receipt
yield return transactionReceiptPolling.PollForReceipt(transactionHash, 2);

最后，我们可以使用EthGetBalanceUnityRequest检查收款账户的余额。请注意，我们在执行 请求时声明想要最新块记录的余额。

var balanceRequest = new EthGetBalanceUnityRequest(url);
yield return balanceRequest.SendRequest(receivingAddress, BlockParameter.CreateLatest());

可以使用默认的 Wei UnitConvertor 将 Wei 中的结果转换为 Eth：

Debug.Log("Balance of account:" + UnitConversion.Convert.FromWei(balanceRequest.Result.Value));

6、EIP 1559 使用建议

以下是使用协程、TimePreference、MedianFeeHistory 或 LegacyMode 提供的费用建议策略以使用 旧模式或与其他链一起使用的一些示例。

要使用 LegacyMode，你必须提供 GasPrice，或者可以通过设置UseLegacyAsDefault为 true 来强制 LegacyMode：

if (feeStrategy == FeeStrategy.TimePreference)
 {
     Debug.Log("Time Preference");
     var timePreferenceFeeSuggestion = new TimePreferenceFeeSuggestionUnityRequestStrategy(Url);

yield return timePreferenceFeeSuggestion.SuggestFees();

if (timePreferenceFeeSuggestion.Exception != null)
     {
         Debug.Log(timePreferenceFeeSuggestion.Exception.Message);
         yield break;
     }

//lets get the first one so it is higher priority
     Debug.Log(timePreferenceFeeSuggestion.Result.Length);
     if (timePreferenceFeeSuggestion.Result.Length > 0)
     {
         Debug.Log(timePreferenceFeeSuggestion.Result[0].MaxFeePerGas);
         Debug.Log(timePreferenceFeeSuggestion.Result[0].MaxPriorityFeePerGas);
     }
     var fee = timePreferenceFeeSuggestion.Result[0];

yield return ethTransfer.TransferEther(receivingAddress, Amount, fee.MaxPriorityFeePerGas.Value, fee.MaxFeePerGas.Value);
     if (ethTransfer.Exception != null)
     {
         Debug.Log(ethTransfer.Exception.Message);
         yield break;
     }
 }


 if(feeStrategy == FeeStrategy.MedianFeeHistory)
 {
     Debug.Log("MedianFeeHistory mode");
     var medianPriorityFeeStrategy = new MedianPriorityFeeHistorySuggestionUnityRequestStrategy(Url);

yield return medianPriorityFeeStrategy.SuggestFee();

if (medianPriorityFeeStrategy.Exception != null)
     {
         Debug.Log(medianPriorityFeeStrategy.Exception.Message);
         yield break;
     }

Debug.Log(medianPriorityFeeStrategy.Result.MaxFeePerGas);
     Debug.Log(medianPriorityFeeStrategy.Result.MaxPriorityFeePerGas);

var fee = medianPriorityFeeStrategy.Result;

yield return ethTransfer.TransferEther(receivingAddress, Amount, fee.MaxPriorityFeePerGas.Value, fee.MaxFeePerGas.Value);
     if (ethTransfer.Exception != null)
     {
         Debug.Log(ethTransfer.Exception.Message);
         yield break;
     }
 }

if (feeStrategy == FeeStrategy.Legacy)
 {
     Debug.Log("Legacy mode");
     //I am forcing the legacy mode but also I am including the gas price
     ethTransfer.UseLegacyAsDefault = true;

yield return ethTransfer.TransferEther(receivingAddress, Amount, GasPriceGwei);

if (ethTransfer.Exception != null)
     {
         Debug.Log(ethTransfer.Exception.Message);
         yield break;
     }

}

7、智能合约定义声明

在游戏中实现智能合约支持的第一步是包含我们的智能合约定义，这可以是使用 vscode solidity 扩展 或控制台代码生成工具生成的代码：

//Deployment contract object definition
public partial class EIP20Deployment : EIP20DeploymentBase
{
    public EIP20Deployment() : base(BYTECODE) { }
    public EIP20Deployment(string byteCode) : base(byteCode) { }
}

