Solidity 不同代币价格答案

【问题标题】：Solidity different token priceSolidity 不同代币价格
【发布时间】：2018-01-06 03:11:14
【问题描述】：

我只是在检查我的学校项目的 Solidity 代码。我对此代码有疑问：

price = etherCostOfEachToken * 1 ether;

我可以添加类似的东西吗：

（如果他们发送超过 2 个以太币，他们将获得最多 5000 个奖励）

 If (ether contribution > 2 ether) {
    tokenReward.transfer(msg.sender, 5000);
    }else{
    tokenReward.transfer(msg.sender, amount / price);
    }

这可能吗？

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

contract Crowdsale {
    address public beneficiary;
    uint public fundingGoal; uint public amountRaised; uint public deadline; uint public price;
    token public tokenReward;
    mapping(address => uint256) public balanceOf;
    bool fundingGoalReached = false;
    event GoalReached(address beneficiary, uint amountRaised);
    event FundTransfer(address backer, uint amount, bool isContribution);
    bool crowdsaleClosed = false;

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

    /*  at initialization, setup the owner */
    function Crowdsale(
        address ifSuccessfulSendTo,
        uint fundingGoalInEthers,
        uint durationInMinutes,
        uint etherCostOfEachToken,
        token addressOfTokenUsedAsReward
    ) {
        beneficiary = ifSuccessfulSendTo;
        fundingGoal = fundingGoalInEthers * 1 ether;
        deadline = now + durationInMinutes * 1 minutes;
        price = etherCostOfEachToken * 1 ether;
        tokenReward = token(addressOfTokenUsedAsReward);
    }

    /* The function without name is the default function that is called whenever anyone sends funds to a contract */
    function () payable {
        if (crowdsaleClosed) throw;
        uint amount = msg.value;
        balanceOf[msg.sender] = amount;
        amountRaised += amount;
        tokenReward.transfer(msg.sender, amount / price);
        FundTransfer(msg.sender, amount, true);
    }

    modifier afterDeadline() { if (now >= deadline) _; }

    /* checks if the goal or time limit has been reached and ends the campaign */
    function checkGoalReached() afterDeadline {
        if (amountRaised >= fundingGoal){
            fundingGoalReached = true;
            GoalReached(beneficiary, amountRaised);
        }
        crowdsaleClosed = true;
    }


    function safeWithdrawal() afterDeadline {
        if (!fundingGoalReached) {
            uint amount = balanceOf[msg.sender];
            balanceOf[msg.sender] = 0;
            if (amount > 0) {
                if (msg.sender.send(amount)) {
                    FundTransfer(msg.sender, amount, false);
                } else {
                    balanceOf[msg.sender] = amount;
                }
            }
        }

        if (fundingGoalReached && beneficiary == msg.sender) {
            if (beneficiary.send(amountRaised)) {
                FundTransfer(beneficiary, amountRaised, false);
            } else {
                //If we fail to send the funds to beneficiary, unlock funders balance
                fundingGoalReached = false;
            }
        }
    }
}

【问题讨论】：

您觉得我下面的回答正确且有帮助吗？如果是，请标记为答案。谢谢，

标签： ethereum solidity

【解决方案1】：

是的，您可以通过将 payable 方法修改为类似：

//You can add a constant to save the bonus amount:
uint constant bonus = 5000;

//Inside this method check if amount is larger than 2:
function () payable {
    if (crowdsaleClosed) throw;
    uint amount = msg.value;
    balanceOf[msg.sender] = amount;
    amountRaised += amount;
    if (amount > 2) {
        tokenReward.transfer(msg.sender, amount / price + bonus);
    } else {
        tokenReward.transfer(msg.sender, amount / price);
    }
    tokenReward.transfer(msg.sender, amount / price);
    FundTransfer(msg.sender, amount, true);
}

【讨论】：