有时候我们的到了合约的sol源代码，但是需要abi。通过abi调用合约中的方法。本文介绍几种方法。

solc编译

通过solc contract.sol --abi 即可获得abi。如下所示，在当前目录下存在两个sol文件，分别是Random.sol和Setup.sol。合约代码如下所示：
Randmon.sol

// SPDX-License-Identifier: UNLICENSED

pragma solidity 0.8.15;

contract Random {

    bool public solved = false;

    function _getRandomNumber() internal pure returns (uint256) {   // chosen by fair dice roll.
        return 4;                                                   // guaranteed to be random.
    }
    
    function solve(uint256 guess) public {
        require(guess == _getRandomNumber());
        solved = true;
    }
}

Setup.sol

// SPDX-License-Identifier: UNLICENSED

pragma solidity 0.8.15;

import "./Random.sol";

contract Setup {

    Random public random;

    constructor() {
        random = new Random();
    }

    function isSolved() public view returns (bool) {
        return random.solved();
    }
}

通过solc Setup.sol --abi得到输出如下：

======= Random.sol:Random =======
Contract JSON ABI
[{"inputs":[{"internalType":"uint256","name":"guess","type":"uint256"}],"name":"solve","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"solved","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"}]

======= Setup.sol:Setup =======
Contract JSON ABI
[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"isSolved","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"random","outputs":[{"internalType":"contract Random","name":"","type":"address"}],"stateMutability":"view","type":"function"}]

remix

通过将代码上传到remix，编译完成之后，在编译的右下角的按钮的地方也可以得到abi文件;

[
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "guess",
				"type": "uint256"
			}
		],
		"name": "solve",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	},
	{
		"inputs": [],
		"name": "solved",
		"outputs": [
			{
				"internalType": "bool",
				"name": "",
				"type": "bool"
			}
		],
		"stateMutability": "view",
		"type": "function"
	}
]

合约地址

如果知道了合约地址，并且合约是verify的，就可以直接在etherscan中获取到对应的abi。以无聊猴的nft合约地址为例.BoredApeYachtClub (BAYC),在这个页面就可以找到Contract ABI，复制即可。

参考

1. https://www.cloudhadoop.com/solidity-get-abi-json-file/