前端之家

  1. 首页
  2. 问答

未捕获（承诺）TypeError：无法读取未定义的属性“ 0”

• 问答

我的应用程序中的Promise存在问题。有时我打开项目会一切正常，但有时会遇到以下问题：

未捕获（承诺）TypeError：无法读取未定义的属性“ 0”

这是我在p5中的代码



var flag = false;
var flag2 = false;


function preload() {

   // let url = '/Boards/Json';
    json = loadJSON('/Boards/Json');
    flag = true;
    flag2 = true;
}


window.fields = [];
window.properites = [];
window.categories = [];
window.newtile = [];
window.players = [];
for (var i = 0; i < 40; i++) {
    window.fields[i] = { id_Field: 0,nameOfField2: ' ',TypeOfField: 0,Price: 0 }
}
for (i = 0; i < 28; i++) {
    window.properites[i] = { id_Property: 0,type_Of_Property: 0,owner_FK: 0,field_Fk: 0,category_FK: 0 }
}
for (i = 0; i < 9; i++) {
    window.categories[i] = { id_Category: 0,Name: '',entry_Value: 0,upgrade_Cost: 0 }
}

for (i = 0; i < 4; i++) {
    window.players[i] = {id_Player:0,NameOfPlayer:'',AmountOfCash:0,PositionPlayer:0}
}
window.all_fields = [];

var tileRowUp = [];
var tileColLeft = [];
var tileColRight = [];
var tileRowdown = [];
var widthheight = 880;
let initialPosX = 225;
let initialPosY = 225;
var PlayerArray = [];


var d = 0;
var m = 0;
var n = 0;
var b = 0;

var counters = [];

function setup() {
    createCanvas(1800,1800);
    background(255);

    for (var i = 0; i < 3; i++) {

        for (var k = 0; k < 3; k++) {
            var x = (i + 4) * initialPosX;
            var y = (k) * initialPosY;
            newtile[m] = new category_class('',x,y,150,''); 

            m = m + 1; 
        }
    }
    for (var i = 0; i < 2; i++) {
        for (k = 0; k < 2; k++) {
            var x = (i + 5) * 200;
            var y = (k+6) * 110;
            PlayerArray[b] = new Player(x,100,'',0);
            b = b + 1;
        }
    }


    if (flag2) {
        for (var i = 0; i < 40; i++) {
            fields[i].nameOfField2 = json.field_list[i].name;

            fields[i].id_Field = json.field_list[i].id_field;
            fields[i].TypeOfField = json.field_list[i].field_type;

        }
        for (var i = 0; i < 4; i++) {
            players[i].id_Player = json.player_list[i].id_player;
            players[i].NameOfPlayer = json.player_list[i].name;
            players[i].AmountOfCash = json.player_list[i].amount_of_cash;
            players[i].PositionPlayer = json.player_list[i].position;

        }
        for (var i = 0; i < 28; i++) {
            properites[i].id_Property = json.property_list[i].id_property;
            properites[i].type_Of_Property = json.property_list[i].type_of_property;
            properites[i].owner_FK = json.property_list[i].ownerFK;
            properites[i].field_Fk = json.property_list[i].fieldFK;
            properites[i].category_FK = json.property_list[i].categoryFK;


        }
        for (var i = 0; i < 9; i++) {

            categories[i].id_Category = json.category_list[i].id_category;
            categories[i].Name = json.category_list[i].name;
            categories[i].entry_Value = json.category_list[i].entry_value;
            categories[i].upgrade_Cost = json.category_list[i].upgrade_cost;

        }

        for (var i = 0; i < 4; i++) {
            PlayerArray[i].id_Player = players[i].id_Player;
            PlayerArray[i].Name_Player = players[i].NameOfPlayer;
            PlayerArray[i].amount_Of_Cash = players[i].AmountOfCash;
            PlayerArray[i].Position = 0;
        }
        flag2 = false;
    }
    for (var i = 0; i < 2; i++) {
        for (var z = 0; z < 2; z++) {
            var x = (i + 1) * 20;
            var y = (z + 2) * 20;
            counters[d] = new Counter(x,10,0);
            d = d + 1;
        }
    }
    for (var i = 0; i < 4; i++) {
        counters[i].id_Player = players[i].id_Player;
        counters[i].Name_Player = players[i].NameOfPlayer;
        counters[i].amount_Of_Cash = players[i].AmountOfCash;
        counters[i].Position = players[i].PositionPlayer;
        counters[0].Color = 'RED';
        counters[1].Color = 'BLUE';
        counters[2].Color = 'YELLOW';
        counters[3].Color = 'BLACK';

