史上最全的智能合约--扣税，分红，加池子，回流，黑白名单，防机器人，增发，丢权限之分红，加池子

前面一章分享了智能合约扣税的原理，以及用什么方法实现扣税的，下面这篇文章，分享一下自动分红以为加池子的方法和注意事项。

废话不多说，先上代码。

//feihongpool这个变量是指预留在合约中的预分红的币的数量。_maxfeihong这个变量是指预留在合约的币达到什么样的数量之后分红。
if(fenhongpool>=_maxfenhong ){
  //这个例子是对所有的lp分红，那么，在fenhongpool变量之后，为什么要多乘以一个10的18次方呢，这里要特别说明一下，如果lp总的有1万个，fenhongpool是200个，那么，如果除了之后，就变成一个小于1的值了，在solidity中，不支持小数点，所以，如果不乘以一个比较大的参数，会导致分红失败，这个本人失败过几次，得出来的经验。
  uint256 tmp=fenhongpool.mul(10**18).div(ERC20(pooladdress).totalSupply());
  //分了之后，将分红池置空。然后在fenhongdetail内push当次分红的具体数量。这里特别说明一下，因为除了数据之后，肯定会有精度的问题，这个要自己心里弄清楚。fenhongdetail是一个初始化为0的数组。当每次分红之后，将每个lp分红的数额记录在这里。
  fenhongpool=0;
  fenhongdetail.push(tmp);
}
//当用户发生转帐或者加撤池子的时候，首先取出来该钱包地址，拥有的lp数量大于0，并且没有被初始化，这里用的是isinclude[sender]==false来判断的，如果是第一次，那么初始化用户开始分红的时间节点，就是将feihongdetail的长度赋值给userfeihong[sender]
if(lpvalue>0 && isinclude[sender]==false){
 //    includelp.push(sender);
      isinclude[sender]=true;
      userfeihong[sender]=feihongdetail.length-1;
  }
//当触发发分发条件，那么从用户未分红的lp开始，将用户该分的币值计算出来，并分给用户，然后userfenhong[sender]=fenhongdetail.length-1,修改用户的分红时间节点。达到合约内自动分红的目的。
if(userfenhong[sender]
   for(uint256 i=userfenhong[sender]+1;i
           tmp=fenhongdetail[i]*lpvalue;
    }
    _balances[sender]=_balances[sender].add(tmp);
    userfenhong[sender]=fenhongdetail.length-1;
 }

     function factory() external pure returns (address);
     function WETH() external pure returns (address);
 
     function addLiquidity(
         address tokenA,
         address tokenB,
         uint amountADesired,
         uint amountBDesired,
         uint amountAMin,
         uint amountBMin,
         address to,
         uint deadline
     ) external returns (uint amountA, uint amountB, uint liquidity);
     function addLiquidityETH(
         address token,
         uint amountTokenDesired,
         uint amountTokenMin,
         uint amountETHMin,
         address to,
         uint deadline
     ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
     function removeLiquidity(
         address tokenA,
         address tokenB,
         uint liquidity,
         uint amountAMin,
         uint amountBMin,
         address to,
         uint deadline
     ) external returns (uint amountA, uint amountB);
     function removeLiquidityETH(
         address token,
         uint liquidity,
         uint amountTokenMin,
         uint amountETHMin,
         address to,
         uint deadline
     ) external returns (uint amountToken, uint amountETH);
     function removeLiquidityWithPermit(
         address tokenA,
         address tokenB,
         uint liquidity,
         uint amountAMin,
         uint amountBMin,
         address to,
         uint deadline,
         bool approveMax, uint8 v, bytes32 r, bytes32 s
     ) external returns (uint amountA, uint amountB);
     function removeLiquidityETHWithPermit(
         address token,
         uint liquidity,
         uint amountTokenMin,
         uint amountETHMin,
         address to,
         uint deadline,
         bool approveMax, uint8 v, bytes32 r, bytes32 s
     ) external returns (uint amountToken, uint amountETH);
     function swapExactTokensForTokens(
         uint amountIn,
         uint amountOutMin,
         address[] calldata path,
         address to,
         uint deadline
     ) external returns (uint[] memory amounts);
     function swapTokensForExactTokens(
         uint amountOut,
         uint amountInMax,
         address[] calldata path,
         address to,
         uint deadline
     ) external returns (uint[] memory amounts);
     function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
     external
     payable
     returns (uint[] memory amounts);
     function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
     external
     returns (uint[] memory amounts);
     function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
     external
     returns (uint[] memory amounts);
     function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
     external
     payable
     returns (uint[] memory amounts);
 
