Solidity智能合约调用智能合约

来源：https://medium.com/@blockchain101/calling-the-function-of-another-contract-in-solidity-f9edfa921f4c

合约一：

pragma solidity ^0.4.18;
contract Deployed {
uint public a = 1;

function setA(uint _a) public returns (uint) {
a = _a;
return a;
}

}

合约二调用合约一：

pragma solidity ^0.4.18;
contract Deployed {

function setA(uint) public returns (uint) {}

function a() public pure returns (uint) {}

}
contract Existing  {

Deployed dc;

function Existing(address _t) public {
dc = Deployed(_t);
}

function getA() public view returns (uint result) {
return dc.a();
}

function setA(uint _val) public returns (uint result) {
dc.setA(_val);
return _val;
}

}