结构体
pragma solidity ^0.4.11; // 众筹合约 contract CrowdFunding { // 投资者 struct Funder { address addr; uint amount; } // 活动 struct Campaign { address beneficiary; uint fundingGoal; uint numFunders; uint amount; mapping (uint => Funder) funders; } uint numCampaigns; mapping (uint => Campaign) campaigns; // 新活动 function newCampaign(address beneficiary, uint goal) public returns (uint campaignID) { campaignID = numCampaigns++; // campaignID is return variable // Creates new struct and saves in storage. We leave out the mapping type. campaigns[campaignID] = Campaign(beneficiary, goal, 0, 0); } // 贡献 function contribute(uint campaignID) public payable { Campaign storage c = campaigns[campaignID]; // Creates a new temporary memory struct, initialised with the given values // and copies it over to storage. // Note that you can also use Funder(msg.sender, msg.value) to initialise. c.funders[c.numFunders++] = Funder({addr: msg.sender, amount: msg.value}); c.amount += msg.value; } // 检查目标到达 function checkGoalReached(uint campaignID) public returns (bool reached) { Campaign storage c = campaigns[campaignID]; if (c.amount < c.fundingGoal) return false; uint amount = c.amount; c.amount = 0; c.beneficiary.transfer(amount); return true; } } posted on 2018-02-28 11:44 北京涛子 阅读( ...) 评论( ...) 编辑 收藏转载于:https://www.cnblogs.com/liujitao79/p/8482794.html
