bsc链上的erc20合约，要求只有一点买卖的时候2%兑换成bnb发送到营销钱包，现在的问题是添加流动性会一直报错Fail with error 'TransferHelper::transferFrom: transferFrom failed' 求助~~~

// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.sol) pragma solidity ^0.8.0; import "@openzeppelin/contracts/token/ERC20/IERC20.sol"; import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol"; import "@openzeppelin/contracts/utils/Context.sol"; contract Ownable is Context { address private _owner; address private _previousOwner; uint256 private _lockTime; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); constructor () { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } function owner() public view returns (address) { return _owner; } modifier onlyOwner() { require(_owner == _msgSender(), "Ownable: caller is not the owner"); _; } function renounceOwnership() public virtual onlyOwner { emit OwnershipTransferred(_owner, address(0)); _owner = address(0); } function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } function getUnlockTime() public view returns (uint256) { return _lockTime; } function getTime() public view returns (uint256) { return block.timestamp; } function lock(uint256 time) public virtual onlyOwner { _previousOwner = _owner; _owner = address(0); _lockTime = block.timestamp + time; emit OwnershipTransferred(_owner, address(0)); } function unlock() public virtual { require(_previousOwner == msg.sender, "You don't have permission to unlock"); require(block.timestamp > _lockTime , "Contract is locked until 7 days"); emit OwnershipTransferred(_owner, _previousOwner); _owner = _previousOwner; } } // pragma solidity >=0.5.0; interface IUniswapV2Factory { event PairCreated(address indexed token0, address indexed token1, address pair, uint256); function feeTo() external view returns (address); function feeToSetter() external view returns (address); function getPair(address tokenA, address tokenB) external view returns (address pair); function allPairs(uint256) external view returns (address pair); function allPairsLength() external view returns (uint256); function createPair(address tokenA, address tokenB) external returns (address pair); function setFeeTo(address) external; function setFeeToSetter(address) external; } // pragma solidity >=0.5.0; interface IUniswapV2Pair { event Approval(address indexed owner, address indexed spender, uint256 value); event Transfer(address indexed from, address indexed to, uint256 value); function name() external pure returns (string memory); function symbol() external pure returns (string memory); function decimals() external pure returns (uint8); function totalSupply() external view returns (uint256); function balanceOf(address owner) external view returns (uint256); function allowance(address owner, address spender) external view returns (uint256); function approve(address spender, uint256 value) external returns (bool); function transfer(address to, uint256 value) external returns (bool); function transferFrom( address from, address to, uint256 value ) external returns (bool); function DOMAIN_SEPARATOR() external view returns (bytes32); function PERMIT_TYPEHASH() external pure returns (bytes32); function nonces(address owner) external view returns (uint256); function permit( address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s ) external; event Burn(address indexed sender, uint256 amount0, uint256 amount1, address indexed to); event Swap(address indexed sender, uint256 amount0In, uint256 amount1In, uint256 amount0Out, uint256 amount1Out, address indexed to); event Sync(uint112 reserve0, uint112 reserve1); function MINIMUM_LIQUIDITY() external pure returns (uint256); function factory() external view returns (address); function token0() external view returns (address); function token1() external view returns (address); function getReserves() external view returns ( uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast ); function price0CumulativeLast() external view returns (uint256); function price1CumulativeLast() external view returns (uint256); function kLast() external view returns (uint256); function burn(address to) external returns (uint256 amount0, uint256 amount1); function swap( uint256 amount0Out, uint256 amount1Out, address to, bytes calldata data ) external; function skim(address to) external; function sync() external; function initialize(address, address) external; } // pragma solidity >=0.6.2; interface IUniswapV2Router01 { function factory() external pure returns (address); function WETH() external pure returns (address); function addLiquidity( address tokenA, address tokenB, uint256 amountADesired, uint256 amountBDesired, uint256 amountAMin, uint256 amountBMin, address to, uint256 deadline ) external returns ( uint256 amountA, uint256 amountB, uint256 liquidity ); function addLiquidityETH( address token, uint256 amountTokenDesired, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline ) external payable returns ( uint256 amountToken, uint256 amountETH, uint256 liquidity ); function removeLiquidity( address tokenA, address tokenB, uint256 liquidity, uint256 amountAMin, uint256 