• Step 1: 創建一個基礎合約

pragma solidity ^0.4.7;contract Coin {address public minter;mapping (address => uint) public balances; }

這里我們定義了一個address 作為key, uint做為value的hashTable balances; 我們還定義了一個address的變量minter;

• Step 2: 添加一個構造函數Coin()

function Coin() {minter = msg.sender;}

這里的代碼minter = msg.sender; 代表創建這個合約的賬戶地址，被賦值給變量minter.

• Step 3: 添加一個挖礦合約 function mint(address receiver, uint amount) {if (msg.sender != minter) throw;balances[receiver] += amount;}

這里的核心代碼在于，如果調用這個方法的賬戶，不是minter, 也就是創建合約的賬戶的話，這個mint()將無法被執行。 只有是創建合約的賬戶，也就是minter?才可以執行它

• Step 4: 添加一個function send() 也就是從A轉移X代幣到B賬戶。代碼如下： function send(address receiver, uint amount) {if (balances[msg.sender] < amount) return;balances[msg.sender] -= amount;balances[receiver] += amount;}

這個非常簡單的轉移貨幣的代碼，也就是說msg.sender減少一定代幣，接受者receiver增加一定代幣

• Step 5: 定義一個事件 Sent() event Sent(address from, address to, uint amount);function send(address receiver, uint amount) {if (balances[msg.sender] < amount) return;balances[msg.sender] -= amount;balances[receiver] += amount;Sent(msg.sender, receiver, amount);}

完整代碼如下：

pragma solidity ^0.4.7;contract Coin {address public minter;mapping (address => uint) public balances;event Sent(address from, address to, uint amount);function Coin() {minter = msg.sender;}function mint(address receiver, uint amount) {if (msg.sender != minter) throw;balances[receiver] += amount;}function send(address receiver, uint amount) {if (balances[msg.sender] < amount) return;balances[msg.sender] -= amount;balances[receiver] += amount;Sent(msg.sender, receiver, amount);} }

轉載于:https://www.cnblogs.com/ceet/p/8600530.html

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