如何在智能合約中接收 ERC20

您好，我對 ERC20 很陌生，我嘗試研究一些東西，但我腦海中的概念可能不正確。我正在嘗試創建接收一定數量 ERC20 的智能合約，驗證輸入數量，如果沒問題，它會繼續下面的邏輯。智能合約看起來像這樣：

contract Orders {
uint256 public counter;

function deposit() public payable {
  // Here we validate if sended USDT for example is higher than 50, and if so we increment the counter

 counter = counter + 1
}
}

如何驗證每筆存款的 ERC20 發送金額

試試這個：

//SPDX-License-Identifier: MIT
pragma solidity 0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract Orders is Ownable {
 uint256 public counter;
 address token;

 constructor(address _token) {
   token = _token;
 }

 function deposit(uint _amount) public payable {
   // Set the minimum amount to 1 token (in this case I'm using LINK token)
   uint _minAmount = 1*(10**18);
   // Here we validate if sended USDT for example is higher than 50, and if so we increment the counter
   require(_amount >= _minAmount, "Amount less than minimum amount");
   // I call the function of IERC20 contract to transfer the token from the user (that he's interacting with the contract) to
   // the smart contract  
   IERC20(token).transferFrom(msg.sender, address(this), _amount);
   counter = counter + 1;
 }

 // This function allow you to see how many tokens have the smart contract 
 function getContractBalance() public onlyOwner view returns(uint){
   return IERC20(token).balanceOf(address(this));
 }
}

**注意：**請記住批准智能合約來使用您的代幣。

引用自：https://ethereum.stackexchange.com/questions/123449