Here is my code:
pragma solidity 0.8.6;
import "./Allowance.sol";
contract SharedWallet is Allowance {
event MoneySent(address indexed _beneficiary, uint _amount);
event MoneyReceived(address indexed _from, uint _amount);
function withdrawMoney(address payable _to, uint _amount) public ownerOrAllowed(_amount) {
require(_amount <= address(this).balance, "Contract doesn't own enough money");
if(!isOwner()) {
reduceAllowance(msg.sender, _amount);
}
emit MoneySent(_to, _amount);
_to.transfer(_amount);
}
function renounceOwnership() public override onlyOwner {
revert("can't renounceOwnership here"); //not possible with this smart contract
}
fallback () external payable {
emit MoneyReceived(msg.sender, msg.value);
}
}
Are you trying to send Ether to the contract as you deploy it? As I do not think you can do that easily. Well, there is a hacky way. Ethereum contract address is deterministic, i.e. knowing the creator's address and their nonce you can calculate the future address of your smart contract. And then send ETH to that address prior to deploying the contract.
Related
pragma solidity ^0.8.7;
// SPDX-License-Identifier: MIT
contract Client {
address payable private hub;
address payable public owner;
uint256 public balance;
constructor(address payable _hub) {
hub = _hub;
owner = payable(msg.sender);
}
receive() payable external {
balance += msg.value;
}
function withdraw(address payable destAddr) public {
require(msg.sender == owner, "Only owner can withdraw funds");
uint amount = address(this).balance;
destAddr.transfer(amount);
}
function start() public payable {
require(msg.sender == owner, "Only owner can start the process");
uint amount = address(this).balance;
hub.transfer(amount);
balance = 0;
}
function setHub(address payable _new) public {
require(msg.sender == owner, "Only owner can change address");
hub = _new;
}
}
Hi i have a problem, when I deploy this contract and put as input (hub) the other contract, then send eth to this contract, i call the "start" function and throw a gas estimation error.
Someone who can help me pls...
I'm expecting that calling the start function fund will be sent to the other contract that also have a function for receiving eth
receive() payable external {
balance += msg.value;
}
You are getting that gas estimation error because your receive function on the second contract is not empty and the transaction does not have enough gas to execute the code. transfer only sends the amount of gas necessary to execute a transfer of ether (21,000 gas) and nothing more.
You can use call instead of transfer to send ether and set the amount of gas that you want to send. transfer is actually no longer recommended for sending ether.
I'm pretty new to programing in solidity and I'm currently trying to run a simple smart contract in Remix, seen bellow:
pragma solidity ^0.8.0;
import "github.com/OpenZeppelin/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol";
contract Swap {
address public owner;
uint256 public balance;
event TransferReceived(address _from, uint _amount);
event TransferSent(address _from, address _destAddr, uint _amount);
constructor() {
owner = msg.sender;
}
receive() payable external {
balance += msg.value;
emit TransferReceived(msg.sender, msg.value);
}
function withdraw(uint amount, address payable destAddr) public {
require(msg.sender == owner, "Only owner can withdraw funds");
require(amount <= balance, "Insufficient funds");
destAddr.transfer(amount);
balance -= amount;
emit TransferSent(msg.sender, destAddr, amount);
}
function transferERC20(IERC20 token, address to, uint256 amount) public {
require(msg.sender == owner, "Only owner can withdraw funds");
uint256 erc20balance = token.balanceOf(address(this));
require(amount <= erc20balance, "balance is low");
token.transfer(to, amount);
emit TransferSent(msg.sender, to, amount);
}
}
While I can successfully send BNB and call the withdraw function giving the value sent and my wallet address in the BSC testnet, I'm having issues when running the transferERC20 function. The only output that I get when calling this method is the following message:
Gas estimation errored with the following message (see below). The
transaction execution will likely fail. Do you want to force sending?
Internal JSON-RPC error. { "code": -32000, "message": "execution
reverted" }
I've tried several different addresses that I found in the testnet.bscscan website for BNB while making sure that the contract had enough funds for transfering, but I had no success.
