小编Jos*_*ios的帖子

上下文：坚固性^0.8.0

目的：实现一个简单的NFT合约

问题：错误抛出我必须指定虚拟/覆盖关键字，但我已经完成了。ERC721URIStorage继承自ERC721

详细1：

TypeError: Derived contract must override function "_burn". Two or more base classes define function with same name and parameter types.
[...]
TypeError: Derived contract must override function "tokenURI". Two or more base classes define function with same name and parameter types.
    --> contracts/resp.sol:1185:1:

详细2：

TypeError: Derived contract must override function "_burn". Two or more base classes define function with same name and parameter types.
    --> contracts/resp.sol:1185:1:
     |
1185 | contract MyNFT is ERC721, Ownable, ERC721URIStorage { …