TypeError：覆蓋函式將狀態可變性從“view”更改為“nonpayable”

我有2個問題。

1. 部署契約時沒有設置我的建構子值。所有需要name、symbol、decimals和的函式totalSupply。

2a. 函式name()、symbol()、decimals()和totalSupply()都balanceOf()標記為TypeError: Overriding function 將狀態可變性從“view”更改為“nonpayable”。

2b。如果我添加view了我不應該添加的，我將balanceOf被標記為view在除此之外的所有內容上使用balanceOf。 typeError: Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

abstract contract ERC20{
   function name() external virtual view returns (string memory);
   function symbol() external virtual view returns (string memory);
   function decimals() external virtual view returns (uint8);
   function totalSupply() external virtual view returns (uint256);
   function balanceOf(address _owner) external virtual view returns (uint256 balance);
   function transfer(address _to, uint256 _value) external virtual returns (bool success);
   function transferFrom(address _from, address _to, uint256 _value) external virtual returns (bool success);
   function approve(address _spender, uint256 _value) external virtual returns (bool success);
   function allowance(address _owner, address _spender) external virtual view returns (uint256 remaining);

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


   }

   contract Ownership{

       address public contractOwner;
       address public newContractOwner;

       constructor(){
           contractOwner = msg.sender;
       }

       function changeOwnership(address _newContractOwner) external returns(bool success){
           require(msg.sender == contractOwner, "Not contract owner");
           _newContractOwner = newContractOwner;
           return success;
       }

       function approveOwnershipChange() external returns(bool success){
           require(msg.sender == newContractOwner, "Not the new contract owner");
           newContractOwner = contractOwner;
           return success;
       }
   }


   contract FullContact is ERC20, Ownership{

       constructor(string memory name_, 
                   string memory symbol_,
                   uint8 decimals_,
                   uint256 totalSupply_ ){
       }

       string public _name;
       string _symbol;

       uint8 _decimals;
       uint256 _totalSupply;

       mapping(address => uint256) _balance;
       mapping(address => mapping( address => uint256)) _allowance; 
       mapping(address => uint256) minter;


       function name() external override returns (string memory){
           _name = "Fog Of War";
           return _name;
       }

       function symbol() external override returns (string memory){
           _symbol = "FOW";
           return _symbol;

       }
       function decimals() external override returns (uint8){
           _decimals = 18;
           return _decimals;
       }

       function totalSupply() external override returns (uint256){
           _totalSupply = 100000000;
           return _totalSupply;
       } 

       function balanceOf(address _owner) external override view returns (uint256 balance){
           return _balance[_owner];
       }

       function transfer(address _to, uint256 _value) external override returns (bool success){
           require(_balance[msg.sender] >= _value, "Insufficent Funds");
           _balance[msg.sender] -= _value;
           _balance[_to] += _value;
           emit Transfer(msg.sender, _to, _value);
           return success;
       }

       function transferFrom(address _from, address _to, uint256 _value) external override returns (bool success){
           uint256 approvedAmount = _allowance[_from][_to];
           require(approvedAmount <= _value, "Insufficent allowance");
           _balance[_from] -= _value;
           _balance[_to] += _value;
           emit Transfer(_from, _to, _value);
           return success;
       }

       function approve(address _spender, uint256 _value) external override returns (bool success){
           require(_balance[msg.sender] >= _value, "Insufficent Funds");
           _allowance[msg.sender][_spender] = _value;
           emit Approval(msg.sender, _spender, _value);
           return success;

       }
       function allowance(address _owner, address _spender) external override view returns (uint256 remaining){
           return _allowance[_owner][_spender];
       }


   }

我認為您不能在頂部定義的抽象契約中使用“視圖”。您使用的模板用於介面。介面提供覆蓋“視圖”功能，但不提供抽象契約。因為現在您正在做的是嘗試在視圖函式中為字元串設置一個值，這是不允許的。

我建議您將抽象合約更改為介面，或使用標準 ERC20 合約。

引用自：https://ethereum.stackexchange.com/questions/126978