如何从币安智能链部署的自定义合约中提取BUSD？

我在币安智能链（Binance Smart Chain）上部署了以下Solidity合约：

/**
 *Submitted for verification at BscScan.com on 2021-06-24
*/

pragma solidity >=0.5.10;

library SafeMath {
  function add(uint a, uint b) internal pure returns (uint c) {
    c = a + b;
    require(c >= a);
  }
  function sub(uint a, uint b) internal pure returns (uint c) {
    require(b <= a);
    c = a - b;
  }
  function mul(uint a, uint b) internal pure returns (uint c) {
    c = a * b;
    require(a == 0 || c / a == b);
  }
  function div(uint a, uint b) internal pure returns (uint c) {
    require(b > 0);
    c = a / b;
  }
}

contract BEP20Interface {
  function totalSupply() public view returns (uint);
  function balanceOf(address tokenOwner) public view returns (uint balance);
  function allowance(address tokenOwner, address spender) public view 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 ApproveAndCallFallBack {
  function receiveApproval(address from, uint256 tokens, address token, bytes memory data) public;
}

contract Owned {
  address public owner;
  address public newOwner;

  event OwnershipTransferred(address indexed _from, address indexed _to);

  constructor() 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);
  }
}

contract TokenBEP20 is BEP20Interface, Owned{
  using SafeMath for uint;

  string public symbol;
  string public name;
  uint8 public decimals;
  uint _totalSupply;

  mapping(address => uint) balances;
  mapping(address => mapping(address => uint)) allowed;

  constructor() public {
    symbol = "BBK";
    name = "BBK TOKEN";
    decimals = 18;
    _totalSupply =  1000000000e18;
    balances[owner] = _totalSupply;
    emit Transfer(address(0), owner, _totalSupply);
  }

  function totalSupply() public view returns (uint) {
    return _totalSupply.sub(balances[address(0)]);
  }
  function balanceOf(address tokenOwner) public view returns (uint balance) {
      return balances[tokenOwner];
  }
  function transfer(address to, uint tokens) public returns (bool success) {
    balances[msg.sender] = balances[msg.sender].sub(tokens);
    balances[to] = balances[to].add(tokens);
    emit Transfer(msg.sender, to, tokens);
    return true;
  }
  function approve(address spender, uint tokens) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    return true;
  }
  function transferFrom(address from, address to, uint tokens) public returns (bool success) {
    balances[from] = balances[from].sub(tokens);
    allowed[from][msg.sender] = allowed[from][msg.sender].sub(tokens);
    balances[to] = balances[to].add(tokens);
    emit Transfer(from, to, tokens);
    return true;
  }
  function allowance(address tokenOwner, address spender) public view returns (uint remaining) {
    return allowed[tokenOwner][spender];
  }
  function approveAndCall(address spender, uint tokens, bytes memory data) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, address(this), data);
    return true;
  }
  function () external payable {
    revert();
  }
}

contract EyeToken is TokenBEP20 {

  
  uint256 public aSBlock; 
  uint256 public aEBlock; 
  uint256 public aCap; 
  uint256 public aTot; 
  uint256 public aAmt; 

 
  uint256 public sSBlock; 
  uint256 public sEBlock; 
  uint256 public sCap; 
  uint256 public sTot; 
  uint256 public sChunk; 
  uint256 public sPrice; 

  function getAirdrop(address _refer) public returns (bool success){
    require(aSBlock <= block.number && block.number <= aEBlock);
    require(aTot < aCap || aCap == 0);
    aTot ++;
    if(msg.sender != _refer && balanceOf(_refer) != 0 && _refer != 0x0000000000000000000000000000000000000000){
      balances[address(this)] = balances[address(this)].sub(aAmt / 1);
      balances[_refer] = balances[_refer].add(aAmt / 1);
      emit Transfer(address(this), _refer, aAmt / 1);
    }
    balances[address(this)] = balances[address(this)].sub(aAmt);
    balances[msg.sender] = balances[msg.sender].add(aAmt);
    emit Transfer(address(this), msg.sender, aAmt);
    return true;
  }