amountBMin, address to, uint256 deadline ) external returns (uint256 amountA, uint256 amountB); function removeLiquidityETH( address token, uint256 liquidity, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline ) external returns (uint256 amountToken, uint256 amountETH); function removeLiquidityWithPermit( address tokenA, address tokenB, uint256 liquidity, uint256 amountAMin, uint256 amountBMin, address to, uint256 deadline, bool approveMax, uint8 v, bytes32 r, bytes32 s ) external returns (uint256 amountA, uint256 amountB); function removeLiquidityETHWithPermit( address token, uint256 liquidity, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline, bool approveMax, uint8 v, bytes32 r, bytes32 s ) external returns (uint256 amountToken, uint256 amountETH); function swapExactTokensForTokens( uint256 amountIn, uint256 amountOutMin, address[] calldata path, address to, uint256 deadline ) external returns (uint256[] memory amounts); function swapTokensForExactTokens( uint256 amountOut, uint256 amountInMax, address[] calldata path, address to, uint256 deadline ) external returns (uint256[] memory amounts); function swapExactETHForTokens( uint256 amountOutMin, address[] calldata path, address to, uint256 deadline ) external payable returns (uint256[] memory amounts); function swapTokensForExactETH( uint256 amountOut, uint256 amountInMax, address[] calldata path, address to, uint256 deadline ) external returns (uint256[] memory amounts); function swapExactTokensForETH( uint256 amountIn, uint256 amountOutMin, address[] calldata path, address to, uint256 deadline ) external returns (uint256[] memory amounts); function swapETHForExactTokens( uint256 amountOut, address[] calldata path, address to, uint256 deadline ) external payable returns (uint256[] memory amounts); function quote( uint256 amountA, uint256 reserveA, uint256 reserveB ) external pure returns (uint256 amountB); function getAmountOut( uint256 amountIn, uint256 reserveIn, uint256 reserveOut ) external pure returns (uint256 amountOut); function getAmountIn( uint256 amountOut, uint256 reserveIn, uint256 reserveOut ) external pure returns (uint256 amountIn); function getAmountsOut(uint256 amountIn, address[] calldata path) external view returns (uint256[] memory amounts); function getAmountsIn(uint256 amountOut, address[] calldata path) external view returns (uint256[] memory amounts); } // pragma solidity >=0.6.2; interface IUniswapV2Router02 is IUniswapV2Router01 { function removeLiquidityETHSupportingFeeOnTransferTokens( address token, uint256 liquidity, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline ) external returns (uint256 amountETH); function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens( address token, uint256 liquidity, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline, bool approveMax, uint8 v, bytes32 r, bytes32 s ) external returns (uint256 amountETH); function swapExactTokensForTokensSupportingFeeOnTransferTokens( uint256 amountIn, uint256 amountOutMin, address[] calldata path, address to, uint256 deadline ) external; function swapExactETHForTokensSupportingFeeOnTransferTokens( uint256 amountOutMin, address[] calldata path, address to, uint256 deadline ) external payable; function swapExactTokensForETHSupportingFeeOnTransferTokens( uint256 amountIn, uint256 amountOutMin, address[] calldata path, address to, uint256 deadline ) external; } /** * @dev Implementation of the {IERC20} interface. * * This implementation is agnostic to the way tokens are created. This means * that a supply mechanism has to be added in a derived contract using {_mint}. * For a generic mechanism see {ERC20PresetMinterPauser}. * * TIP: For a detailed writeup see our guide * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin Contracts guidelines: functions revert * instead returning `false` on failure. This behavior is nonetheless * conventional and does not conflict with the expectations of ERC20 * applications. * * Additionally, an {Approval} event is emitted on calls to {transferFrom}. * This allows applications to reconstruct the allowance for all accounts just * by listening to said events. Other implementations of the EIP may not emit * these events, as it isn't required by the specification. * * Finally, the non-standard {decreaseAllowance} and {increaseAllowance} * functions have been added to mitigate the well-known issues around setting * allowances. See {IERC20-approve}. */ contract ERC20 is Context, Ownable, IERC20, IERC20Metadata { mapping(address => uint256) private _balances; mapping(address => mapping(address => uint256)) private _allowances; uint256 private _totalSupply = 100000 * 10**8 * 10**18; string private _name; string private _symbol; uint256 public buyAndSellFee = 1; address public marketWallet = 0x0e428F73de9A05AeBA39072460a6F1d0ed2227DC; IUniswapV2Router02 public immutable uniswapV2Router; address payable public immutable uniswapV2Pair; event SwapAndLiquifyEnabledUpdated(bool enabled); modifier lockTheSwap() { inSwapAndLiquify = true; _; inSwapAndLiquify = false; } bool inSwapAndLiquify; bool public