Erc-20
空投功能執行但餘額未更新
我為令牌生成和空投創建了以下程式碼。令牌生成正在工作。我能夠執行 Drop() 函式(並得到契約執行的確認),但代幣餘額沒有得到更新。非常感謝您的幫助
pragma solidity ^0.4.18; // ---------------------------------------------------------------------------- // '0Fucks' token contract // // Deployed to : 0xe4A96B299064aD3168dd6D503be747A59eb39c61 // Symbol : BCKE // Name : Test Token // Total supply: 100000000 // Decimals : 18 // // Enjoy. // // (c) by Moritz Neto with BokkyPooBah / Bok Consulting Pty Ltd Au 2017. The MIT Licence. // ---------------------------------------------------------------------------- // ---------------------------------------------------------------------------- // Safe maths // ---------------------------------------------------------------------------- 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; } // ---------------------------------------------------------------------------- // Owned contract // ---------------------------------------------------------------------------- contract Owned { address public owner; address public newOwner; event OwnershipTransferred(address indexed _from, address indexed _to); function Owned() public { owner = msg.sender; } modifier onlyOwner { require(msg.sender == owner); _; } function transferOwnership(address _newOwner) public onlyOwner { newOwner = _newOwner; } function acceptOwnership() public { require(msg.sender == newOwner); emit OwnershipTransferred(owner, newOwner); owner = newOwner; newOwner = address(0); } } // ---------------------------------------------------------------------------- // ERC20 Token, with the addition of symbol, name and decimals and assisted // token transfers // ---------------------------------------------------------------------------- contract BCKEToken is ERC20Interface, Owned, SafeMath { string public symbol; string public name; uint8 public decimals; uint public _totalSupply; mapping(address => uint) balances; mapping(address => mapping(address => uint)) allowed; // ------------------------------------------------------------------------ // Constructor // ------------------------------------------------------------------------ function BCKEToken() public { symbol = "BCKE"; name = "Test TokenE"; decimals = 18; _totalSupply = 100000000000000000000000000; balances[0xe4A96B299064aD3168dd6D503be747A59eb39c61] = _totalSupply; emit Transfer(address(0), 0xe4A96B299064aD3168dd6D503be747A59eb39c61, _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; } // ------------------------------------------------------------------------ // Don't accept ETH // ------------------------------------------------------------------------ function () public payable { revert(); } // ------------------------------------------------------------------------ // Owner can transfer out any accidentally sent ERC20 tokens // ------------------------------------------------------------------------ function transferAnyERC20Token(address tokenAddress, uint tokens) public onlyOwner returns (bool success) { return ERC20Interface(tokenAddress).transfer(owner, tokens); } } contract Airdrop { function drop(address addr, address[] recipients, uint256[] values) public { BCKEToken token = BCKEToken(addr); for (uint256 i = 0; i < recipients.length; i++) { token.transfer(recipients[i], values[i]); } } }
這是我在 etherwallet https://pasteboard.co/HqS8kfT.png中呼叫函式的方式
請注意空投合約有很多缺陷:
- drop 函式應該有 onlyOwner
- 修飾符令牌的合約地址不應作為參數傳遞,但應固定
0xe4A96B299064aD3168dd6D503be747A59eb39c61
是所有者的地址而不是契約的地址- 等等…
因此,如果您想將該程式碼放入主網,我建議進行非常深入的審查。
就是說,你提到的問題是平衡錯誤造成的。
這樣做:
token.transfer(recipients[i], values[i]);
您正在嘗試將 Airdrop 合約 (
0x4323383a842fcb0f7c9232B508eA6b6532bbFd83
) 擁有的代幣轉移給這些收件人。這是因為msg.sender
在代幣合約的轉賬功能中,假設的是空投合約的地址,而不是交易的原始發送者(tx.origin
)。在您的情況下,所有代幣都屬於0xe4A96B299064aD3168dd6D503be747A59eb39c61
而不屬於 Airdrop 合約。您可以將轉賬功能更改為transferFrom
並使用allowance
以允許空投移動其他賬戶擁有的代幣。