如何使用C#获取智能合约报价者的计数器

Question

我正在尝试使用 OpenSea api 创建一个列表，其中一个参数是“counter”。

他们（OpenSea）说，如果你不确定当前的计数器，可以从 Etherscan 上的合约中读取。

我四处询问，似乎你可以使用 Solidity 通过 getCounter() 获得这个计数器。

我使用 C# - 我该怎么做？

我尝试使用合约 ABI - 查找并调用一个名为 getCounter 或类似函数的函数，但 ABI 中没有这样的东西。

我有办法做到这一点吗？

编辑：这里是 C# 代码，应该调用合约 ABI 中的 getCounter 函数并获取计数器。问题是 ABI 不包含这样的功能。

using System;
using System.Net.Http;
using System.Numerics;
using System.Threading.Tasks;
using Newtonsoft.Json.Linq;

public class ContractInteraction
{
    private readonly string contractAddress;
    private readonly JArray contractAbi;
    private readonly string walletAddress;

    public ContractInteraction(string contractAddress, JArray contractAbi, string walletAddress)
    {
        this.contractAddress = contractAddress;
        this.contractAbi = contractAbi;
        this.walletAddress = walletAddress;
    }

    public async Task<int> GetCounter()
    {
        // Replace this URL with the Ethereum node endpoint you're using
        string ethereumNodeUrl = "https://mainnet.infura.io/v3/your-infura-key";

        // You might need to adjust this based on the specific function in your contract that returns the counter
        string methodName = "getCounter";

        // Build the JSON-RPC request
        var rpcRequest = new
        {
            jsonrpc = "2.0",
            method = "eth_call",
            @params = new
            {
                to = contractAddress,
                data = GetFunctionCallData(methodName),
            },
            id = 1
        };

        using (var client = new HttpClient())
        {
            var response = await client.PostAsJsonAsync(ethereumNodeUrl, rpcRequest);
            var responseData = await response.Content.ReadAsStringAsync();
            var result = JObject.Parse(responseData)["result"].ToString();

            // Convert the hex result to an integer
            int counter = int.Parse(result, System.Globalization.NumberStyles.HexNumber);
            return counter;
        }
    }

    private string GetFunctionCallData(string methodName)
    {
        var function = contractAbi
            .Where(token => token["type"].ToString() == "function" && token["name"].ToString() == methodName)
            .FirstOrDefault();

        if (function == null)
        {
            throw new InvalidOperationException($"Function '{methodName}' not found in contract ABI.");
        }

        string signature = function["signature"].ToString();
        return $"{signature.Substring(0, 10)}{walletAddress.Substring(2).PadLeft(64, '0')}";
    }
}

class Program
{
    static async Task Main()
    {
        string contractAddress = "0xYourContractAddress";
        string contractAbiFilePath = "path/to/your/abi-file.txt";
        string yourWalletAddress = "0xYourWalletAddress";

        string abiJson = System.IO.File.ReadAllText(contractAbiFilePath);
        JArray abiArray = JArray.Parse(abiJson);

        ContractInteraction contractInteraction = new ContractInteraction(contractAddress, abiArray, yourWalletAddress);

        int counter = await contractInteraction.GetCounter();
        Console.WriteLine($"Counter: {counter}");
    }
}

Answer 1

尝试使用 Nethereum 库。虽然我无法测试它，但下面的代码可能会给你一些想法。

string url = "https://mainnet.infura.io/v3/YOUR_PROJECT_ID";

// Address of the contract
string contractAddress = "0x...";

// Contract ABI
string abi= @"[...ABI JSON...]";

var web3 = new Web3(url);
var contract = web3.Eth.GetContract(abi, contractAddress);

var function = contract.GetFunction("getCounter");
var result = await function.CallAsync<string>(<parameters if any>);
return result;