ERC721概念
NFT的标准实现,作为同质化代币的合约标准。具有存储元数据及拥有者,以及对应的查询、管理功能。
主要功能
-
事件 (Events):
Transfer
:当 NFT 被转移时触发。Approval
:当某个地址被授权管理 NFT 时触发。ApprovalForAll
:当某个地址被授权管理所有 NFT 时触发。
-
方法 (Functions):
balanceOf(address owner)
:查询某地址拥有的 NFT 数量。ownerOf(uint256 tokenId)
:查询某个 NFT 的持有者。approve(address to, uint256 tokenId)
:授权某个地址管理指定的 NFT。setApprovalForAll(address operator, bool approved)
:批量授权某个地址管理所有 NFT。getApproved(uint256 tokenId)
:查询某个 NFT 被授权的地址。isApprovedForAll(address owner, address operator)
:查询某个地址是否被批量授权。safeTransferFrom(address from, address to, uint256 tokenId)
:安全转移 NFT。tokenURI(uint256 tokenId)
:查询 NFT 的元数据 URI。
下面是一个标准的 ERC-721 代币合约的 ABI(Application Binary Interface),基于 OpenZeppelin 的实现:
[
{
"anonymous": false,
"inputs": [
{
"indexed": true,
"internalType": "address",
"name": "from",
"type": "address"
},
{
"indexed": true,
"internalType": "address",
"name": "to",
"type": "address"
},
{
"indexed": true,
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
}
],
"name": "Transfer",
"type": "event"
},
{
"anonymous": false,
"inputs": [
{
"indexed": true,
"internalType": "address",
"name": "owner",
"type": "address"
},
{
"indexed": true,
"internalType": "address",
"name": "approved",
"type": "address"
},
{
"indexed": true,
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
}
],
"name": "Approval",
"type": "event"
},
{
"anonymous": false,
"inputs": [
{
"indexed": true,
"internalType": "address",
"name": "owner",
"type": "address"
},
{
"indexed": true,
"internalType": "address",
"name": "operator",
"type": "address"
},
{
"indexed": false,
"internalType": "bool",
"name": "approved",
"type": "bool"
}
],
"name": "ApprovalForAll",
"type": "event"
},
{
"inputs": [
{
"internalType": "address",
"name": "to",
"type": "address"
},
{
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
}
],
"name": "approve",
"outputs": [],
"stateMutability": "nonpayable",
"type": "function"
},
{
"inputs": [
{
"internalType": "address",
"name": "owner",
"type": "address"
}
],
"name": "balanceOf",
"outputs": [
{
"internalType": "uint256",
"name": "",
"type": "uint256"
}
],
"stateMutability": "view",
"type": "function"
},
{
"inputs": [
{
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
}
],
"name": "getApproved",
"outputs": [
{
"internalType": "address",
"name": "",
"type": "address"
}
],
"stateMutability": "view",
"type": "function"
},
{
"inputs": [
{
"internalType": "address",
"name": "owner",
"type": "address"
},
{
"internalType": "address",
"name": "operator",
"type": "address"
}
],
"name": "isApprovedForAll",
"outputs": [
{
"internalType": "bool",
"name": "",
"type": "bool"
}
],
"stateMutability": "view",
"type": "function"
},
{
"inputs": [
{
"internalType": "address",
"name": "from",
"type": "address"
},
{
"internalType": "address",
"name": "to",
"type": "address"
},
{
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
}
],
"name": "safeTransferFrom",
"outputs": [],
"stateMutability": "nonpayable",
"type": "function"
},
{
"inputs": [
{
"internalType": "address",
"name": "from",
"type": "address"
},
{
"internalType": "address",
"name": "to",
"type": "address"
},
{
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
},
{
"internalType": "bytes",
"name": "_data",
"type": "bytes"
}
],
"name": "safeTransferFrom",
"outputs": [],
"stateMutability": "nonpayable",
"type": "function"
},
{
"inputs": [
{
"internalType": "address",
"name": "operator",
"type": "address"
},
{
"internalType": "bool",
"name": "approved",
"type": "bool"
}
],
"name": "setApprovalForAll",
"outputs": [],
"stateMutability": "nonpayable",
"type": "function"
},
{
"inputs": [
{
"internalType": "bytes4",
"name": "interfaceId",
"type": "bytes4"
}
],
"name": "supportsInterface",
"outputs": [
{
"internalType": "bool",
"name": "",
"type": "bool"
}
],
"stateMutability": "view",
"type": "function"
},
{
"inputs": [
{
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
}
],
"name": "ownerOf",
"outputs": [
{
"internalType": "address",
"name": "",
"type": "address"
}
],
"stateMutability": "view",
"type": "function"
},
{
"inputs": [],
"name": "name",
"outputs": [
{
"internalType": "string",
"name": "",
"type": "string"
}
],
"stateMutability": "view",
"type": "function"
},
{
"inputs": [],
"name": "symbol",
"outputs": [
{
"internalType": "string",
"name": "",
"type": "string"
}
],
"stateMutability": "view",
"type": "function"
},
{
"inputs": [
{
"internalType": "uint256",
"name": "tokenId",
"type": "uint256"
}
],
"name": "tokenURI",
"outputs": [
{
"internalType": "string",
"name": "",
"type": "string"
}
],
"stateMutability": "view",
"type": "function"
}
]