* 

 //ERC777.solfunction_send(address from,address to,uint256 amount,bytes memory userData,bytes memory operatorData,bool requireReceptionAck) internal { require(from != address(0), "ERC777: send from the zero address"); require(to != address(0), "ERC777: send to the zero address"); address operator =_msgSender(); // 调用发送钩子 _callTokensToSend(operator, from, to, amount, userData, operatorData); _move(operator, from, to, amount, userData, operatorData); // 调用接收钩子 _callTokensReceived(operator, from, to, amount, userData, operatorData, requireReceptionAck);} 

 //ERC777.sol// 发送钩子 function_callTokensToSend(address operator,address from,address to,uint256 amount,bytes memory userData,bytes memory operatorData) private { // 获取发送账户的接口地址 address implementer =_ERC1820_REGISTRY.getInterfaceImplementer(from,_TOKENS_SENDER_INTERFACE_HASH); if (implementer != address(0)) { // 执行接口地址的 tokensToSend 方法 IERC777Sender(implementer).tokensToSend(operator, from, to, amount, userData, operatorData); }}// 接收钩子 function_callTokensReceived(address operator,address from,address to,uint256 amount,bytes memory userData,bytes memory operatorData,bool requireReceptionAck) private { // 获取接收账户的接口地址 address implementer =_ERC1820_REGISTRY.getInterfaceImplementer(to,_TOKENS_RECIPIENT_INTERFACE_HASH); if (implementer != address(0)) { // 执行接口地址的 tokensReceived 方法 IERC777Recipient(implementer).tokensReceived(operator, from, to, amount, userData, operatorData); } else if (requireReceptionAck) { // 如果 requireReceptionAck 为 true 则必须执行接口方法 , 以防止代币被锁死 require(!to.isContract(), "ERC777: token recipient contract has no implementer for ERC777TokensRecipient"); }} 

 //ERC1820.sol/// @notice 如果合约代表某个其他地址实现接口，则返回 Magic 值。bytes32 constant internal ERC1820_ACCEPT_MAGIC = keccak256(abi.encodePacked("ERC1820_ACCEPT_MAGIC")); /// @notice 设置某个地址的接口由哪个合约实现，需要由管理员来设置。（每个地址是他自己的管理员，直到设置了一个新的地址）。/// @param_addr 待设置的关联接口的地址（如果 '_addr' 是零地址，则假定为 'msg.sender'）/// @param_interfaceHash 接口，它是接口名称字符串的 keccak256 哈希值 /// 例如 : 'web3.utils.keccak256("ERC777TokensRecipient")' 表示 'ERC777TokensRecipient' 接口。/// @param_implementer 为地址 '_addr' 实现了 '_interfaceHash' 接口的合约地址 function setInterfaceImplementer(address_addr, bytes32_interfaceHash, address_implementer) external { address addr =_addr == address(0) ? msg.sender :_addr; require(getManager(addr) == msg.sender, "Not the manager"); require(!isERC165Interface(_interfaceHash), "Must not be an ERC165 hash"); if (_implementer != address(0) &&_implementer != msg.sender) { // 调用接口合约的 canImplementInterfaceForAddress 方法 , 验证合约是否同意成为账户的接口 require( ERC1820ImplementerInterface(_implementer) .canImplementInterfaceForAddress(_interfaceHash, addr) == ERC1820_ACCEPT_MAGIC, "Does not implement the interface" ); } interfaces[addr][_interfaceHash] =_implementer; emit InterfaceImplementerSet(addr,_interfaceHash,_implementer);} 

 //TokensRecipient.solpragma solidity ^0.5.0; import "@openzeppelin/contracts/ownership/Ownable.sol";import "@openzeppelin/contracts/token/ERC777/IERC777Recipient.sol";import "@openzeppelin/contracts/introspection/ERC1820Implementer.sol";import "@openzeppelin/contracts/introspection/IERC1820Registry.sol";import "@openzeppelin/contracts/token/ERC777/IERC777.sol";import "@openzeppelin/contracts/math/SafeMath.sol"; contract TokensRecipient is ERC1820Implementer, IERC777Recipient, Ownable { bool private allowTokensReceived; using SafeMath for uint256; // keccak256("ERC777TokensRecipient") bytes32 private constant TOKENS_RECIPIENT_INTERFACE_HASH = 0xb281fc8c12954d22544db45de3159a39272895b169a852b314f9cc762e44c53b; mapping(address => address) public token; mapping(address => address) public operator; mapping(address => address) public from; mapping(address => address) public to; mapping(address => uint256) public amount; mapping(address => bytes) public data; mapping(address => bytes) public operatorData; mapping(address => uint256) public balanceOf; //ERC1820 注册表合约地址 , 全网统一 IERC1820Registry internal constant ERC1820_REGISTRY = IERC1820Registry( 0x1820a4B7618BdE71Dce8cdc73aAB6C95905faD24 ); constructor(bool_setInterface) public { if (_setInterface) { // 为合约自身也注册一个接口 , 如果这个合约可以接收代币就用得到 ERC1820_REGISTRY.setInterfaceImplementer( address(this), TOKENS_RECIPIENT_INTERFACE_HASH, address(this) ); } _registerInterfaceForAddress(TOKENS_RECIPIENT_INTERFACE_HASH, msg.sender); allowTokensReceived = true; } function tokensReceived( address_operator, address_from, address_to, uint256_amount, bytes calldata_data, bytes calldata_operatorData ) external { require(allowTokensReceived, "Receive not allowed"); token[_from] = msg.sender; operator[_from] =_operator; from[_from] =_from; to[_from] =_to; amount[_from] = amount[_from].add(_amount); data[_from] =_data; operatorData[_from] =_operatorData; balanceOf[_from] = IERC777(msg.sender).balanceOf(_from); balanceOf[_to] = IERC777(msg.sender).balanceOf(_to); } function acceptTokens() public onlyOwner { allowTokensReceived = true; } function rejectTokens() public onlyOwner { allowTokensReceived = false; }} 