Can someone suggest what might be going wrong in my contract/setup? Am I making this transfer properly?
fix constrcutor
constructor() {
// payable allows payment of ether with a call.
owner = payable(msg.sender);
}
make sure those require statements are satisfied
require(msg.sender == owner, "Only owner can withdraw funds");
require(amount <= balance, "Insufficient funds");
check that you are connected to correct network
I have an openZeppelin ERC721 NFT contract (MyNFTPrice.sol) and also a separate PaymentSplitter contract. My understanding is that these two contract need to be deployed separately. My question is, how do I send the price of minting from my NFT contract (MyNFTPrice.sol) to the PaymentSplitter contract? Currently, the price for minting an NFT resides in the MyNFTPrice.sol contract address.
MyNFTPrice.sol
pragma solidity ^0.8.0;
import "#openzeppelin/contracts/token/ERC721/ERC721.sol";
import "#openzeppelin/contracts/utils/Counters.sol";
import "#openzeppelin/contracts/access/Ownable.sol";
import "#openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
contract MyNFTPrice is ERC721URIStorage {
using Counters for Counters.Counter;
Counters.Counter private _tokenIds;
constructor() public ERC721("MyNFTPrice", "NFTPRICE") {}
// Mint new NFT
function mintNFT(address recipient, string memory tokenURI) public payable {
require(msg.value >= 50000000000000000, "You need 0.05 ETH to mint the NFT");
_tokenIds.increment();
uint256 newItemId = _tokenIds.current();
_mint(recipient, newItemId);
_setTokenURI(newItemId, tokenURI);
}
}
You can use the transfer() member of the address payable.
function mintNFT(address recipient, string memory tokenURI) public payable {
require(msg.value >= 50000000000000000, "You need 0.05 ETH to mint the NFT");
// effectively redirects the `msg.value` to the `0x123` address
payable(address(0x123)).transfer(msg.value);
// ... rest of your code
}
Replace the 0x123 to the real address of the PaymentSplitter.
You can also store the address in a variable and change it when you need to. In this case, it's recommended to use an authorization mechanism, such as the Ownable pattern, so that only an authorized sender can change the value.
Since the PaymentSplitter is a contract, it needs to contain the receive() or fallback() payable function. Otherwise the PaymentSplitter as the receiver would reject the incoming payment and effectively cause the whole mintNFT() transaction to revert.
contract PaymentSplitter {
receive() external payable {
// can be empty
}
}
I have a question and I try to google without much existence.
Let's take the example of this token:
1inch Token
So you can see that it has different tokens that people have sent to that address.
If I were the owner, how could I implement a function to withdraw all those tokens to my wallet?
Your contract can define the ERC20 interface function transfer(), and then execute this function on the external token contract.
pragma solidity ^0.8;
interface IERC20 {
function transfer(address _to, uint256 _amount) external returns (bool);
}
contract MyContract {
modifier onlyOwner {
require(msg.sender == address(0x123), 'Not authorized');
_;
}
function withdrawERC20Token(address _tokenContractAddress, uint256 _amount) external onlyOwner {
IERC20 token = IERC20(_tokenContractAddress);
// transfer the `_amount` of tokens (mind the decimals) from this contract address
// to the `msg.sender` - the caller of the `withdrawERC20Token()` function
bool success = token.transfer(msg.sender, _amount);
require(success, 'Could not withdraw');
}
}
I wrote the following code. I know it sends the ether from the contract balance but It doesn't allow me to send ether to the contract`s address.
How can I change the method so it will allow sending ether to the contract?
pragma solidity ^0.5.11;
contract MyFirstContract
{
function() external payable { }
function send(address payable _to, uint256 _value) public returns (bool)
{
require(_value <= address(this).balance);
_to.transfer(_value);
return true;
}
}
The reason it doesn't allow you to send ether to a contract's address could be there is no fallback function in that contract.
If you want to send ether to a contract without calling any of its functions, you need to have a fallback function in that contract to receive ether.
Add this function in the contract which you want to send ether to:
function () external payable {}
Here is a more detailed version: fallback