function _transfer(address sender, address recipient, uint256 amount) private { require(sender != address(0), "ERC20: transfer from the zero address"); require(recipient != address(0), "ERC20: transfer to the zero address");

 if (sender == uniswapV2Pair) { // Buy transaction uint256 fee = amount.mul(buyFee).div(100); uint256 transferAmount = amount.sub(fee); _balances[sender] = _balances[sender].sub(amount); _balances[recipient] = _balances[recipient].add(transferAmount); _balances[address(this)] = _balances[address(this)].add(fee); emit Transfer(sender, recipient, transferAmount); emit Transfer(sender, address(this), fee); } else if (recipient == uniswapV2Pair) { // Sell transaction uint256 fee = amount.mul(sellFee).div(100); uint256 transferAmount = amount.sub(fee); require( _balances[sender].sub(amount) >= _totalSupply.mul(1).div(1000), "ERC20: must retain at least 0.1% of balance" ); _balances[sender] = _balances[sender].sub(amount); _balances[recipient] = _balances[recipient].add(transferAmount); _balances[address(this)] = _balances[address(this)].add(fee); emit Transfer(sender, recipient, transferAmount); emit Transfer(sender, address(this), fee); } else { // Regular transfer require( _balances[sender].sub(amount) >= _totalSupply.mul(1).div(1000), "ERC20: must retain at least 0.1% of balance" ); _balances[sender] = _balances[sender].sub(amount); _balances[recipient] = _balances[recipient].add(amount); emit Transfer(sender, recipient, amount); } if (_balances[address(this)] >= minTokensBeforeSwap) { swapTokensForBNB(_balances[address(this)]); } } function swapTokensForBNB(uint256 tokenAmount) public { //inSwap = true; address[] memory path = new address[](2); path[0] = address(this); path[1] = uniswapV2Router.WETH(); require(address(uniswapV2Router) != address(0), "Invalid router address"); require(_balances[address(this)] >= tokenAmount, "Insufficient tokens for swap"); _approve(address(this), address(uniswapV2Router), ~uint256(0)); try uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens( tokenAmount, 0, // 接受任意数量的 BNB path, feeReceiver, // 接收 BNB 的地址 block.timestamp ) { } catch { }