获取 Chainlink ETH/USD 价格反馈答案为 uint256 而不是 int solidity

Posted 2023-02-16

【中文标题】获取 Chainlink ETH/USD 价格反馈答案为 uint256 而不是 int solidity

【英文标题】：Get Chainlink ETH/USD Price Feed answer as uint256 instead of int solidity

【发布时间】：2021-12-15 09:21:55

【问题描述】：

我想使用最新的 ETH 美元价格来计算我可以从 AAVE 借多少 USDC。

我遵循了所有教程：

interface AggregatorV3Interface 
  function decimals() external view returns (uint8);

  function description() external view returns (string memory);

  function version() external view returns (uint256);

  // getRoundData and latestRoundData should both raise "No data present"
  // if they do not have data to report, instead of returning unset values
  // which could be misinterpreted as actual reported values.
  function getRoundData(uint80 _roundId)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  function latestRoundData()
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

将合约用于 ETH/USD 价格馈送：

https://etherscan.io/address/0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419

AggregatorV3Interface internal priceFeed = AggregatorV3Interface(0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419);

创建了获取价格的函数：

 function getLatestPrice() public view returns (int) 
        (
            uint80 roundID, 
            int price,
            uint startedAt,
            uint timeStamp,
            uint80 answeredInRound
        ) = priceFeed.latestRoundData();
        return price;
    

而我要调用的函数就是这个：

 AaveLendingPool.borrow(address(USDT),getLatestPrice(), 1, 0, address(this));

这是我得到的错误：

TypeError: Type int256 is not implicitly convertible to expected type uint256.

我需要将 int 转换为单位

【参考方案1】：

您可以使用以下语法将int 类型转换为uint：uint256(input)

例子：

pragma solidity ^0.8;

contract MyContract 
    function foo() external 
        borrow(uint256(getLatestPrice()));
    
    
    function getLatestPrice() internal returns (int256) 
        return 1;
    
    
    function borrow(uint256 _number) internal