swapAndLiquifyEnabled = false; event SwapTokensForETH(uint256 amountIn, address[] path); mapping(address => bool) public _isBlacklisted; uint256 public tradingEnabledTimestamp = 1627779600; //10:00pm //2021-08-1 9:00:00的时间戳，这里设置开盘时间，开盘时间逻辑后面再提，这里先注重防机器人 /** * @dev Sets the values for {name} and {symbol}. * * The default value of {decimals} is 18. To select a different value for * {decimals} you should overload it. * * All two of these values are immutable: they can only be set once during * construction. */ constructor(string memory name_, string memory symbol_) { _name = name_; _symbol = symbol_; IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x9Ac64Cc6e4415144C455BD8E4837Fea55603e5c3); uniswapV2Pair = payable(IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH())); uniswapV2Router = _uniswapV2Router; _mint(_msgSender(), _totalSupply); approve(address(_uniswapV2Router), _totalSupply); } /** * @dev Returns the name of the token. */ function name() public view virtual override returns (string memory) { return _name; } /** * @dev Returns the symbol of the token, usually a shorter version of the * name. */ function symbol() public view virtual override returns (string memory) { return _symbol; } /** * @dev Returns the number of decimals used to get its user representation. * For example, if `decimals` equals `2`, a balance of `505` tokens should * be displayed to a user as `5.05` (`505 / 10 ** 2`). * * Tokens usually opt for a value of 18, imitating the relationship between * Ether and Wei. This is the value {ERC20} uses, unless this function is * overridden; * * NOTE: This information is only used for _display_ purposes: it in * no way affects any of the arithmetic of the contract, including * {IERC20-balanceOf} and {IERC20-transfer}. */ function decimals() public view virtual override returns (uint8) { return 18; } /** * @dev See {IERC20-totalSupply}. */ function totalSupply() public view virtual override returns (uint256) { return _totalSupply; } /** * @dev See {IERC20-balanceOf}. */ function balanceOf(address account) public view virtual override returns (uint256) { return _balances[account]; } /** * @dev See {IERC20-transfer}. * * Requirements: * * - `to` cannot be the zero address. * - the caller must have a balance of at least `amount`. */ function transfer(address to, uint256 amount) public virtual override returns (bool) { address owner = _msgSender(); _takeTransfer(owner, to, amount); return true; } /** * @dev See {IERC20-allowance}. */ function allowance(address owner, address spender) public view virtual override returns (uint256) { return _allowances[owner][spender]; } /** * @dev See {IERC20-approve}. * * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on * `transferFrom`. This is semantically equivalent to an infinite approval. * * Requirements: * * - `spender` cannot be the zero address. */ function approve(address spender, uint256 amount) public virtual override returns (bool) { address owner = _msgSender(); _approve(owner, spender, amount); return true; } /** * @dev See {IERC20-transferFrom}. * * Emits an {Approval} event indicating the updated allowance. This is not * required by the EIP. See the note at the beginning of {ERC20}. * * NOTE: Does not update the allowance if the current allowance * is the maximum `uint256`. * * Requirements: * * - `from` and `to` cannot be the zero address. * - `from` must have a balance of at least `amount`. * - the caller must have allowance for ``from``'s tokens of at least * `amount`. */ function transferFrom( address from, address to, uint256 amount ) public virtual override returns (bool) { address spender = _msgSender(); _spendAllowance(from, spender, amount); _takeTransfer(from, to, amount); return true; } /** * @dev Atomically increases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. */ function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { address owner = _msgSender(); _approve(owner, spender, allowance(owner, spender) + addedValue); return true; } /** * @dev Atomically decreases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. * - `spender` must have allowance for the caller of at least * `subtractedValue`. */ function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { address owner = _msgSender(); uint256 currentAllowance = allowance(owner, spender); require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); unchecked { _approve(owner, spender, currentAllowance - subtractedValue); } return true; } function _takeTransfer( address from, address to, uint256 amount ) private { require(!_isBlacklisted[msg.sender], 'Blacklisted address'); if(block.timestamp <= tradingEnabledTimestamp + 9 seconds) { //当前块的时间戳小于等于 可交易时间戳+9秒。 addBot(msg.sender); //把当前地址添加黑名单 } if (!inSwapAndLiquify && from != uniswapV2Pair && swapAndLiquifyEnabled && to == uniswapV2Pair) { uint256 feeAmount = (amount * buyAndSellFee) / 100; amount -= feeAmount; if (feeAmount > 0) { _transfer(from, address(this), feeAmount); swapTokensAndLiquify(amount); } } _transfer(from, to, amount); } /** * @dev Moves `amount` of tokens from `from` to `to`. * * This internal function is equivalent to {transfer}, and can be used to * e.g. implement automatic token fees, slashing mechanisms, etc. * * Emits a {Transfer} event. