CODEWITHSUNDEEP
ethereumsolidity
jumar
jumar

Reputation: 309

Why can't I use this transferEther function to send Ether to the smart contract?

I have this code I have entered into Remix IDE, as ReceivedEther.sol, a standalone smart contract.

I've transferred 0.02 Ether to the smart contract, using MetaMask.

When I checked the smart contract's balance, it returns 200000000000000000, as expected.

If I try to use the transferEther function, however, and enter a number smaller than this - say, 0.005 ETH, or 50000000000000000 as the amount - it doesn't work using MetaMask.

When MetaMask prompts me it's never for that amount. It's for 0 ETH and 0.00322 gas fee (or whatever the gas is). Basically it always set the amount of ETH at 0 and only charges the fee.

Why can't I transfer an amount of ETH using this function in the Remix IDE with MetaMask?

pragma solidity ^0.8.0;


contract ReceivedEther {

    function transferEther(address payable _recipient, uint _amount) external returns (bool) {
        require(address(this).balance >= _amount, 'Not enough Ether in contract!');
        _recipient.transfer(_amount);
        return true;
    }
    
    /**
    * @return contract balance
    */
    function contractBalance() external view returns (uint) {
        return address(this).balance;
    }
}

Upvotes: 0

Views: 1477

Answers (1)

Petr Hejda
Petr Hejda

Reputation: 43481

Your code sends ETH (stated in the _amount variable) from the smart contract to the _recipient. So it doesn't require any ETH to be sent in order to execute the transferEther() function.

If you want your contract to accept ETH, the function that accepts it (or the general fallback() or receive() function) needs to be marked as payable.

Example:

pragma solidity ^0.8.0;

contract ReceivedEther {

    receive() external payable {} // note the `payable` keyword

    // rest of your implementation
}

Then you can send whathever amount of ETH to the smart contract address (without specifying any function to execute).

See more at https://docs.soliditylang.org/en/v0.8.5/contracts.html#receive-ether-function

If you want to prefill the amount in MetaMask from Remix IDE, you can use the "Value" input in the "Deploy & Run Transactions" tab.

Upvotes: 4

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