1. 程式人生 > >在以太坊發行代幣Token系列教程(1)

在以太坊發行代幣Token系列教程(1)

雖然國家目前嚴令禁止ICO,但是我覺得基於區塊鏈平臺的虛擬幣本身是很有價值的,大家只要不去碰基於發幣的ICO就好,因此這裡簡單談談怎麼在以太坊發行自己的代幣(Test網路)。

翻牆

目前來說,相關的網站很多都是被牆的,因此沒有梯子建議就放棄吧,推薦自己購買香港或者海外的雲伺服器,用shadowsocks搭建代理,注意如果用阿里雲的話,不要用視訊等大流量服務,可能會被封。

下載安裝

下載並安裝最新版本以太坊錢包

選擇網路

下載好以太坊錢包後選擇testnet,別選成mainnet了,建立代幣合約和轉賬代幣是要收費的。選好testnet後,錢包會去同步區塊資訊,目前都是快速同步區塊的header,而且是點對點的方式,所以很快。

選擇Rinkeby測試網路

建立賬戶

在錢包介面選擇Wallet,然後選擇ADD ACCOUNT
建立賬戶

領取測試環境的以太幣ether

新建完賬戶,餘額是0.00ether
賬號餘額

因此我們需要領取一些rinkeby測試環境的ether,進入連結,可以看到有三種方法獲取,我們就用第一種發推特的方式,點選下面圈出來的tweet的連結:
發推領取測試ether

接著會彈出以下推文,把0x0000…換成你的賬戶地址0x…,然後釋出推文即可:
發推文,替換賬戶地址
賬戶地址

接著進入twitter,找到發表的推文,拷貝連結:
拷貝推文連結

最後回到領取ether的連結,把推文連結貼上進去
獲取ether

過大概3-10分鐘,就能在你的錢包看到ether幣了!
以太幣到位

建立智慧合約

建立合約

選擇合約

拷貝以下合約程式碼(這段程式碼是從官方的token例子

pragma solidity ^0.4.16;

interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) external; }

contract TokenERC20 {
    // Public variables of the token
    string public name;
    string public symbol;
    uint8 public
decimals = 18; // 18 decimals is the strongly suggested default, avoid changing it uint256 public totalSupply; // This creates an array with all balances mapping (address => uint256) public balanceOf; mapping (address => mapping (address => uint256)) public allowance; // This generates a public event on the blockchain that will notify clients event Transfer(address indexed from, address indexed to, uint256 value); // This notifies clients about the amount burnt event Burn(address indexed from, uint256 value); /** * Constructor function * * Initializes contract with initial supply tokens to the creator of the contract */ function TokenERC20( uint256 initialSupply, string tokenName, string tokenSymbol ) public { totalSupply = initialSupply * 10 ** uint256(decimals); // Update total supply with the decimal amount balanceOf[msg.sender] = totalSupply; // Give the creator all initial tokens name = tokenName; // Set the name for display purposes symbol = tokenSymbol; // Set the symbol for display purposes } /** * Internal transfer, only can be called by this contract */ function _transfer(address _from, address _to, uint _value) internal { // Prevent transfer to 0x0 address. Use burn() instead require(_to != 0x0); // Check if the sender has enough require(balanceOf[_from] >= _value); // Check for overflows require(balanceOf[_to] + _value > balanceOf[_to]); // Save this for an assertion in the future uint previousBalances = balanceOf[_from] + balanceOf[_to]; // Subtract from the sender balanceOf[_from] -= _value; // Add the same to the recipient balanceOf[_to] += _value; emit Transfer(_from, _to, _value); // Asserts are used to use static analysis to find bugs in your code. They should never fail assert(balanceOf[_from] + balanceOf[_to] == previousBalances); } /** * Transfer tokens * * Send `_value` tokens to `_to` from your account * * @param _to The address of the recipient * @param _value the amount to send */ function transfer(address _to, uint256 _value) public { _transfer(msg.sender, _to, _value); } /** * Transfer tokens from other address * * Send `_value` tokens to `_to` on behalf of `_from` * * @param _from The address of the sender * @param _to The address of the recipient * @param _value the amount to send */ function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) { require(_value <= allowance[_from][msg.sender]); // Check allowance allowance[_from][msg.sender] -= _value; _transfer(_from, _to, _value); return true; } /** * Set allowance for other address * * Allows `_spender` to spend no more than `_value` tokens on your behalf * * @param _spender The address authorized to spend * @param _value the max amount they can spend */ function approve(address _spender, uint256 _value) public returns (bool success) { allowance[msg.sender][_spender] = _value; return true; } /** * Set allowance for other address and notify * * Allows `_spender` to spend no more than `_value` tokens on your behalf, and then ping the contract about it * * @param _spender The address authorized to spend * @param _value the max amount they can spend * @param _extraData some extra information to send to the approved contract */ function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns (bool success) { tokenRecipient spender = tokenRecipient(_spender); if (approve(_spender, _value)) { spender.receiveApproval(msg.sender, _value, this, _extraData); return true; } } /** * Destroy tokens * * Remove `_value` tokens from the system irreversibly * * @param _value the amount of money to burn */ function burn(uint256 _value) public returns (bool success) { require(balanceOf[msg.sender] >= _value); // Check if the sender has enough balanceOf[msg.sender] -= _value; // Subtract from the sender totalSupply -= _value; // Updates totalSupply emit Burn(msg.sender, _value); return true; } /** * Destroy tokens from other account * * Remove `_value` tokens from the system irreversibly on behalf of `_from`. * * @param _from the address of the sender * @param _value the amount of money to burn */ function burnFrom(address _from, uint256 _value) public returns (bool success) { require(balanceOf[_from] >= _value); // Check if the targeted balance is enough require(_value <= allowance[_from][msg.sender]); // Check allowance balanceOf[_from] -= _value; // Subtract from the targeted balance allowance[_from][msg.sender] -= _value; // Subtract from the sender's allowance totalSupply -= _value; // Update totalSupply emit Burn(_from, _value); return true; } }

合約資訊

token name ,和 token symbol自己可以隨便命名,然後把費用Fee拉到最大(Faster,為了更快的讓礦工記錄你的合約),最後點擊發布就ok了。

發起轉賬

目標賬戶地址可以填寫[0x8DF451466Ee0e75F73eafB36a8C0833F3022a687](/send/0x8DF451466Ee0e75F73eafB36a8C0833F3022a687 "0x8DF451466Ee0e75F73eafB36a8C0833F3022a687")

轉賬介面

檢視轉賬資訊
image.png

點選其中一筆轉賬
image.png

點選上圖的Transaction下的藍色地址,可以前往rinkeby.io檢視詳細資訊

小結

發代幣的基本方法已經介紹完了,在後續章節,會繼續介紹發行代幣的高階技巧,歡迎大家訂閱。
這裡要額外提一下,發代幣的關鍵就是智慧合約,而智慧合約一旦上傳是不可變的,因此請務必小心謹慎:
- 確保智慧合約沒有Bug,一旦存在Bug,你就別想去修復了
- 程式碼要儘量簡潔,程式碼越長,執行費用越高(每次轉賬都要執行一次)

同時,大家也可以在這裡檢視代幣的Coin