solidity基础-delegateCall

delegateCall 用于重定向父合约；

A 合约越来调用B1， 将地址改为 B2 就可以调用 B2

 

 

合约B1

contract B {

  uint public num;
  uint public value;

  function setVars(uint _num) public payable{
    num = _num;
    value = msg.value;
  }

}

合约A

contract A{
  uint public num;
  uint public value;
  address public b;

  function setVars(uint _num) public payable{
    (bool success, bytes memory data) = b.delegatecall(
        abi.encodeWithSignature("setVars(uint256)", _num)
    );
  }

  function setB(address _b) external{
    b = _b;
  }
}

 部署

获得 num = 1

 

 

B2

contract B2 {

  uint public num;
  uint public value;

  function setVars(uint _num) public payable{
    num = _num + 2;
    value = msg.value;
  }

}

编译部署完 B2,  地址设置 B2 合约

 

 调用 合约 A 的 setVars 获得 num = 3;