欢迎订阅专栏：3分钟Solidity--智能合约--Web3区块链技术必学
Chronicle 是一个独立的、品牌化的预言机网络服务商 你可以把 Chronicle 想象成一家专门提供“天气数据”的公司，任何有需要的机构（包括DeFi协议）都可以付费订阅；而 Uniswap 的预言机更像是交易所自己生成的“内部交易指数”，主要用于其自身的生态系统内。
Chronicle价格预言机
ETH / USD 价格预言机
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.16;
/**
* @title OracleReader
* @notice A simple contract to read from Chronicle oracles
* @dev To see the full repository, visit https://github.com/chronicleprotocol/OracleReader-Example.
* @dev Addresses in this contract are hardcoded for the Sepolia testnet.
* For other supported networks, check the https://chroniclelabs.org/dashboard/oracles.
*/
contract OracleReader {
/**
* @notice The Chronicle oracle to read from.
* Chronicle_ETH_USD_3:0xdd6D76262Fd7BdDe428dcfCd94386EbAe0151603
* Network: Sepolia
*/
IChronicle public chronicle = IChronicle(address(0xdd6D76262Fd7BdDe428dcfCd94386EbAe0151603));
/**
* @notice The SelfKisser granting access to Chronicle oracles.
* SelfKisser_1:0x0Dcc19657007713483A5cA76e6A7bbe5f56EA37d
* Network: Sepolia
* For a full list of SelfKisser addresses on different Testnet networks
* please check here https://docs.chroniclelabs.org/Developers/tutorials/Remix
*/
ISelfKisser public selfKisser = ISelfKisser(address(0x0Dcc19657007713483A5cA76e6A7bbe5f56EA37d));
constructor() {
// Note to add address(this) to chronicle oracle's whitelist.
// This allows the contract to read from the chronicle oracle.
selfKisser.selfKiss(address(chronicle));
}
/**
* @notice Function to read the latest data from the Chronicle oracle.
* @return val The current value returned by the oracle.
* @return age The timestamp of the last update from the oracle.
*/
function read() external view returns (uint256 val, uint256 age) {
(val, age) = chronicle.readWithAge();
}
}
// Copied from [chronicle-std](https://github.com/chronicleprotocol/chronicle-std/blob/main/src/IChronicle.sol).
interface IChronicle {
/**
* @notice Returns the oracle's current value.
* @dev Reverts if no value set.
* @return value The oracle's current value.
*/
function read() external view returns (uint256 value);
/**
* @notice Returns the oracle's current value and its age.
* @dev Reverts if no value set.
* @return value The oracle's current value using 18 decimals places.
* @return age The value's age as a Unix Timestamp .
* */
function readWithAge() external view returns (uint256 value, uint256 age);
}
// Copied from [self-kisser](https://github.com/chronicleprotocol/self-kisser/blob/main/src/ISelfKisser.sol).
interface ISelfKisser {
/// @notice Kisses caller on address.
function selfKiss(address oracle) external;
}
