ERC-20 Transfer Function – Calling Transfer Function of an ERC-20 Contract

contract-development

I want to call the transfer function of any ERC-20 contract in my Smart Contract.
I have seen that i should use "callcode" in a similar way of https://gist.github.com/critesjosh/68593429fd2f84f8f55d4ff7b74f0323.

function callcodeSetNum(address c2, uint _num) public {
if(!c2.callcode(bytes4(sha3("setNum(uint256)")), _num)) revert(); // C1's num is set
}

I could reproduce inter-contract calls to one-parameter function. However, I always get a strange error when trying to call a function with more than one parameter (as is the case of transfer).

Error: transact to TW.callSetNum errored: VM error: revert.
revert The transaction has been reverted to the initial state.
Note: The constructor should be payable if you send value. Debug the transaction to get more information.

Anyone has a clue?
Thank you

Best Answer

Perhaps you're just looking for this?

interface IERC20Token {
    function transfer(address to, uint256 amount) external returns (bool);
    // add other functions here as you want
}

contract MyContract {
    function doIt(address tokenContract, address to, uint256 amount) {
        IERC20Token(tokenContract).transfer(to, amount);
    }
}

See also https://programtheblockchain.com/posts/2018/08/02/contracts-calling-arbitrary-functions/ for when you don't know the ABI in advance (and want to just pass message data from the client).

Related Solutions

solidity – Troubleshooting VM Error: Revert with Note on Payable Functions

The problem is not with your code. The problem is the order of issuing transactions. You should follow the following steps:

Deploy MainContract
Issue createNewContract and get the returned address of the deployed SubToken Contract.

** Note that this address is the address of SubToken contract which has been deployed in createNewContract method. You need not deploy SubToken again.
Get instance of the SubToken Contract using the retrieved address in step 2.
Call the method getName1() of the instance of the SubToken Contract of step 3.

The problem was you were deploying SubToken Contract again and calling getName1(). Inside getName1() you called mc.getNameMain(address(this)); The address you were passing as parameter had not been mapped in token of MainContract. So, as there was no entry with that address, it threw error.

solidity error – Fixing Revert Error: Payable Function and Value Sent Issues

You've declared function misbehaviorJudge.

But you've implemented function misbeaviorJudge.

So the way I see it, you are trying to invoke an unimplemented function.

A couple of ways for you to avoid a similar issue next time (more precisely, convert it from a hard-to-investigate runtime problem into an easy-to-investigate compilation problem):

Option #1 - if you don't need to call function misbehaviorJudge inside contract Judge:

File IJudge.sol:

interface IJudge {
    function misbehaviorJudge(...) external returns (uint);

File Judge.sol:

import "./IJudge.sol";

contract Judge is IJudge {
    ...
}

Option #2 - if you do need to call function misbehaviorJudge inside contract Judge: