Solidity ERC20 代币 ERC20InsufficientAllowance 在 Transferfrom 函数上出现错误

Question

我一直在尝试在 Remix 上开发自己的 ERC20 代币作为试验。 我使用树帐户作为令牌。 第一个（0x5B38Da6a701c568545dCfcB03FcB875f56beddC4）是合约所有者，第二个（0xAb8483F64d9C6d1EcF9b849Ae677dD3315835cb2）是批准从合约所有者的帐户发送代币的帐户，第三个（0x4B20993Bc481） 177ec7E8f571ceCaE8A9e22C02db) 是接收器。

当我运行transferfrom函数时，我收到“ERC20InsufficientAllowance”错误。津贴功能正常工作，显示津贴金额。

批准功能有效。在我批准代币委托后，我可以验证它。

    function approve(address spender, uint256 value) public checkPaused returns (bool) {
        if (spender == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        
        _approve(msg.sender, spender, value);

        return true;
    }

    function _approve(address owner, address spender, uint256 value) internal {
        _allowances[owner][spender] = value;

        emit Approve(owner, spender, value);
    }

getAllowance 函数也可以工作。

    function getAllowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }

当我运行transferfrom函数时，我收到ERC20InsufficientAllowance错误。我不明白为什么。

   function transferFrom(address from, address to, uint256 value) public checkPaused returns (bool) {
        if (from == address(0) || to == address(0)) {
            revert ERC20InvalidSender(address(0));
        }

        if (_balances[from] < value) {
            revert ERC20InsufficientBalance(msg.sender, _balances[from], value);
        }

        if (_allowances[from][to] < value) {
            revert ERC20InsufficientAllowance(to, _allowances[from][to], value); //error
        }

        _spendAllowance(from, to, value);

        _transfer(from, to, value);

        return true;
    }

    function _transfer(address from, address to, uint256 value) internal {
        _balances[from] -= value;
        _balances[to] += value;

        emit Transfer(from, to, value);
    }

    function _spendAllowance(address owner, address spender, uint256 value) internal {
        _allowances[owner][spender] -= value;

        emit SpendAllowance(owner, spender, _allowances[owner][spender] - value);
    }

ERC20配额不足

[vm]from: 0xAb8...35cb2to: ShivaToken.transferFrom(address,address,uint256) 0x80d...4BB9Bvalue: 0 weidata: 0x23b...003e8logs: 0hash: 0xd05...7a5d7
status  0x0 Transaction mined but execution failed
transaction hash    0xd0561c9e4f2195c3ab545a29e02f747ad54e28aae092ddd92a6923d49107a5d7
block hash  0x57c90613d4e65424402b0f96f97d671783bf024333cf48315f0b7b9e66082dda
block number    586
from    0xAb8483F64d9C6d1EcF9b849Ae677dD3315835cb2
to  ShivaToken.transferFrom(address,address,uint256) 0x80d527dF27B22d91E1AC56868e7AA5e7Ebf4BB9B
gas 3000000 gas
transaction cost    30318 gas 
execution cost  8366 gas 
input   0x23b...003e8
output  0xfb8f41b20000000000000000000000004b20993bc481177ec7e8f571cecae8a9e22c02db000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003e8
decoded input   {
    "address from": "0x5B38Da6a701c568545dCfcB03FcB875f56beddC4",
    "address to": "0x4B20993Bc481177ec7E8f571ceCaE8A9e22C02db",
    "uint256 value": "1000"
}
decoded output  {
    "0": "bool: true"
}
logs    []
raw logs    []
transact to ShivaToken.transferFrom errored: Error occurred: revert.

revert
    The transaction has been reverted to the initial state.
Error provided by the contract:
ERC20InsufficientAllowance
Parameters:
{
 "spender": {
  "value": "0x4B20993Bc481177ec7E8f571ceCaE8A9e22C02db",
  "documentation": "Address that may be allowed to operate on tokens without being their owner."
 },
 "allowance": {
  "value": "0",
  "documentation": "Amount of tokens a `spender` is allowed to operate with."
 },
 "needed": {
  "value": "1000",
  "documentation": "Minimum amount required to perform a transfer."
 }
}
If the transaction failed for not having enough gas, try increasing the gas limit gently.

Answer 1

        if (_allowances[from][to] < value) {
            revert ERC20InsufficientAllowance(to, _allowances[from][to], value); //error
        }

        _spendAllowance(from, to, value);

这里您使用

to

作为支出者，但支出者实际上是

msg.sender

。