坚固性:我们不能抽离

Question

我可以通过WETH智能合同将ETH转换为WETH，并将其存入我的智能合同地址，但当我想通过WETH智能契约将WETH转换为ETH并将其提取到我的钱包地址时，我无法做到。

pragma solidity ^0.5.0;
interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint256 value) external payable;

}

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract testwithdraw {
    uint256 public ETHAnt;
    address public WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;  

    function deposit() public payable{
        ETHAnt = msg.value;      
        IWETH(WETH).deposit.value(ETHAnt)();
    }

    function getContractBalance(address _to) public view returns(uint) {
       uint256 Balance = IERC20(WETH).balanceOf(_to);
       return Balance;
    }

    function withdraw(uint256 _value) public payable { 
        IWETH(WETH).withdraw.value(_value);
    }
}

当使用提取函数时，它告诉我它成功地运行了。但我发现日志中的from实际上是我的钱包地址，to是我的智能契约地址。这里发生了什么事？

status  true Transaction mined and execution succeed
transaction hash    0x2859b5188b12cb2f0849a26777a5d2d0972e0e2ce000b548b80f3e5ae3b85b32
from    0xAb2942DEcDEa92A43d84DE7097a2e8df373e41Ab
to  testwithdraw.withdraw(uint256) 0xa5f43d3A0C3ee2A99511A14698F0DB082491C751
gas 22323 gas
transaction cost    22323 gas 
hash    0x2859b5188b12cb2f0849a26777a5d2d0972e0e2ce000b548b80f3e5ae3b85b32
input   0x2e1...00000
decoded input   {
    "uint256 _value": "1000000000000000000000"
}
decoded output   - 
logs    []
val 0 wei

Answer 1

当您使用IWETH( WETH ).withdraw.value(_value)退出ETH时，它会从WETH合同中撤回ETH并将它们存储在您的合同上。为了能够提取收到的资金，您需要在取款功能中添加类似payable(msg.sender).transfer(address(this).balance)的内容。