我将如何用直接从sbt换DAI的方式来交换ETH？

Question

首先，我喜欢sbt-ethereum。这是一种活泼和绝对的乐趣。在完成了教程的契约交互部分之后，我想测试一个活合同。

我想与uniswap.io的ETH交易合同直接从sbt-ethereum获得2 DAI.

1. 我通过在dai-token上滚动找到了以太扫描地址
2. 然后使用Uniswap文档获取uniswap-factory协议地址。
3. 名为ethTransactionView uniswap-factory getExchange dai-token
4. 这将返回uniswap-dai-exchange地址(0x09cabec1ead1c0ba254b09efb3ee13841712be14)
5. 我验证了合同ABI 关于以太扫描是否与github版本匹配。
6. 然后我试着用5分钟的计时器得到两个戴。不同的输入参数组合(请参阅A到E)，包括一些带有[ETH to pay, optional]字段的输入参数组合，在相同的错误情况下失败。
7. 我检查了dai合同，它似乎是18个小数，所以我把DAI的输入改为2e18。我尝试了以太和芬尼面额的可选付款方式。我还使用了ethToTokenSwapInput，指定了ETH的数量，而不是DAI，同样的结果。

所需com.mchange.sc.v2.jsonrpc.package$JsonrpcException:气体超过允许量或交易总是失败:没有进一步的信息

我肯定这是我做的很简单的事情。寄出的钱夹由价值超过5 DAI的ETH资助。

Any想法？

注意:我无法将新的sbt-ethereum标记按原计划创建为声誉<150。

答：ethTransactionInvoke uniswap-dai-exchange ethToTokenSwapOutput 2 300

B：ethTransactionInvoke uniswap-dai-exchange ethToTokenSwapOutput 2 300 15 finney

C：ethTransactionInvoke uniswap-dai-exchange ethToTokenSwapOutput 2000000000000000000 300

D：ethTransactionInvoke uniswap-dai-exchange ethToTokenSwapOutput 2000000000000000000 300 15 finney

E：ethTransactionInvoke uniswap-dai-exchange ethToTokenSwapOutput 2000000000000000000 300 0.015 ether

Answer 1

首先，感谢您尝试了sbt-ethereum (并且喜欢它！)。

我想我可以做你想做的交易。有两个问题：

1. 正如@Ismael所说，截止日期应该是unix时间戳。(考虑到这些方法的流行程度，我可能应该添加一个实用程序，以便在sbt-ethereum中轻松地计算它们。)
2. 函数的调用。被标记为@payable，并且确实需要支付您愿意为交换提供的乙醚的数量。在我看来，sbt-ethereum教程没有很好地强调这一点，但是在调用payable函数时，在提供函数参数之后，您可以提供希望作为一个数字和单位支付的金额。(更新：我看到您已经注意到并尝试了！因此，这基本上只是最后期限。

另一个问题是戴小数是18，所以如果我们只想要2个DAI代币，我们需要2加一个0。( uint解析器在sbt-ethereum中不支持科学表示法，这是另一件需要纠正的事情！)

所以，当一切都说好了，我们就有了.

> ethTransactionInvoke unverified-uniswap-dai-exchange ethToTokenSwapOutput 2000000000000000000 1557109479 0.015 ether
[info] Unlocking address '0x465e79b940bc2157e4259ff6b2d92f454497f1e4' (on chain with ID 1, aliases ['default-sender','testing0'])
Enter passphrase or hex private key for address '0x465e79b940bc2157e4259ff6b2d92f454497f1e4': *******************
[info] V3 wallet(s) found for '0x465e79b940bc2157e4259ff6b2d92f454497f1e4' (aliases ['default-sender','testing0'])

==> T R A N S A C T I O N   S U B M I S S I O N   R E Q U E S T
==>
==> The transaction would be a message with...
==>   To:    0x09cabec1ead1c0ba254b09efb3ee13841712be14 (with aliases ['unverified-uniswap-dai-exchange'] on chain with ID 1)
==>   From:  0x465e79b940bc2157e4259ff6b2d92f454497f1e4 (with aliases ['default-sender','testing0'] on chain with ID 1)
==>   Data:  0x6b1d4db70000000000000000000000000000000000000000000000001bc16d674ec80000000000000000000000000000000000000000000000000000000000005ccf9ae7
==>   Value: 0.015 Ether
==>
==> The transaction is signed with Chain ID 1 (which correctly matches the current session's 'ethNodeChainId').
==>
==> According to the ABI currently associated with the 'to' address, this message would amount to the following method call...
==>   Function called: ethToTokenSwapOutput(uint256,uint256)
==>     Arg 1 [name=tokens_bought, type=uint256]: 2000000000000000000
==>     Arg 2 [name=deadline, type=uint256]: 1557109479
==>
==> The nonce of the transaction would be 407.
==>
==> $$ The transaction you have requested could use up to 66235 units of gas.
==> $$ You would pay 3 gwei for each unit of gas, for a maximum cost of 0.000198705 ether.
==> $$ This is worth 0.031652712975 USD (according to Coinbase at 7:20 PM).
==> $$ You would also send 0.015 ether (2.389425 USD), for a maximum total cost of 0.015198705 ether (2.421077712975 USD).

