你如何設置錢包可以鑄造的最大 NFT 數量？

August 10, 2022

contract xyz is ERC721, ERC721Enumerable, ERC721URIStorage, Ownable {
   using Counters for Counters.Counter;

   Counters.Counter private _tokenIdCounter;
   
   uint256 public constant maxSupply = 9999;
   uint256 public constant userLimit = 1;
   mapping(address =&gt; uint) public walletMints;

   constructor() ERC721("xyz", "xyz") {}

   function safeMint(address to, string memory uri) public onlyOwner {
       require(_tokenIdCounter.current() &lt;= maxSupply, "I'm sorry we reached the cap");
       uint256 tokenId = _tokenIdCounter.current();
       _tokenIdCounter.increment();
       _safeMint(to, tokenId);
       _setTokenURI(tokenId, uri);
   }

我有檢查和映射錢包地址的契約，但我不知道如何在 mint 函式中寫入如何將錢包限制為僅 mint 1 nft。

我目前的猜測是它類似於“require(walletMints

$$ msg.sender $$<= 使用者限制“？任何幫助表示讚賞！

contract xyz is ERC721, ERC721Enumerable, ERC721URIStorage, Ownable {
   using Counters for Counters.Counter;

   Counters.Counter private _tokenIdCounter;
   
   uint256 public constant maxSupply = 9999;
   uint256 public constant userLimit = 1;
   mapping(address =&gt; uint) public walletMints;
   

   constructor() ERC721("xyz", "xyz") {}

   function safeMint(address to, string memory uri) public onlyOwner {
       require(_tokenIdCounter.current() &lt;= maxSupply, "I'm sorry we reached the cap");
      require(walletMints[msg.sender] &lt;= userLimit, "I'm sorry only one NFT per user");
       uint256 tokenId = _tokenIdCounter.current();
       _tokenIdCounter.increment();
       _safeMint(to, tokenId);
       _setTokenURI(tokenId, uri);
   }

你應該使用函式’balanceOf’或’balances’狀態變數。（它們返回一個地址擁有的 NFT 數量）。

contract xyz is ERC721, ERC721Enumerable, ERC721URIStorage, Ownable {
using Counters for Counters.Counter;

Counters.Counter private _tokenIdCounter;

uint256 public constant maxSupply = 9999;
uint256 public constant userLimit = 1;
mapping(address =&gt; uint) public walletMints;

constructor() ERC721("xyz", "xyz") {}

function safeMint(address to, string memory uri) public onlyOwner {
   require(_tokenIdCounter.current() &lt;= maxSupply, "I'm sorry we reached the cap");
   require(balanceOf(to) &lt;= userLimit ,'user limit error maessage')
   uint256 tokenId = _tokenIdCounter.current();
   _tokenIdCounter.increment();
   _safeMint(to, tokenId);
   _setTokenURI(tokenId, uri);
}