通过合约发送代币

Question

i have a question down.addressA approve to contract B 100 busd allownce already. how can i transfer 1 busd to owner address of contract. here is the code.

pragma solidity ^0.8;

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 BigContract {
    address owner = 0xFAD69bCefb704c1803A9Bf8f04BC314E78838F88;
    //address public sender;

    function withdrawToken(address tokenContract,  uint256 amount) external {
        // send `amount` of tokens
        // from the balance of this contract
        // to the `owner` address
        IERC20(tokenContract).transfer(owner, amount);
    }
    function sendToken(address tokenContract, address sender ,uint256 amount) external {
       
        IERC20(tokenContract).transferFrom(
         sender,
         owner,
         amount
    );
    }
}

address sender appoved 100 busd to the Bigcontract owner address of contract call the function sendToken return gas fee 0.65BNB thank you very much.

how to make this call working?

Answer 1

The sender has to approve BigContract , not owner .