DAPP流动性质押模式挖矿系统开发（稳定版）及源码功能

　　智能合约在区块链上的可执行代码是一种类似汇编语言的指令集，这些指令集通过EVM的解释和执行，对区块链的状态进行读写，实现合约规定的业务逻辑。Therefore,through Solidity,a high-level programming language,and Solidity compiler,you can compile High-level programming language into assembly instruction set code,and then deploy it to the blockchain for execution.

　　一套完整的区块链DAPP，除智能合约这些可以查询和改变区块链状态的代码外，还需要用户操作界面及连接用户操作与智能合约代码的接口。

　　pragma solidity^0.8.0;

　　import"../IERC721.sol";

　　/**

　　*title ERC-721 Non-Fungible Token Standard,optional enumeration extension

　　*dev See https://eips.ethereum.org/EIPS/eip-721

　　*/

　　interface IERC721Enumerable is IERC721{

　　/**

　　*dev Returns the total amount of tokens stored by the contract.

　　*返回NFT总量

　　*/

　　function totalSupply()external view returns(uint256);

　　/**

　　*dev Returns a token ID owned by`owner`at a given`index`of its token list.

　　*Use along with{balanceOf}to enumerate all of``owner``'s tokens.

　　*所有者可以一次拥有多个的NFT,此函数返回_owner拥有的NFT列表中对应索引的tokenId

　　*/

　　function tokenOfOwnerByIndex(address owner,uint256 index)external view returns(uint256 tokenId);

　　/**

　　*dev Returns a token ID at a given`index`of all the tokens stored by the contract.

　　*Use along with{totalSupply}to enumerate all tokens.

　　*通过索引返回对应的tokenId

　　*/

　　function tokenByIndex(uint256 index)external view returns(uint256);

　　}