Question

I know this question has been asked too frequently. I apologise, but I did not understand much of the answers. I ve been trying to create a Staking Contract but this error has stumped me. This is not the stake function code itself, just the transferring part. This is the code:

   function stake(uint256 _amount) public {
        stakingToken.transferFrom(msg.sender, address(this), _amount);
        stakingToken.approve(msg.sender, _amount);
    }

This is the error:

The transaction has been reverted to the initial state.
Reason provided by the contract: "ERC20: insufficient allowance".
Debug the transaction to get more information.

我先尝试将批准职能放在首位,最后是移交。 Ive利用转账职能进行审判,但都出现了同样的错误。

我也把我的天然气限额提高到12000 000,我也试图增加甲型六氯环己烷,但没有任何工作。

如果问你,我很抱歉,我只想作一个能够解决我问题的翔实答案。

May you reach the stars.

Answer 1

问题在于将<条码>核准功能置于<条码><><>:

stakingToken.approve(msg.sender, _amount);

这里的控制流动是为了说明:

     stake()                  approve()
user   -->   staking contract    -->   staking token

从象征性的角度来看,<代码>核准电话是采集合同,允许用户将taking合同花在上。

But what we wanted is the opposite: the user to allow the staking contract to spend the user s tokens.

<>Solution:为了进行所期望的转让,你必须有两个单独的交易:

The user calls approve directly on the staking token to allow the staking contract to spend the user s tokens.

     approve()
user    -->   staking token

The user calls stake, which transfers the token from the user to the staking contract.

     stake()
user   -->   staking contract

友情链接