pragma solidity ^0.8.9; import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; import "@openzeppelin/contracts/utils/Counters.sol"; contract timeGenesisCard is ERC721URIStorage, Ownable{ using Counters for Counters.Counter; Counters.Counter private _tokenIdCounter; uint256 private immutable totalSupply=10000; //total 10000 uint256 private whiteUserNum; //whitelist amount

//nft uri
string private uri;

constructor() ERC721("Genesis Time Whale", "GTW"){}

address[125] private theseWhiteAddress;
mapping(address=>bool)public userIfWhitelist;

receive() external payable {}

//public mint
function mintTimeWhale()public payable{
    //limit total 10000
    require(_tokenIdCounter.current()<=totalSupply,"There are no NFTS available for mint anymore"); 
    uint256 tokenId = _tokenIdCounter.current();
    uint256 contractFee=price(msg.sender);
    userIfWhitelist[msg.sender] = false;
    require(msg.value > contractFee,"This address not enough paid");
    _safeMint(msg.sender, tokenId);
    _setTokenURI(tokenId, uri);
    _tokenIdCounter.increment(); //tokenId+1
}

//Add address to whitelist
function addUser(address _user) public onlyOwner{
    require(whiteUserNum < 2000, "number of users is limited to 200");
    require(userIfWhitelist[_user]==false, "This address has been whitelisted");
    theseWhiteAddress[whiteUserNum] = _user;
    whiteUserNum++;
    userIfWhitelist[_user] = true;
}

//Remove addresses from the whitelist
function removeWhitelist(address _user) public {
    require(userIfWhitelist[_user]==true,"not a whitelist");
    userIfWhitelist[_user] = false;
}

//fee
function price(address userAddress)public view returns(uint256){
    if(userIfWhitelist[userAddress]){
        //Whitelist 0.001 fee
        return 0.005 ether;
    }else{
        //Not whitelist 0.01 fee
        return 0.02 ether;
    }
}
}

require(msg.value > contractFee,"This address not enough paid");使用这句以前是可行的，最近试了下，开发账户还有99eth的，然后我测试msg.value>0，显示报错，也就是得到自身0eth，这是怎么回事呢？