TypeError:类型bytes32[]内存不能隐式转换为预期类型bytes32[3]存储引用

Question

包装器类来实例化其他类

contract WrapperCreator {

    function WrapperCreator() {
    }

    function createTopic(string name, bytes32[] resultNames, uint256 endBlock)
        returns (Topic tokenAddress)
    {
        return new Topic(name, resultNames, bettingEndBlock);
    }
}

WrapperCreator

测试用例

pragma solidity ^0.4.0;

import "truffle/Assert.sol";
import "truffle/DeployedAddresses.sol";
import "../contracts/WrapperCreator.sol";

contract TestWrapperCreator {
    bytes32[3] resultNames;

    function beforeEach() {
        resultNames = new bytes32[](3);
        resultNames[0] = "first";
        resultNames[1] = "second";
        resultNames[2] = "third";
    }

    function testConstructor() {
        WrapperCreator wrapperCreator = WrapperCreator(DeployedAddresses.WrapperCreator());
        Topic testTopic = wrapperCreator.createTopic("test", resultNames, 1000000);

        Assert.equal(testTopic.getResultName(0), "first", "Expected result name matches");
    }
}

我得到以下错误：

,../test/TestWrapperCreator.sol:11:23: TypeError: Type bytes32[] memory is not implicitly convertible to expected type bytes32[3] storage ref.
        resultNames = new bytes32[](3);
                      ^--------------^
,../test/TestWrapperCreator.sol:19:60: TypeError: Invalid type for argument in function call. Invalid implicit conversion from bytes32[3] storage ref to bytes32[] memory requested.
        Topic testTopic = eventCreator.createTopic("test", resultNames, 1000000);

Answer 1

createTopic方法期望使用bytes32[]类型，这是一个动态的bytes32数组，但是您要向它传递一个bytes32[3]，一个固定大小的bytes32数组。

变化

bytes32[3] resultNames;

至

bytes32[] resultNames;

还请注意，您正在传递一个存储引用，因此如果方法修改数组，下一个测试将读取更新的值。

Answer 2

或者，您可以使用：

bytes32[3] resultNames;
function beforeEach() {

    bytes32[3] storage a ;
    resultNames =a;
    resultNames[0] = "first";
    resultNames[1] = "second";
    resultNames[2] = "third";
}