 const assert = require('assert');const { contract, accounts, web3 } = require('@openzeppelin/test-environment');const { ether, makeInterfaceId, singletons, expectEvent } = require('@openzeppelin/test-helpers');const ERC777Contract = contract.fromArtifact("ERC777Contract");const TokensRecipient = contract.fromArtifact("TokensRecipient"); [owner, sender, receiver] = accounts;const initialSupply = '1000000000';const defaultOperators = [sender];let amount = '100';const userData = web3.utils.toHex('A gift');describe("ERC777 代币 ", function () { it(' 实例化 ERC1820 注册表 ', async function () { ERC1820RegistryInstance = await singletons.ERC1820Registry(owner); }); it(' 布署代币合约 ', async function () { ERC777Param = [ // 构造函数的参数 "My Golden Coin", // 代币名称 "MGC", // 代币缩写 ether(initialSupply), // 发行总量 defaultOperators // 默认操作员 ] ERC777Instance = await ERC777Contract.new(...ERC777Param, { from: owner }); }); it(' 布署接受接口合约 ', async function () { TokensRecipientInstance = await TokensRecipient.new(true, { from: receiver }); });});  describe(" 注册 ERC1820 接口 ", function () { it(' 注册代币接收接口 : setInterfaceImplementer() ERC777TokensRecipient', async function () { await ERC1820RegistryInstance.setInterfaceImplementer( receiver, makeInterfaceId.ERC1820('ERC777TokensRecipient'), TokensRecipientInstance.address, { from: receiver } ); }); it(' 验证代币接收接口 : setInterfaceImplementer() ERC777TokensRecipient', async function () { assert.equal(TokensRecipientInstance.address, await ERC1820RegistryInstance.getInterfaceImplementer( receiver, makeInterfaceId.ERC1820('ERC777TokensRecipient') )) });}); describe(" 测试 ERC777 合约的方法 ", function () { //send() it(' 发送方法 : send()', async function () { let receipt = await ERC777Instance.send(receiver, ether(amount), userData, { from: owner }); expectEvent(receipt, 'Sent', { operator: owner, from: owner, to: receiver, amount: ether(amount), data: userData, operatorData: null }); expectEvent(receipt, 'Transfer', { from: owner, to: receiver, value: ether(amount), }); }); it(' 验证接收接口 : TokensRecipient()', async function () { assert.equal(ERC777Instance.address, await TokensRecipientInstance.token(owner)); assert.equal(owner, await TokensRecipientInstance.operator(owner)); assert.equal(owner, await TokensRecipientInstance.from(owner)); assert.equal(receiver, await TokensRecipientInstance.to(owner)); assert.equal(ether(amount).toString(), (await TokensRecipientInstance.amount(owner)).toString()); assert.equal(userData, await TokensRecipientInstance.data(owner)); assert.equal(null, await TokensRecipientInstance.operatorData(owner)); assert.equal(ether((parseInt(initialSupply) - parseInt(amount)).toString()).toString(), (await TokensRecipientInstance.balanceOf(owner)).toString()); assert.equal(ether(amount), (await TokensRecipientInstance.balanceOf(receiver)).toString()); });});describe(" 测试发送和接收接口的拒绝方法 ", function () { it(' 设置拒绝接收 : rejectTokens()', async function () { await TokensRecipientInstance.rejectTokens({ from: receiver }); }); it(' 验证代币接收者拒绝接收 : transfer()', async function () { await assert.rejects(ERC777Instance.transfer(receiver, ether(amount), { from: owner }), /Receive not allowed/); });});