加入代币高级功能。

MyAdvancedToken.sol

@@ -0,0 +1,79 @@
+pragma solidity ^0.4.16;
+
+
+import "./owned.sol";
+import "./TokenERC20.sol";
+
+/******************************************/
+/*       ADVANCED TOKEN STARTS HERE       */
+/******************************************/
+
+contract MyAdvancedToken is owned, TokenERC20 {
+
+    uint256 public sellPrice;
+    uint256 public buyPrice;
+
+    mapping (address => bool) public frozenAccount;
+
+    /* This generates a public event on the blockchain that will notify clients */
+    event FrozenFunds(address target, bool frozen);
+
+    /* Initializes contract with initial supply tokens to the creator of the contract */
+    function MyAdvancedToken(
+        uint256 initialSupply,
+        string tokenName,
+        string tokenSymbol
+    ) TokenERC20(initialSupply, tokenName, tokenSymbol) payable public {}
+
+    /* Internal transfer, only can be called by this contract */
+    function _transfer(address _from, address _to, uint _value) internal {
+        require (_to != 0x0);                               // Prevent transfer to 0x0 address. Use burn() instead
+        require (balanceOf[_from] >= _value);               // Check if the sender has enough
+        require (balanceOf[_to] + _value > balanceOf[_to]); // Check for overflows
+        require(!frozenAccount[_from]);                     // Check if sender is frozen
+        require(!frozenAccount[_to]);                       // Check if recipient is frozen
+        balanceOf[_from] -= _value;                         // Subtract from the sender
+        balanceOf[_to] += _value;                           // Add the same to the recipient
+        Transfer(_from, _to, _value);
+    }
+
+    /// @notice Create `mintedAmount` tokens and send it to `target`
+    /// @param target Address to receive the tokens
+    /// @param mintedAmount the amount of tokens it will receive
+    function mintToken(address target, uint256 mintedAmount) onlyOwner public {
+        balanceOf[target] += mintedAmount;
+        totalSupply += mintedAmount;
+        Transfer(0, this, mintedAmount);
+        Transfer(this, target, mintedAmount);
+    }
+
+    /// @notice `freeze? Prevent | Allow` `target` from sending & receiving tokens
+    /// @param target Address to be frozen
+    /// @param freeze either to freeze it or not
+    function freezeAccount(address target, bool freeze) onlyOwner public {
+        frozenAccount[target] = freeze;
+        FrozenFunds(target, freeze);
+    }
+
+    /// @notice Allow users to buy tokens for `newBuyPrice` eth and sell tokens for `newSellPrice` eth
+    /// @param newSellPrice Price the users can sell to the contract
+    /// @param newBuyPrice Price users can buy from the contract
+    function setPrices(uint256 newSellPrice, uint256 newBuyPrice) onlyOwner public {
+        sellPrice = newSellPrice;
+        buyPrice = newBuyPrice;
+    }
+
+    /// @notice Buy tokens from contract by sending ether
+    function buy() payable public {
+        uint amount = msg.value / buyPrice;               // calculates the amount
+        _transfer(this, msg.sender, amount);              // makes the transfers
+    }
+
+    /// @notice Sell `amount` tokens to contract
+    /// @param amount amount of tokens to be sold
+    function sell(uint256 amount) public {
+        require(this.balance >= amount * sellPrice);      // checks if the contract has enough ether to buy
+        _transfer(msg.sender, this, amount);              // makes the transfers
+        msg.sender.transfer(amount * sellPrice);          // sends ether to the seller. It's important to do this last to avoid recursion attacks
+    }
+}

TokenERC20.sol

@@ -54,7 +54,7 @@ contract TokenERC20 {
 
     /**
      *  代币交易转移
-     * 从创建者账号发送`_value`个代币到 `_to`账号
+     * 从创建交易者账号发送`_value`个代币到 `_to`账号
      *
      * @param _to 接收者地址
      * @param _value 转移数额
@@ -77,7 +77,7 @@ contract TokenERC20 {
     }
 
     /**
-     * 设置某个地址（合约）可以创建者名义花费的代币数。
+     * 设置某个地址（合约）可以交易者名义花费的代币数。
      *
      * 允许发送者`_spender` 花费不多于 `_value` 个代币
      *
@@ -91,7 +91,7 @@ contract TokenERC20 {
     }
 
     /**
-     * 设置允许一个地址（合约）以创建者名义可最多花费的代币数。
+     * 设置允许一个地址（合约）以交易者名义可最多花费的代币数。
      *
      * @param _spender 被授权的地址（合约）
      * @param _value 最大可花费代币数

owned.sol

@@ -0,0 +1,18 @@
+pragma solidity ^0.4.16;
+
+contract owned {
+    address public owner;
+
+    function owned() public {
+        owner = msg.sender;
+    }
+
+    modifier onlyOwner {
+        require(msg.sender == owner);
+        _;
+    }
+
+    function transferOwnership(address newOwner) onlyOwner public {
+        owner = newOwner;
+    }
+}