函数调用的原因不明

Question

Tbh，很难解释标题的原因，顺便说一句，我有一份预售测试合同，允许用户购买令牌，一旦硬顶达到停止卖出更多的令牌。

这是合同

contract TESTPresale is ReentrancyGuard {
    using SafeMath for uint256;
    using SafeBEP20 for IBEP20;
    // Maps user to the number of tokens owned
    mapping(address => uint256) public tokensOwned;
    // The number of unclaimed tokens the user has
    mapping(address => uint256) public tokensUnclaimed;

    // TEST token
    IBEP20 public TEST;
    // USDC token
    IBEP20 public USDC;

    // Sale active
    bool isSaleActive;
    // Claim active
    bool isClaimActive;
    // Total TEST sold
    uint256 totalTokensSold = 0;
    // Price of presale TEST, 1 USDC
    
    uint256 public testPerUsdc = 1e18/uint256(950000);
    // Amount of USDC received in presale
    uint256 usdcReceived = 0;

    uint256 HardCap = 85000 * 10 ** 18; // 85,000

    event TokenBuy(address user, uint256 tokens);
    event TokenClaim(address user, uint256 tokens);

    constructor(
        address _TEST,
        address _USDC
    ) public {
        TEST = IBEP20(_TEST);
        USDC = IBEP20(_USDC);
    }

    function setTestPerUsdc(uint256 _testPerUsdc) public onlyOwner{
        testPerUsdc = _testPerUsdc;
    }

    function buy(uint256 _amount) public nonReentrant {
        require(isSaleActive, "Presale has not started");
        
        
        address _buyer = msg.sender;
        uint256 tokens = _amount.mul(testPerUsdc);
        require ( totalTokensSold + tokens <= HardCap, "presale hardcap reached");

        USDC.safeTransferFrom(msg.sender, address(this), _amount);

        tokensOwned[_buyer] = tokensOwned[_buyer].add(tokens);
        tokensUnclaimed[_buyer] = tokensUnclaimed[_buyer].add(tokens);
        totalTokensSold = totalTokensSold.add(tokens);

        usdcReceived = usdcReceived.add(_amount);
        emit TokenBuy(msg.sender, tokens);
    }


    function getTotalTokensSold() public view returns (uint256) {
        return totalTokensSold;
    }


    function getTESTTokensLeft() external view returns (uint256) {
        return TEST.balanceOf(address(this));
    }


    .........
    
}

在Constructor中，我有测试令牌和USDC，我对这两个输入都使用了测试令牌

但是，每当我发送50k令牌到预售合同，然后尝试用至少1000000000000000000卫士=1测试令牌测试购买函数时，我就会得到这个错误。

Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending?
Internal JSON-RPC error.
{
"code": 3,
"message": "execution reverted: presale hardcap reached",
"data": "0x0.......}

但是当我想买30000000000魏= 0.00000003之类的东西时，它工作得很好。

有人能帮忙吗?问题在哪里？

Answer 1

在您的代码中，您有以下要求条件：

require ( totalTokensSold + tokens <= HardCap, "presale hardcap reached");

正如我们在您的代码中所看到的

totalTokensSold = 0
tokens = _amount.mul(testPerUsdc)-->
tokens = 50k * 1= 50000*10**18 * 1e18/uint256(950000)--> 
(to make easier change 95000 to 100000) -->
tokens = 50k * 1= 50000*10**18 * 1e13 
and this is greater than your HardcCap of 85*10**1e18

错误应该大约出现在2e13左右，在第一个例子中，值高于这个值，这就是它失败的原因，第二个错误出现在下面，而不是失败！

希望能帮上忙！

Answer 2

您必须定义testPerUsdc在每个wei基础上。

例如：

testPerUsdc = No of token in 1 wei usdc * 10**18/10**decimalUSDC
            = No of token in 1 wei usdc * 10**18 / 10**9
            = No of otken in 1 wei usdc * 10**9

如果是No of token in 1 usdc = 1，那么在1weusdc中，带有小数的9将是令牌的= 1 * 10**9 wei。