［悬赏］solidity 编写，list function不成功

Question

pragma solidity ^0.5.0;

contract Dice {

enum diceState { stationary, rolling }

struct dice {
    uint8 numberOfSides;
    uint8 color;
    uint8 currentNumber;
    diceState state;
    uint256 creationValue;
    address owner;
    address prevOwner;
    uint8 luckyTimes;
    uint256 price;
    bool listed;
}

event rolling (uint256 diceId);
event rolled (uint256 diceId, uint8 newNumber);
event luckytimesEvent (uint256 diceId, uint8 luckyTimes);

uint256 public numDices = 0;
mapping(uint256 => dice) public dices;

//function to create a new dice, and add to 'dices' map. requires at least 0.01ETH to create
function add(
    uint8 numberOfSides,
    uint8 color
) public payable returns(uint256) {
    require(numberOfSides > 0);
    require(msg.value > 0.01 ether, "at least 0.01 ETH is needed to spawn a new dice");

    //new dice object
    dice memory newDice = dice(
        numberOfSides,
        color,
        (uint8)(block.timestamp % numberOfSides) + 1,  //non-secure random number
        diceState.stationary,
        msg.value,
        msg.sender,  //owner
        address(0),
        0,
        0,
        false
    );

    uint256 newDiceId = numDices++;
    dices[newDiceId] = newDice; //commit to state variable
    return newDiceId;   //return new diceId
}

//modifier to ensure a function is callable only by its owner    
modifier ownerOnly(uint256 diceId) {
    require(dices[diceId].owner == msg.sender);
    _;
}

modifier validDiceId(uint256 diceId) {
    require(diceId < numDices);
    _;
}

//owner can roll a dice    
function roll(uint256 diceId) public ownerOnly(diceId) validDiceId(diceId) {
        dices[diceId].state = diceState.rolling;    //set state to rolling
        dices[diceId].currentNumber = 0;    //number will become 0 while rolling
        emit rolling(diceId);   //emit rolling event
}

function stopRoll(uint256 diceId) public ownerOnly(diceId) validDiceId(diceId) {
        dices[diceId].state = diceState.stationary; //set state to stationary

        //this is not a secure randomization
        uint8 newNumber = (uint8)(block.timestamp % (dices[diceId].numberOfSides)) + 1;
        dices[diceId].currentNumber = newNumber;

        if(newNumber == dices[diceId].numberOfSides){
            dices[diceId].luckyTimes ++; 
            emit luckytimesEvent(diceId, dices[diceId].luckyTimes);
        }

        emit rolled(diceId, newNumber); //emit rolled
}

//transfer ownership to new owner
function transfer(uint256 diceId, address newOwner) public ownerOnly(diceId) validDiceId(diceId) {
    dices[diceId].prevOwner = dices[diceId].owner;
    dices[diceId].owner = newOwner;
}

function destroyDice(uint256 diceId) public ownerOnly(diceId) validDiceId(diceId) {
    msg.sender.transfer(dices[diceId].creationValue);
    dices[diceId].owner = address(0);
}

//get number of sides of dice    
function getDiceSides(uint256 diceId) public view validDiceId(diceId) returns (uint8) {
    return dices[diceId].numberOfSides;
}

//get current dice number
function getDiceNumber(uint256 diceId) public view validDiceId(diceId) returns (uint8) {
    return dices[diceId].currentNumber;
}

//get ether put in during creation
function getDiceValue(uint256 diceId) public view validDiceId(diceId) returns (uint256) {
    return dices[diceId].creationValue;
}

//get lucky times of dice
function getLuckyTimes(uint256 diceId) public view validDiceId(diceId) returns (uint8) {
    return dices[diceId].luckyTimes;
}

//get previous owner
function getPrevOwner(uint256 diceId) public view returns (address) {
    return dices[diceId].prevOwner;
}

//get owner
function getOwner(uint256 diceId) public view returns (address) {
    return dices[diceId].owner;
}

//get value
function getPrice(uint256 diceId) public view returns (uint256) {
    return dices[diceId].price;
}

//get listed status
function getListedStatus(uint256 diceId) public view returns (bool) {
    return dices[diceId].listed;
}

// //set value
// function setPrice(uint256 diceId, uint256 price) public {
//     dices[diceId].price = price;
// }

// //set listed status
// function setListedStatus(uint256 diceId, bool status) public {
//     dices[diceId].listed = status;
// }

}

Answer 1

https://blog.csdn.net/qq_30505673/article/details/84142517