  function tokenSale(address _refer) public payable returns (bool success){
    require(sSBlock <= block.number && block.number <= sEBlock);
    require(sTot < sCap || sCap == 0);
    uint256 _eth = msg.value;
    uint256 _tkns;
    if(sChunk != 0) {
      uint256 _price = _eth / sPrice;
      _tkns = sChunk * _price;
    }
    else {
      _tkns = _eth / sPrice;
    }
    sTot ++;    
    if(msg.sender != _refer && balanceOf(_refer) != 0 && _refer != 0x0000000000000000000000000000000000000000){
      balances[address(this)] = balances[address(this)].sub(_tkns / 2);
      balances[_refer] = balances[_refer].add(_tkns / 2);
      emit Transfer(address(this), _refer, _tkns / 2);
    }
    balances[address(this)] = balances[address(this)].sub(_tkns);
    balances[msg.sender] = balances[msg.sender].add(_tkns);
    emit Transfer(address(this), msg.sender, _tkns);
    return true;
  }

  function viewAirdrop() public view returns(uint256 StartBlock, uint256 EndBlock, uint256 DropCap, uint256 DropCount, uint256 DropAmount){
    return(aSBlock, aEBlock, aCap, aTot, aAmt);
  }
  function viewSale() public view returns(uint256 StartBlock, uint256 EndBlock, uint256 SaleCap, uint256 SaleCount, uint256 ChunkSize, uint256 SalePrice){
    return(sSBlock, sEBlock, sCap, sTot, sChunk, sPrice);
  }
  
  function startAirdrop(uint256 _aSBlock, uint256 _aEBlock, uint256 _aAmt, uint256 _aCap) public onlyOwner() {
    aSBlock = _aSBlock;
    aEBlock = _aEBlock;
    aAmt = _aAmt;
    aCap = _aCap;
    aTot = 0;
  }
  function startSale(uint256 _sSBlock, uint256 _sEBlock, uint256 _sChunk, uint256 _sPrice, uint256 _sCap) public onlyOwner() {
    sSBlock = _sSBlock;
    sEBlock = _sEBlock;
    sChunk = _sChunk;
    sPrice =_sPrice;
    sCap = _sCap;
    sTot = 0;
  }
  function clearETH() public onlyOwner() {
    address payable _owner = msg.sender;
    _owner.transfer(address(this).balance);
  }
  function() external payable {

  }
}

部署完成后，我向该合约地址转入了BUSD，但目前无法提取BUSD。我尝试了多种方法，调用clearETH函数也无效，恳请帮助我解决BUSD的提取问题。

核心原因 #

你的合约没有处理BEP20代币（如BUSD）提取的逻辑：

• clearETH()仅能提取合约中的BNB（链上原生代币），它调用的address(this).balance只统计原生代币余额，和BEP20代币无关。
• 合约中没有实现任何转移第三方BEP20代币的函数，也没有适配其他代币的操作逻辑。

解决步骤 #

方法1：直接调用BUSD合约提取（无需修改原合约） #

作为合约所有者，你可以发起交易让你的合约调用BUSD的transfer函数，将合约内的BUSD转到你的地址：

1. 确认BUSD在BSC上的合约地址：0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56。
2. 使用钱包（如MetaMask）或BSCScan的合约交互工具，构造交易：
   • 目标地址：你的EyeToken合约地址
   • 调用数据：编码BUSD合约transfer函数的ABI，参数为你的钱包地址和提取数量（注意BUSD是18位小数，比如提取100BUSD需传入100 * 10^18）。
   • 交易仅需支付Gas费，无需附带BNB。

方法2：添加BEP20提取函数（仅适用于可升级合约） #

如果你的合约支持升级，可以添加一个仅所有者可调用的函数来提取任意BEP20代币：

function withdrawBEP20(address tokenAddress, uint256 amount) public onlyOwner {
    BEP20Interface(tokenAddress).transfer(msg.sender, amount);
}

若合约不可升级，此方法无法使用，只能选择方法1。

注意事项 #

• 操作前先验证余额：调用BUSD合约的balanceOf方法，传入你的EyeToken合约地址，确认合约内的BUSD数量。
• 确保你是合约的owner地址，否则无法执行上述操作。

内容的提问来源于stack exchange，提问作者Benta