abi.encodeWithSignature不起作用

Question

pragma solidity ^0.5.3;

contract SimpleFallback{
    event FallbackCalledEvent(bytes data);
    event AddEvent(uint a, uint b, uint result);
    event DoubleEvent(uint a, uint b);
    event GetNameEvent(string);

    function() external{
        emit FallbackCalledEvent(msg.data);
    }

    function add(uint a, uint b) public returns(uint){
        // assert(a >= 0);
        // assert(b >= 0);
        // assert(a + b > a && a + b > b);

        uint _result = a + b;
        emit AddEvent(a, b, _result);

        return _result;
    }

    function double(uint a) public returns(uint){
        // assert(a >= 0);
        // assert(2*a >= 0 && 2*a >= a);
        uint _result = 2*a;

        emit DoubleEvent(a, _result);

        return _result;
    }

    function getName(string memory name) public returns(string memory){
        emit GetNameEvent(name);

        return name;
    }
}


contract RunTest{


    function callAddlTest(address other) public {
        // bytes4 messageId = bytes4(keccak256("add(uint, uint)"));
        // other.call(messageId, 5, 60);
        other.call(abi.encodeWithSignature("add(uint,uint)", 85, 60));
    }

    function callDoublelTest(address other) public {
        // bytes4 messageId = bytes4(keccak256("add(uint, uint)"));
        // other.call(messageId, 5, 60);
        other.call(abi.encodeWithSignature("double(uint)", 100));
    }

    function callgetNameTest(address other) public{
        other.call(abi.encodeWithSignature("getName(string)", "hello"));
    }
}

操作如下.

• 步骤1.部署2份合同；
• 步骤2.调用callAddlTest，收缩SimpleFallback的地址，事件日志如下所示，这表明调用add()失败，触发了回退函数。

[
    {
        "from": "0x038f160ad632409bfb18582241d9fd88c1a072ba",
        "topic": "0x5cd57a899be814fb3a40e18f9d1ba77420bbd22073d35165511f750aa70538b6",
        "event": "FallbackCalledEvent",
        "args": {
            "0": "0xb89663520000000000000000000000000000000000000000000000000000000000000055000000000000000000000000000000000000000000000000000000000000003c",
            "data": "0xb89663520000000000000000000000000000000000000000000000000000000000000055000000000000000000000000000000000000000000000000000000000000003c",
            "length": 1
        }
    }
]

• 步骤3.调用callDoubleTest，收缩SimpleFallback的地址，事件日志如下所示，这表明调用double()失败，触发了回退函数。

[
    {
        "from": "0x038f160ad632409bfb18582241d9fd88c1a072ba",
        "topic": "0x5cd57a899be814fb3a40e18f9d1ba77420bbd22073d35165511f750aa70538b6",
        "event": "FallbackCalledEvent",
        "args": {
            "0": "0xd524bc570000000000000000000000000000000000000000000000000000000000000064",
            "data": "0xd524bc570000000000000000000000000000000000000000000000000000000000000064",
            "length": 1
        }
    }
]

• 步骤4.使用收缩SimpleFallback的地址调用callgetNameTest，事件日志如下所示，这表明调用了getName()。

    {
        "from": "0x038f160ad632409bfb18582241d9fd88c1a072ba",
        "topic": "0x26c73f7f14382f5db0b9f94dd29ff8938f2e4be69fb13e0825ece287e8e538d5",
        "event": "GetNameEvent",
        "args": {
            "0": "hello",
            "length": 1
        }
    }
]

问题：

对于调用(abi.encodeWithSignature())，为什么：- 1)other.call(abi.encodeWithSignature("add(uint,uint)", 85, 60));不工作？- 2)other.call(abi.encodeWithSignature("double(uint)", 100));不工作？- 3)other.call(abi.encodeWithSignature("getName(string)", "hello"));工作吗？- 4) encodeWithSignature不支持多个参数，比较1)和3)？encodeWithSignature不支持uint参数吗，比较2)和3)？

Answer 1

我已经找到了根本原因。它应该使用类型的全名，而不是它们的别名，所以应该是uint256而不是uint。

Answer 2

(bool success, bytes memory response) = address(_address).call(abi.encodeWithSignature("transfer(address,address,uint256)", msg.sender, _to, _amount));

第一个参数在encodeWithSignature方法中不应该包含任何空格。

Answer 3

都是关于太空的

other.call(abi.encodeWithSignature("add(uint,uint)", 85, 60));

改为：

other.call(abi.encodeWithSignature("add(uint,uint)",85,60));