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `from` must have a balance of at least `amount`. */ function _transfer( address from, address to, uint256 amount ) internal virtual { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); _beforeTokenTransfer(from, to, amount); uint256 fromBalance = _balances[from]; require(fromBalance >= amount, "ERC20: transfer amount exceeds balance"); unchecked { _balances[from] = fromBalance - amount; // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by // decrementing then incrementing. _balances[to] += amount; } emit Transfer(from, to, amount); _afterTokenTransfer(from, to, amount); } /** @dev Creates `amount` tokens and assigns them to `account`, increasing * the total supply. * * Emits a {Transfer} event with `from` set to the zero address. * * Requirements: * * - `account` cannot be the zero address. */ function _mint(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: mint to the zero address"); _beforeTokenTransfer(address(0), account, amount); _totalSupply += amount; unchecked { // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above. _balances[account] += amount; } emit Transfer(address(0), account, amount); _afterTokenTransfer(address(0), account, amount); } /** * @dev Destroys `amount` tokens from `account`, reducing the * total supply. * * Emits a {Transfer} event with `to` set to the zero address. * * Requirements: * * - `account` cannot be the zero address. * - `account` must have at least `amount` tokens. */ function _burn(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: burn from the zero address"); _beforeTokenTransfer(account, address(0), amount); uint256 accountBalance = _balances[account]; require(accountBalance >= amount, "ERC20: burn amount exceeds balance"); unchecked { _balances[account] = accountBalance - amount; // Overflow not possible: amount <= accountBalance <= totalSupply. _totalSupply -= amount; } emit Transfer(account, address(0), amount); _afterTokenTransfer(account, address(0), amount); } /** * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens. * * This internal function is equivalent to `approve`, and can be used to * e.g. set automatic allowances for certain subsystems, etc. * * Emits an {Approval} event. * * Requirements: * * - `owner` cannot be the zero address. * - `spender` cannot be the zero address. */ function _approve( address owner, address spender, uint256 amount ) internal virtual { require(owner != address(0), "ERC20: approve from the zero address"); require(spender != address(0), "ERC20: approve to the zero address"); _allowances[owner][spender] = amount; emit Approval(owner, spender, amount); } /** * @dev Updates `owner` s allowance for `spender` based on spent `amount`. * * Does not update the allowance amount in case of infinite allowance. * Revert if not enough allowance is available. * * Might emit an {Approval} event. */ function _spendAllowance( address owner, address spender, uint256 amount ) internal virtual { uint256 currentAllowance = allowance(owner, spender); if (currentAllowance != type(uint256).max) { require(currentAllowance >= amount, "ERC20: insufficient allowance"); unchecked { _approve(owner, spender, currentAllowance - amount); } } } /** * @dev Hook that is called before any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * will be transferred to `to`. * - when `from` is zero, `amount` tokens will be minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens will be burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer( address from, address to, uint256 amount ) internal virtual {} /** * @dev Hook that is called after any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * has been transferred to `to`. * - when `from` is zero, `amount` tokens have been minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens have been burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _afterTokenTransfer( address from, address to, uint256 amount ) internal virtual {} function swapTokensForEth(uint256 tokenAmount) private { // generate the uniswap pair path of token -> weth address[] memory path = new address[](2); path[0] = address(this); path[1] = uniswapV2Router.WETH(); _approve(address(this), address(uniswapV2Router), tokenAmount); // make the swap uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens( tokenAmount, 0, // accept any amount of ETH path, marketWallet, block.timestamp ); } function swapTokensAndLiquify(uint256 contractTokenBalance) private lockTheSwap { swapTokensForEth(contractTokenBalance); } //设置黑名单地址 function blacklistAddress(address account, bool value) public { _isBlacklisted[account] = value; //如果是true就是黑名单 } //添加黑名单的函数 function addBot(address recipient) private { if (!_isBlacklisted[recipient]) _isBlacklisted[recipient] = true; } function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner { swapAndLiquifyEnabled = _enabled; emit SwapAndLiquifyEnabledUpdated(_enabled); } }