public class EIP20DeploymentBase : ContractDeploymentMessage
{
    public static string BYTECODE = "608060405234801561001057600080fd5b506040516107843803806107848339810160409081528151602080840151838501516060860151336000908152808552959095208490556002849055908501805193959094919391019161006991600391860190610096565b506004805460ff191660ff8416179055805161008c906005906020840190610096565b5050505050610131565b828054600181600116156101000203166002900490600052602060002090601f016020900481019282601f106100d757805160ff1916838001178555610104565b82800160010185558215610104579182015b828111156101045782518255916020019190600101906100e9565b50610110929150610114565b5090565b61012e91905b80821115610110576000815560010161011a565b90565b610644806101406000396000f3006080604052600436106100ae5763ffffffff7c010000000000000000000000000000000000000000000000000000000060003504166306fdde0381146100b3578063095ea7b31461013d57806318160ddd1461017557806323b872dd1461019c57806327e235e3146101c6578063313ce567146101e75780635c6581651461021257806370a082311461023957806395d89b411461025a578063a9059cbb1461026f578063dd62ed3e14610293575b600080fd5b3480156100bf57600080fd5b506100c86102ba565b6040805160208082528351818301528351919283929083019185019080838360005b838110156101025781810151838201526020016100ea565b50505050905090810190601f16801561012f5780820380516001836020036101000a031916815260200191505b509250505060405180910390f35b34801561014957600080fd5b50610161600160a060020a0360043516602435610348565b604080519115158252519081900360200190f35b34801561018157600080fd5b5061018a6103ae565b60408051918252519081900360200190f35b3480156101a857600080fd5b50610161600160a060020a03600435811690602435166044356103b4565b3480156101d257600080fd5b5061018a600160a060020a03600435166104b7565b3480156101f357600080fd5b506101fc6104c9565b6040805160ff9092168252519081900360200190f35b34801561021e57600080fd5b5061018a600160a060020a03600435811690602435166104d2565b34801561024557600080fd5b5061018a600160a060020a03600435166104ef565b34801561026657600080fd5b506100c861050a565b34801561027b57600080fd5b50610161600160a060020a0360043516602435610565565b34801561029f57600080fd5b5061018a600160a060020a03600435811690602435166105ed565b6003805460408051602060026001851615610100026000190190941693909304601f810184900484028201840190925281815292918301828280156103405780601f1061031557610100808354040283529160200191610340565b820191906000526020600020905b81548152906001019060200180831161032357829003601f168201915b505050505081565b336000818152600160209081526040808320600160a060020a038716808552908352818420869055815186815291519394909390927f8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925928290030190a350600192915050565b60025481565b600160a060020a03831660008181526001602090815260408083203384528252808320549383529082905281205490919083118015906103f45750828110155b15156103ff57600080fd5b600160a060020a038085166000908152602081905260408082208054870190559187168152208054849003905560001981101561046157600160a060020a03851660009081526001602090815260408083203384529091529020805484900390555b83600160a060020a031685600160a060020a03167fddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef856040518082815260200191505060405180910390a3506001949350505050565b60006020819052908152604090205481565b60045460ff1681565b600160209081526000928352604080842090915290825290205481565b600160a060020a031660009081526020819052604090205490565b6005805460408051602060026001851615610100026000190190941693909304601f810184900484028201840190925281815292918301828280156103405780601f1061031557610100808354040283529160200191610340565b3360009081526020819052604081205482111561058157600080fd5b3360008181526020818152604080832080548790039055600160a060020a03871680845292819020805487019055805186815290519293927fddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef929181900390910190a350600192915050565b600160a060020a039182166000908152600160209081526040808320939094168252919091522054905600a165627a7a7230582084c618322109054a21a57e27075384a6172ab854e4b2c2d35062a964a6bf593f0029";

public EIP20DeploymentBase() : base(BYTECODE) { }

public EIP20DeploymentBase(string byteCode) : base(byteCode) { }

[Parameter("uint256", "_initialAmount", 1)]

public BigInteger InitialAmount { get; set; }

[Parameter("string", "_tokenName", 2)]

public string TokenName { get; set; }

[Parameter("uint8", "_decimalUnits", 3)]

public byte DecimalUnits { get; set; }

[Parameter("string", "_tokenSymbol", 4)]

public string TokenSymbol { get; set; }

}

[Function("transfer", "bool")]
public class TransferFunctionBase : FunctionMessage
{
    [Parameter("address", "_to", 1)]
    public string To { get; set; }
    [Parameter("uint256", "_value", 2)]
    public BigInteger Value { get; set; }
}

public partial class TransferFunction : TransferFunctionBase
{
}

[Function("balanceOf", "uint256")]
public class BalanceOfFunction : FunctionMessage
{
    [Parameter("address", "_owner", 1)]
    public string Owner { get; set; }
}

[FunctionOutput]
public class BalanceOfFunctionOutput : IFunctionOutputDTO
{
    [Parameter("uint256", 1)]
    public int Balance { get; set; }
}

[Event("Transfer")]
public class TransferEventDTOBase : IEventDTO
{
    [Parameter("address", "_from", 1, true)]
    public virtual string From { get; set; }

[Parameter("address", "_to", 2, true)]
    public virtual string To { get; set; }