Would you like to submit this transaction? [y/n] y
A transaction with hash '0x0509bafc336c760f21e6c7a1c491d7ba86a6c17c18ec46eec8d87d4995afd8e6' will be submitted. Please wait.
[info] Called function 'ethToTokenSwapOutput', with args '2000000000000000000, 1557109479', sending 15000000000000000 wei to address '0x09cabec1ead1c0ba254b09efb3ee13841712be14' in transaction '0x0509bafc336c760f21e6c7a1c491d7ba86a6c17c18ec46eec8d87d4995afd8e6'.
[info] Waiting for the transaction to be mined (will wait up to 5 minutes).
[info] Transaction Receipt:
[info]        Transaction Hash:    0x0509bafc336c760f21e6c7a1c491d7ba86a6c17c18ec46eec8d87d4995afd8e6
[info]        Transaction Index:   122
[info]        Transaction Status:  SUCCEEDED
[info]        Block Hash:          0x3257d8fd31b49c2c7d55d72c0fddd01f02b92a3326529ed903fdd0e6cb520f9d
[info]        Block Number:        7704627
[info]        From:                0x465e79b940bc2157e4259ff6b2d92f454497f1e4
[info]        To:                  0x09cabec1ead1c0ba254b09efb3ee13841712be14
[info]        Cumulative Gas Used: 6482478
[info]        Gas Used:            54719
[info]        Contract Address:    None
[info]        Logs:                0 => EthLogEntry [source=0x89d24a6b4ccb1b6faa2625fe562bdd9a23260359] (
[info]                                    topics=[
[info]                                      0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef,
[info]                                      0x00000000000000000000000009cabec1ead1c0ba254b09efb3ee13841712be14,
[info]                                      0x000000000000000000000000465e79b940bc2157e4259ff6b2d92f454497f1e4
[info]                                    ],
[info]                                    data=0000000000000000000000000000000000000000000000001bc16d674ec80000
[info]                                  ),
[info]                             1 => EthLogEntry [source=0x09cabec1ead1c0ba254b09efb3ee13841712be14] (
[info]                                    topics=[
[info]                                      0xcd60aa75dea3072fbc07ae6d7d856b5dc5f4eee88854f5b4abf7b680ef8bc50f,
[info]                                      0x000000000000000000000000465e79b940bc2157e4259ff6b2d92f454497f1e4,
[info]                                      0x000000000000000000000000000000000000000000000000002c13f43dbb6c42,
[info]                                      0x0000000000000000000000000000000000000000000000001bc16d674ec80000
[info]                                    ],
[info]                                    data=
[info]                                  )
[info]        Events:              0 => Transfer [source=0x89d24a6b4ccb1b6faa2625fe562bdd9a23260359] (
[info]                                    _from (of type address): 0x09cabec1ead1c0ba254b09efb3ee13841712be14,
[info]                                    _to (of type address): 0x465e79b940bc2157e4259ff6b2d92f454497f1e4,
[info]                                    _value (of type uint256): 2000000000000000000
[info]                                  ),
[info]                             1 => TokenPurchase [source=0x09cabec1ead1c0ba254b09efb3ee13841712be14] (
[info]                                    buyer (of type address): 0x465e79b940bc2157e4259ff6b2d92f454497f1e4,
[info]                                    eth_sold (of type uint256): 12406838703909954,
[info]                                    tokens_bought (of type uint256): 2000000000000000000
[info]                                  )
[success] Total time: 37 s, completed May 5, 2019 7:20:27 PM

sbt:ethdocstore> ethTransactionView 0x89d24a6b4ccb1b6faa2625fe562bdd9a23260359 balanceOf testing0
[info] The function 'balanceOf' yields 1 result.
[info]  + Result 1 of type 'uint256', named 'balance', is 2000000000000000002
[success] Total time: 1 s, completed May 5, 2019 7:26:36 PM

帐户余额末尾的额外2个原子是由于我最初的尝试，而不是所有这些额外的零。

您可以看到，如果您检查成功的交易，对于我的2 DAI我发送了0.015 ether，但是(在一个“内部事务”)得到0.002593161296090046 ether作为改变。

再次感谢你给sbt-ethereum一次机会。我希望这能帮到你!

附注：如果您想在sbt-ethereum中计算300秒(5分钟)的最后期限，您可以这样做。

> consoleQuick
[info] Starting scala interpreter...
Welcome to Scala 2.12.7 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_172).
Type in expressions for evaluation. Or try :help.

scala> (System.currentTimeMillis / 1000) + 300
res0: Long = 1557110378

scala> 

显然，最好不要掉进Scala来完成这个任务。