前言
合约间偶尔也有需要互相调用的场景, 跟Go的接口声明挺像的
示例代码
调用加密猫和usdt的合约, 分别获取加密猫信息和usdt余额
pragma solidity ^0.4.19;
contract KittyInterface {
/// @notice Returns all the relevant information about a specific kitty.
/// @param _id The ID of the kitty of interest.
function getKitty(uint256 _id)
external
view
returns (
bool isGestating,
bool isReady,
uint256 cooldownIndex,
uint256 nextActionAt,
uint256 siringWithId,
uint256 birthTime,
uint256 matronId,
uint256 sireId,
uint256 generation,
uint256 genes
);
}
contract TetherInterface {
function balanceOf(address who) public constant returns (uint);
}
contract HelloWord {
KittyInterface kittyContract;
TetherInterface tetherContract;
function HelloWord(address _kittyAddress, address _tetherAddress) {
kittyContract = KittyInterface(_kittyAddress);
tetherContract = TetherInterface(_tetherAddress);
}
// @dev getKittyInfo 获取加密猫的信息
function getKittyInfo(uint256 _id) public returns (bool) {
bool isReady;
(,isReady,,,,,,,,) = kittyContract.getKitty(_id);
return isReady;
}
// @dev getTetherBalance 获取usdt余额
function getTetherBalance(address who) public returns (uint) {
return tetherContract.balanceOf(who);
}
}
声明对应的interface合约接口, 然后通过合约地址初始化调用就可以了
