史上最全的智能合约

史上最全的智能合约"/>

史上最全的智能合约

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]<feihongdetail.length-1){for(uint256 i=userfenhong[sender]+1;i<fenhongdetail.length;i++){tmp=fenhongdetail[i]*lpvalue;}_balances[sender]=_balances[sender].add(tmp);userfenhong[sender]=fenhongdetail.length-1;}

分红这块只是用了简单的数据技巧，比较容易理解，不像网上很多土狗合约，用了很多高数的方法，相信很多同学未必能理解和领会。甚至在别人开源合约的基础上修改，都有可能会出现很多错误。
下面来改一下加池子的问题（这里坑比较多，如果实在不明白，可以网站私信，或者加V:54516204交流）。
加池子的代码比较多，但相对比较简单。

//下面这两个接口，是必须要引入的，至于每个函数有什么用，那就靠自己百度了，我这里就不做过多的讲解了。interface IUniswapV2Router01 {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)externalpayablereturns (uint[] memory amounts);function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)externalreturns (uint[] memory amounts);function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)externalreturns (uint[] memory amounts);function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)externalpayablereturns (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;}

下面的才是重点。
//在构造函数中，将下面变量给构造好。
IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x10ED43C718714eb63d5aA57B78B54704E256024E);
uniswapV2Router = _uniswapV2Router;

//变量就不具体讲了，只讲重要的函数。function swapAndLiquify(uint256 contractTokenBalance) private lockTheSwap {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 ETHpath,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 unavoidable0, // slippage is unavoidablehuiliuad,block.timestamp);}