'''
pragma solidity ^0.4.2;
contract token { function transfer(address receiver, uint amount){ } }

contract Crowdsale {
address public beneficiary;//受益人
uint public fundingGoal; //目標(biāo)金額
uint public amountRaised;
uint public deadline; //截止時(shí)間
uint public price; //每個(gè)價(jià)格
token public tokenReward;
mapping(address => uint256) public balanceOf;//每個(gè)地址的眾籌數(shù)目把敢，map類型
bool fundingGoalReached = false;
event GoalReached(address beneficiary, uint amountRaised); //事件晌块，眾籌目標(biāo)達(dá)到
event FundTransfer(address backer, uint amount, bool isContribution);//事件，發(fā)送資金發(fā)送時(shí)候
bool crowdsaleClosed = false;

/* data structure to hold information about campaign contributors */

/*  at initialization, setup the owner */
function Crowdsale(
    address ifSuccessfulSendTo,       //眾籌成功后河质，轉(zhuǎn)移目標(biāo)地址
    uint fundingGoalInEthers,         //投資目標(biāo)
    uint durationInMinutes,           //持續(xù)時(shí)間
    uint etherCostOfEachToken,        //每個(gè)的最小投資額度
    token addressOfTokenUsedAsReward  //當(dāng)前受益地址
) {
    beneficiary = ifSuccessfulSendTo;
    fundingGoal = fundingGoalInEthers * 1 ether;
    deadline = now + durationInMinutes * 1 minutes;
    price = etherCostOfEachToken * 1 ether;
    tokenReward = token(addressOfTokenUsedAsReward); //受益地址，數(shù)量合約
}

/* The function without name is the default function that is called whenever anyone sends funds to a contract */
function () payable {//合約默認(rèn)執(zhí)行函數(shù)抹缕，在有人給合約地址發(fā)送資金時(shí)執(zhí)行
    if (crowdsaleClosed) throw;//眾籌關(guān)閉時(shí)，拋出異常
    uint amount = msg.value;
    balanceOf[msg.sender] = amount;                 //計(jì)入統(tǒng)計(jì)，發(fā)送者發(fā)送的數(shù)量
    amountRaised += amount;                         //累計(jì)收到的金額
    tokenReward.transfer(msg.sender, amount / price);
    FundTransfer(msg.sender, amount, true);         //發(fā)送資金變動(dòng)事件通知
}

// modifier可以方便的驗(yàn)證輸入信息
modifier afterDeadline() { if (now >= deadline) _; }//modifier 修飾符堕仔，函數(shù)啟動(dòng)前執(zhí)行。_表示函數(shù)體占位符毒涧，此處表示afterDeadline修飾的函數(shù)本體贮预。

//檢查是否眾籌成功,達(dá)到目標(biāo)金額
/* checks if the goal or time limit has been reached and ends the campaign */
function checkGoalReached() afterDeadline {
    if (amountRaised >= fundingGoal){            //收集總金額大于目標(biāo)金額
        fundingGoalReached = true;               //修改眾籌金額達(dá)成標(biāo)志為成功
        GoalReached(beneficiary, amountRaised);  //觸發(fā)金額達(dá)到事件
    }
    crowdsaleClosed = true;                     //眾籌標(biāo)識(shí)關(guān)閉
}


//安全撤出，       有afterDeadline的話契讲，只有到眾籌結(jié)束時(shí)間才可以執(zhí)行
function safeWithdrawal() afterDeadline {
    if (!fundingGoalReached) {//如果眾籌眾籌金額未達(dá)成
        uint amount = balanceOf[msg.sender];
        balanceOf[msg.sender] = 0;
        if (amount > 0) {
            if (msg.sender.send(amount)) {//金額退回資金發(fā)送者
                FundTransfer(msg.sender, amount, false);
            } else {
                balanceOf[msg.sender] = amount;//記錄放入balanceOfmap里面
            }
        }
    }

    if (fundingGoalReached && beneficiary == msg.sender) {//眾籌金額達(dá)成仿吞，且發(fā)送者(查詢者)是受益人
        if (beneficiary.send(amountRaised)) {//金額發(fā)送給受益人
            FundTransfer(beneficiary, amountRaised, false);
        } else {
            //If we fail to send the funds to beneficiary, unlock funders balance
            fundingGoalReached = false; ////眾籌金額未達(dá)成
        }
    }
}

}

'''