ERC20令牌从交易哈希中转移信息

Question

EtherScan提供了用于交易详细信息的API，它是Geth / Parity代理API的一部分，名称为eth_getTransactionByHash，但是我无法获得有关已传输了什么ERC20令牌以及传输了多少令牌的信息。

我需要在交易哈希的帮助下传输令牌详细信息和令牌数量。

Answer 1

您使用了错误的API。

要获取ERC20转账的信息，您需要交易收据，因为转账信息记录在转账事件日志中。您应该使用eth_getTransactionReceipt。

对于this tx，这会给您这样的答复：

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "blockHash": "0xc5e5a515898983d1370d40b03fc05ae08be861af746a1577796153a149a1bb20",
    "blockNumber": "0x5ff5dd",
    "contractAddress": null,
    "cumulativeGasUsed": "0xe85fb",
    "from": "0xd7afd4441fccc118b9207b0e136f4ef9319b3c79",
    "gasUsed": "0x9034",
    "logs": [
      {
        "address": "0x0d8775f648430679a709e98d2b0cb6250d2887ef",
        "topics": [
          "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
          "0x000000000000000000000000d7afd4441fccc118b9207b0e136f4ef9319b3c79",
          "0x00000000000000000000000069d9e9aff57ec73582ad1ce441726dba7ea78fe0"
        ],
        "data": "0x0000000000000000000000000000000000000000000001054aefee8ba6d00000",
        "blockNumber": "0x5ff5dd",
        "transactionHash": "0x3265c1461d3f167c756fbc062ae3a2dc279b44a9c3ca2194271d4251cd0c1655",
        "transactionIndex": "0x1b",
        "blockHash": "0xc5e5a515898983d1370d40b03fc05ae08be861af746a1577796153a149a1bb20",
        "logIndex": "0xa",
        "removed": false
      }
    ],
    "logsBloom": "0x04000000002000000200000000000000002000000000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000008000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000200010000000000000000000000000000000000000000000000100000000000000000200000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
    "status": "0x1",
    "to": "0x0d8775f648430679a709e98d2b0cb6250d2887ef",
    "transactionHash": "0x3265c1461d3f167c756fbc062ae3a2dc279b44a9c3ca2194271d4251cd0c1655",
    "transactionIndex": "0x1b"
  }
}

其中，此日志部分很重要。

ERC20传输日志的格式为Transfer(address from, address to, uint256 value)。当您为keccak使用Transfer(address,address,uint256)哈希时，您将获得主题的0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef，如上面的响应所示。

该日志中的下两个值分别是from和to地址，它们以常规方式打包为ETH（零填充直到32字节）。最后，日志中的data是已传输的ERC20令牌的值（在此示例中为BAT）。

发出日志address的{​​{1}}是令牌合约。然后，您可以使用0x0d8775f648430679a709e98d2b0cb6250d2887ef API从该合同中读取令牌符号，名称和小数，以读取令牌信息。