playing aroung with payable following a course tutorial, it's working fine for the instructor but me for me it's throwing away an error. I'm trying to execute a function to send ether to the actual deployed contract.
You should first convert to address and then to payable
payable(address(this)).transfer(msg.value);
also this code doesn't have much sense since you are transferring to the contract the same ether amount the contract is already receiving, you can just leave the function in blank if you only want to receive the ether or use some receive function
Related
when I try to run the pickWinner function of my lottery contract, I get such an error. With getPlayers, I can add players and query with players. The address of the manager is visible, but I cannot run the pickWinner function by selecting the address of the manager. What could be the reason?
I did try different values but i did not find solution
You need to post the code so we can figure out the answer, but I can see your pickWinner function has a restricted modifier. If the modifier is preventing the transaction from executing, then the client (remix, metamask, etc) won't be able to estimate the gas.
I am trying to deploy this contract
https://github.com/juustesout/EtherRanger/blob/main/EtherRanger.sol
to BSC Testnet, and I get this error in return :
"revert
The transaction has been reverted to the initial state.
Note: The called function should be payable if you send value and the value you send should be less than your current balance.
Debug the transaction to get more information. "
this is an example of a failed transaction on BSC Testnet
https://testnet.bscscan.com/tx/0x5cbe0adcf6a522d89c974cadf70358dd9d79476988b4fb829fc1cc86c88aff0c
I tried forking multiple contracts from BSC, working tokens, but I always get the same error. I tried adding 'payable' to the constructor function, as other StackOverflow posts suggest, but no go. I have been reading any number of posts through Google Search, but I am getting nowhere.
The contracts compile flawless, no errors, no warnings, but they just won't deploy.
Could someone check if they can deploy this contract on BSC Testnet ? It may be a setting on my Remix or something, I am at a loss, I cannot tell where the error comes from.
I don’t know anything about this contract but I guess the hardcoded addresses for the IBEP20 and others are the problem. You need to deploy these contracts too and then pass their addresses to the interface addresses in your constructor.
But to connect to the BSC test network, you need to find the drop-down menu with a list of networks at the top of the MetaMask
https://domhtml.ru/en/sozdanie-sobstvennyh-tokenov-standarta-bep-20-v-seti-binance-smart-chain-bsc-pri-pomoshhi-remix-ide/
Contract address is
https://polygonscan.com/address/0x6eef14237fdc122a70651b11560cffb2fe57ca1a#writeContract
whatever i do i get an error at transfer rewards and it's driving me crazy
My contract needs LINK token in order to function.
I want to let users fund LINK tokens to the contract via a function on the contract, and then do some logic for the user based on their funding.
How can i make this possible within the contract?
I've tried to do calls like this.
LINK.balanceOf(walletaddress) does work, (It gets the link amount that's in the wallet).
However, this function below does not work for some reason.
It goes through and all, but with like empty data.
Metamask shows differently when i do the same call from their front-end button. (I assume it does the same as remix does)
https://testnet.bscscan.com/token/0x84b9B910527Ad5C03A9Ca831909E21e236EA7b06#readContract
Here is how i try to get my contracts approval.
function approveTransfer(uint256 amount) public returns(string memory) {
uint256 approveAmt = amount * 10**18;
LINK.approve(_msgSender(),approveAmt);
approvedAmount = approveAmt;
}
Okay, so i kept searching and searching and searching....
Until i found something amazing on their discord channel. (It's most likely written somewhere else too).
Harry | Chainlink
The LINK token is an ERC677 with transferAndCall functionality. So
depending on how your smart contract function call that generates the
random number is made, you can change it to be a 'transferAndCall'
function instead of one that just does the VRF request, with the idea
being that it will transfer enough LINK to fulfill the VRF request.
Then in your consuming contract that does the VRF request, you
implement the 'onTokenTransfer' function which simply calls your other
function that does the VRF request. The end result of this is that
when the user transfers LINK to the contract, it automatically does a
VRF request all in the 1 single transaction.
So instead of the user pressing a button which calls the function in
your consuming contract to do the VRF request, they press a button
which does a 'transferAndCall' function from the LINK token contract,
which in turn transfer LINK to your consuming contract and calls the
'onTokenTransfer' function in your consuming contract, which then
calls your function to do the VRF request, which will be successfully
fulfilled because it just received LINK for the request
See an implementation of this in my previous hackathon entry "Link Gas Station"
https://github.com/pappas999/Link-Gas-Station/blob/master/contracts/WeatherCheck.sol
https://github.com/pappas999/Link-Gas-Station/blob/master/src/relayer/relayer.js
So in short, this is possible because my contract have the
function onTokenTransfer(address from, uint256 amount, bytes memory data) public {
receivedTokenTransfer = true;
lastDepositer = from;
lastDepositerAmountInLink = amount / 10**18;
}
I can therefor instead of sending LINK to my own contract, i can send LINK to LINK's contract address, with the data payload transferAndCall , MycontractAddress, and the amount of LINK my contract should receive.
Upon this payment is sent, chainlink will send my contract the payment and call the function called onTokenTransfer (On my contract). :)))
Ho0pe this helps someone in the future.
Not possible from within your contract, unless the external contract explicitly allows it or contains a security flaw using deprecated tx.origin instead of msg.sender.
See the last paragraph and code snippet in this answer to see how it could be misused if it were possible.
When your contract executes LINK's function, msg.sender in the LINK contract is now your contract - not the user.
Both transfer() and approve() (in order to call transferFrom() later) functions rely on msg.sender, which you need to be the user. But it's not - it's your contract.
When your contract delegates a call to LINK's function, the state changes are stored in your contract - not in the LINK.
But you'd need to store the state changes in the LINK contract, so this is not an option either.
I am studying how to make BEP-20 tokens. For this I copied the following contract in remix to be able to study it:
Contract in BscScan
If I copy the whole file and compile it in Remix, when I deploy it it doesn't show me any getters. No public view function appears. If I look at the contract displayed on the testnet, it doesn't have any supply of tokens either.
I separated the files and libraries for a better reading. And it is then, when I try to display it, that I get the following error:
VM error: revert. revert The transaction has been reverted to the initial state. Note: The called function should be payable if you send value and the value you send should be less than your current balance. Debug the transaction to get more information.
It gives me the feeling that this contract does not generate the tokens ... What am I wrong?
I managed to fix the problem. As I suspected, in order to deploy the contract I have to remove everything related to uniswap and cakeswap. This displays the contract correctly.
If you wanted to deploy the contract with the uniswap interfaces in injected web3, you would need the uniswap testnet.
I found a test address for cake here:
Binance Smart change tesnet