[Parameter("uint256", "_value", 3, false)]
    public virtual BigInteger Value { get; set; }
}

public partial class TransferEventDTO : TransferEventDTOBase
{
    public static EventABI GetEventABI()
    {
        return EventExtensions.GetEventABI<TransferEventDTO>();
    }
}

8、智能合约部署

为了部署智能合约，我们使用节点 url 和签名信息创建一个 TransactionSignedUnityRequest。 创建一个新的 EIP20Deployment 合约定义，我们设置构造函数参数并发送交易。最后，我们创建 TransactionReceiptPollingRequest 来轮询交易收据并从交易收据中检索新部署的合约地址：

var url = "http://localhost:8545";
var privateKey = "0xb5b1870957d373ef0eeffecc6e4812c0fd08f554b37b233526acc331bf1544f7";
var account = "0x12890d2cce102216644c59daE5baed380d84830c";
//initialising the transaction request sender

var transactionRequest = new TransactionSignedUnityRequest(url, privateKey, "YOURCHAINID");

var deployContract = new EIP20Deployment()
{
    InitialAmount = 10000,
    FromAddress = account,
    TokenName = "TST",
    TokenSymbol = "TST"
};

//deploy the contract
yield return transactionRequest.SignAndSendDeploymentContractTransaction<EIP20DeploymentBase>(deployContract);

if (transactionRequest.Exception != null)
{
    Debug.Log(transactionRequest.Exception.Message);
    yield break;
}

var transactionHash = transactionRequest.Result;
Debug.Log("Deployment transaction hash:" + transactionHash);

//create a poll to get the receipt when mined
var transactionReceiptPolling = new TransactionReceiptPollingRequest(url);

//checking every 2 seconds for the receipt
yield return transactionReceiptPolling.PollForReceipt(transactionHash, 2);

var deploymentReceipt = transactionReceiptPolling.Result;

Debug.Log("Deployment contract address:" + deploymentReceipt.ContractAddress);

9、查询智能合约

要查询智能合约，我们需要创建一个提供 FunctionType 和 ReturnType 的新 QueryUnityRequest。 然后我们将执行查询，查询结果 Result 对象将为我们提供已经解码的合约的输出：

//Query request using our acccount and the contracts address (no parameters needed and default values)
var queryRequest = new QueryUnityRequest<BalanceOfFunction, BalanceOfFunctionOutput>(url, account);
yield return queryRequest.Query(new BalanceOfFunction(){Owner = account}, deploymentReceipt.ContractAddress);

//Getting the dto response already decoded
var dtoResult = queryRequest.Result;
Debug.Log(dtoResult.Balance);

10、转账交易

发送交易以便与与智能合约进行交互的步骤类似于部署。我们首先创建一个 TransactionSignedUnityRequest 和包含任何参数的函数，一旦发送交易，我们会轮询确认交易成功的交易收据。

使用交易收据，我们可以解码该交易的任何日志/事件：

var transactionTransferRequest = new TransactionSignedUnityRequest(url, privateKey, "YOURCHAINID");
var newAddress = "0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe";


var transactionMessage = new TransferFunction
{
    FromAddress = account,
    To = newAddress,
    Value = 1000,
};

yield return transactionTransferRequest.SignAndSendTransaction(transactionMessage, deploymentReceipt.ContractAddress);
var transactionTransferHash = transactionTransferRequest.Result;

Debug.Log("Transfer txn hash:" + transactionHash);

transactionReceiptPolling = new TransactionReceiptPollingRequest(url);
yield return transactionReceiptPolling.PollForReceipt(transactionTransferHash, 2);
var transferReceipt = transactionReceiptPolling.Result;

var transferEvent = transferReceipt.DecodeAllEvents<TransferEventDTO>();
Debug.Log("Transferd amount from event: " + transferEvent[0].Event.Value);

11、日志和事件

为了检索智能合约的日志/事件，我们使用 EthGetLogsUnityRequest 和特定于我们事件的 FilterInput。 可以使用 EventDTO 扩展 GetEventABI() 创建 FilterInputs。一旦我们生成了请求，我们就可以使用 Result.DecodeAllEvents 扩展方法解码所有匹配的事件。

var getLogsRequest = new EthGetLogsUnityRequest(url);
var eventTransfer = TransferEventDTO.GetEventABI();
yield return getLogsRequest.SendRequest(eventTransfer.CreateFilterInput(deploymentReceipt.ContractAddress, account));
var eventDecoded = getLogsRequest.Result.DecodeAllEvents<TransferEventDTO>();
Debug.Log("Transferd amount from get logs event: " + eventDecoded[0].Event.Value);

原文链接：Introduction to Unity in Nethereum

汇智网翻译整理，转载请标明出处