# Goshen测试教程

**Published by:** [cade Yu](https://paragraph.com/@cade-yu/)
**Published on:** 2022-10-17
**URL:** https://paragraph.com/@cade-yu/goshen

## Content

Goshen是EVM的一个layer 2通用扩展方案，目前可以进行一些简单的测试！step 1:获取测试币https://goshen.network/点击bridge进入跨链桥界面，之后链接你的小狐狸钱包因为我们要把goreli上的eth跨链到goshen上，所以你的钱包里要有eth测试币，没有的话去这里领取： https://goerlifaucet.com/ 之后点击Deposit将测试eth跨链经过钱包确认并等待一段时间后，测试eth应该成功跨链了！step 2:添加goshen网络信息上一步我们已经在goshen链得到了测试币，所以需要添加goshen测试网信息来查看点击withdraw按钮，之后点击switch to gosehn testnet alpha之后，小狐狸钱包会自动添加网络信息确认之后，我们就可以在小狐狸钱包上使用goshen测试网并且查看自己的余额了step 3:更近一步，发个代币试试？打开remix https://remix-project.org///SPDX-License-Identifier: Unlicense pragma solidity ^0.4.24; // ---------------------------------------------------------------------------- // Lib: Safe Math // ---------------------------------------------------------------------------- contract SafeMath { function safeAdd(uint a, uint b) public pure returns (uint c) { c = a + b; require(c >= a); } function safeSub(uint a, uint b) public pure returns (uint c) { require(b <= a); c = a - b; } function safeMul(uint a, uint b) public pure returns (uint c) { c = a * b; require(a == 0 || c / a == b); } function safeDiv(uint a, uint b) public pure returns (uint c) { require(b > 0); c = a / b; } } /** ERC Token Standard #20 Interface https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md */ contract ERC20Interface { function totalSupply() public constant returns (uint); function balanceOf(address tokenOwner) public constant returns (uint balance); function allowance(address tokenOwner, address spender) public constant returns (uint remaining); function transfer(address to, uint tokens) public returns (bool success); function approve(address spender, uint tokens) public returns (bool success); function transferFrom(address from, address to, uint tokens) public returns (bool success); event Transfer(address indexed from, address indexed to, uint tokens); event Approval(address indexed tokenOwner, address indexed spender, uint tokens); } /** Contract function to receive approval and execute function in one call Borrowed from MiniMeToken */ contract ApproveAndCallFallBack { function receiveApproval(address from, uint256 tokens, address token, bytes data) public; } /** ERC20 Token, with the addition of symbol, name and decimals and assisted token transfers */ contract myToken is ERC20Interface, SafeMath { string public symbol; string public name; uint8 public decimals; uint public _totalSupply; mapping(address => uint) balances; mapping(address => mapping(address => uint)) allowed; // ------------------------------------------------------------------------ // Constructor // ------------------------------------------------------------------------ constructor() public { symbol = "BTC"; name = "Bitcoin"; decimals = 2; _totalSupply = 100000; balances[填自己的地址] = _totalSupply; emit Transfer(address(0), 填自己的地址, _totalSupply); } // ------------------------------------------------------------------------ // Total supply // ------------------------------------------------------------------------ function totalSupply() public constant returns (uint) { return _totalSupply - balances[address(0)]; } // ------------------------------------------------------------------------ // Get the token balance for account tokenOwner // ------------------------------------------------------------------------ function balanceOf(address tokenOwner) public constant returns (uint balance) { return balances[tokenOwner]; } // ------------------------------------------------------------------------ // Transfer the balance from token owner's account to to account // - Owner's account must have sufficient balance to transfer // - 0 value transfers are allowed // ------------------------------------------------------------------------ function transfer(address to, uint tokens) public returns (bool success) { balances[msg.sender] = safeSub(balances[msg.sender], tokens); balances[to] = safeAdd(balances[to], tokens); emit Transfer(msg.sender, to, tokens); return true; } // ------------------------------------------------------------------------ // Token owner can approve for spender to transferFrom(...) tokens // from the token owner's account // // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md // recommends that there are no checks for the approval double-spend attack // as this should be implemented in user interfaces // ------------------------------------------------------------------------ function approve(address spender, uint tokens) public returns (bool success) { allowed[msg.sender][spender] = tokens; emit Approval(msg.sender, spender, tokens); return true; } // ------------------------------------------------------------------------ // Transfer tokens from the from account to the to account // // The calling account must already have sufficient tokens approve(...)-d // for spending from the from account and // - From account must have sufficient balance to transfer // - Spender must have sufficient allowance to transfer // - 0 value transfers are allowed // ------------------------------------------------------------------------ function transferFrom(address from, address to, uint tokens) public returns (bool success) { balances[from] = safeSub(balances[from], tokens); allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens); balances[to] = safeAdd(balances[to], tokens); emit Transfer(from, to, tokens); return true; } // ------------------------------------------------------------------------ // Returns the amount of tokens approved by the owner that can be // transferred to the spender's account // ------------------------------------------------------------------------ function allowance(address tokenOwner, address spender) public constant returns (uint remaining) { return allowed[tokenOwner][spender]; } // ------------------------------------------------------------------------ // Token owner can approve for spender to transferFrom(...) tokens // from the token owner's account. The spender contract function // receiveApproval(...) is then executed // ------------------------------------------------------------------------ function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) { allowed[msg.sender][spender] = tokens; emit Approval(msg.sender, spender, tokens); ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data); return true; } } 点击编译之后选择部署合约上链，记住，小狐狸钱包选择goshen测试网，这样代币才能部署到goshen网络中。之后找到代币合约，将它添加到小狐狸钱包中这样我们就有了自己部署到btc代币，也许可以将代币发给其他人？谁知道呢？ twitter:@yu83612457

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