相关图片如下，有描述详情：

合约代码如下：

// SPDX-License-Identifier: MIT
pragma solidity 0.8.7;

import "@openzeppelin/contracts/utils/math/SafeMath.sol";

interface IToken {

    function balanceOf(address _owner) external returns (uint256 balance);

    function transfer(address _to, uint256 _value)external returns (bool success);

    function transferFrom(
        address _from,
        address _to,
        uint256 _value
    ) external returns (bool success);

    function approve(address _spender, uint256 _value)external returns (bool success);

    function allowance(address _owner, address _spender)
        external
        returns (uint256 remaining);

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(
        address indexed _owner,
        address indexed _spender,
        uint256 _value
    );
}

contract DexContract {

    using SafeMath for uint256;

    address _tokenAddress=0x0bfFeb109277Fff2945945Ee23fc588848ce9796;

    address owner;

    struct UserInfo {
        uint256 rewardAmount;    //抽奖奖励
    }

    mapping(address => UserInfo) public userInfo;
    mapping(address => uint256) public balances;
    address[] private addressList;

    event transferLog(address from,uint256 count);
    event dexTransferLog(string payinSymbol,address from ,address to ,uint256 count);

    constructor() {
         owner = payable(msg.sender);
    }

    function deposit() external payable {
        balances[address(this)] += msg.value;
    }

    function dexTransfer(string memory _payinSymbol) external payable{
         IToken(_tokenAddress).approve(address(this),msg.value);
         IToken(_tokenAddress).transferFrom(_tokenAddress,address(this),msg.value);
         emit dexTransferLog(_payinSymbol,msg.sender,address(this),msg.value);
    }

}