     function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
     function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
     function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
     function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
     function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
 }
 
 interface IUniswapV2Router02 is IUniswapV2Router01 {
     function removeLiquidityETHSupportingFeeOnTransferTokens(
         address token,
         uint liquidity,
         uint amountTokenMin,
         uint amountETHMin,
         address to,
         uint deadline
     ) external returns (uint amountETH);
     function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
         address token,
         uint liquidity,
         uint amountTokenMin,
         uint amountETHMin,
         address to,
         uint deadline,
         bool approveMax, uint8 v, bytes32 r, bytes32 s
     ) external returns (uint amountETH);
 
     function swapExactTokensForTokensSupportingFeeOnTransferTokens(
         uint amountIn,
         uint amountOutMin,
         address[] calldata path,
         address to,
         uint deadline
     ) external;
     function swapExactETHForTokensSupportingFeeOnTransferTokens(
         uint amountOutMin,
         address[] calldata path,
         address to,
         uint deadline
     ) external payable;
     function swapExactTokensForETHSupportingFeeOnTransferTokens(
         uint amountIn,
         uint amountOutMin,
         address[] calldata path,
         address to,
         uint deadline
     ) external;
 }

        uint256 marketingTokenBalance = contractTokenBalance.div(2);
        uint256 liquidityTokenBalance = contractTokenBalance.sub(marketingTokenBalance);
        uint256 tokenBalanceToLiquifyAsBNB = liquidityTokenBalance.div(2);
        uint256 tokenBalanceToLiquify = liquidityTokenBalance.sub(tokenBalanceToLiquifyAsBNB);
        uint256 initialBalance = address(this).balance;
        uint256 tokensToSwapToBNB = tokenBalanceToLiquifyAsBNB.add(marketingTokenBalance);
        // swap tokens for BNB
        //注释见下面。
        swapTokensForEth(tokensToSwapToBNB);
       
        uint256 bnbSwapped = address(this).balance.sub(initialBalance);
        uint256 bnbToLiquify = bnbSwapped.div(3);
		//注释见下面
        addLiquidity(tokenBalanceToLiquify, bnbToLiquify);
        emit SwapAndLiquify(tokenBalanceToLiquifyAsBNB, bnbToLiquify, tokenBalanceToLiquify);
        uint256 marketingBNBToDonate = bnbSwapped.sub(bnbToLiquify);
        huiliuad.transfer(marketingBNBToDonate);
        emit DonateToMarketing(marketingBNBToDonate);
    }
    function swapTokensForEth(uint256 tokenAmount) private {
        // 初始化交易的币对。
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();
		//授权，这个授权，是将本合约或者叫本币的数量，授权给交易接口。
        _approve(address(this), address(uniswapV2Router), tokenAmount);
        // 调用接口用币兑换eth.第一个参数是兑换的数量，第二个参数是预期要兑换的数量，如果小于这个数量，则兑换失败，所以这里写0，第三个是交易的币对，第四个是兑换的eth转入的地址，第五个，限定的过期日期。
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }
	//这个是加池子函数。
    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        // approve token transfer to cover all possible scenarios
        //同样是授权，不多赘述。
        _approve(address(this), address(uniswapV2Router), tokenAmount);
        // 直接加池子。
        uniswapV2Router.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            huiliuad,
            block.timestamp
        );
    }