    }

}

var k = 11;
var x = 80;
var pom = 0;
var pom1 = 0;
var m2 = 0;   

var clicked = 0;


function draw() {



    //for (var i = 0; i < 4; i++) {
    //    PlayerArray[i].id_Player = players[i].id_Player;
    //    PlayerArray[i].Name_Player = players[i].NameOfPlayer;
    //    PlayerArray[i].amount_Of_Cash = players[i].AmountOfCash;
    //    PlayerArray[i].Position = players[i].PositionPlayer;
    //}
    for (var i = 0; i < 4; i++) {
        counters[i].id_Player = players[i].id_Player;
        counters[i].Name_Player = players[i].NameOfPlayer;
        counters[i].amount_Of_Cash = players[i].AmountOfCash;
        counters[i].Position = players[i].PositionPlayer;
        counters[0].Color = 'RED';
        counters[1].Color = 'BLUE';
        counters[2].Color = 'YELLOW';
        counters[3].Color = 'BLACK';

    }

    for (var k = 0; k < 9; k++) {
        var a = 0;
        newtile[k].nameOfCategory = categories[k].Name;
        for (var z = 0; z < 28; z++) {
            if (categories[k].id_Category == properites[z].category_FK) {
                for (var m = 0; m < 40; m++) {
                    if (properites[z].field_Fk == fields[m].id_Field)
                        if (a <= 4) {
                            newtile[k].property1[a] = fields[m].nameOfField2;
                                a = a + 1;
                        }


                }
            }

        }


    }

    for (var i = 0; i < 11; i++) {

        var posX = map(i,11,widthheight);

        tileRowUp[i] = new Tile(posX,fields[i].id_Field,fields[i].nameOfField2,fields[i].TypeOfField);

    }

    var k = 10;
    for (var i = 0; i < 11; i++) {

        var posX = map(i,widthheight);
        if (k < 21) {
            tileColRight[i] = new Tile(widthheight - x,posX,fields[k].id_Field,fields[k].nameOfField2,fields[k].TypeOfField);
            k = k + 1;

        }
    }
    var k2 = 30;
    for (var i = 0; i < 11; i++) {

        var posX2 = map(i,widthheight);
        if (k2 >= 21) {
            tileRowdown[i] = new Tile(posX2,widthheight - x,fields[k2].id_Field,fields[k2].nameOfField2,fields[k2].TypeOfField);
            k2 = k2 - 1;
        }
    }
    var k3 = 39;
    for (var i = 1; i < 11; i++) {

        var posY = map(i,widthheight);

        if (k3 >= 30) {
            tileColLeft[i] = new Tile(0,posY,fields[k3].id_Field,fields[k3].nameOfField2,fields[k3].TypeOfField);
            k3 = k3 - 1;
        }

    }



    if (flag) {


        while (pom < 40) {
            all_fields[pom] = new Tile(0,0);
            pom = pom + 1;
        }


        for (var i = 0; i < 11; i++) {


            all_fields.splice(pom1,1,tileRowUp[i]);
            pom1 = pom1 + 1;


        }


        for (var i = 1; i < 11; i++) {

            all_fields.splice(pom1,tileColRight[i]);
            pom1 = pom1 + 1;

        }
        for (var i = 9; i >= 0; i--) {

            all_fields.splice(pom1,tileRowdown[i]);
            pom1 = pom1 + 1;

        }
        for (var i = 9; i >= 1; i--) {

            all_fields.splice(pom1,tileColLeft[i]);
            pom1 = pom1 + 1;

        }

        for (var i = 0; i < 40; i++) {
            if (all_fields[i].TypeOfField == 4) {
                for (var k = 0; k < 28; k++) {
                    if (all_fields[i].id_Field == properites[k].field_Fk) {
                        for (var c = 0; c < 9; c++) {
                            if (properites[k].category_FK == categories[c].id_Category) {
                                all_fields[i].Price = categories[c].entry_Value;
                                break;

                            }

                        }
                    }
                }
            }
        }
        for (var i = 0; i < 40; i++) {
            all_fields[i].show();
        }
        for (var i = 0; i < 9; i++) {
            newtile[i].show_tiles();
        }
        for (var i = 0; i < 4; i++) {
            PlayerArray[i].show_player();
        }
        for (var i = 0; i < 4; i++) {

            counters[i].show_counter(counters[i].Color);
        }
        var pom = 0;
        let bClick = document.getElementById("roll");
        bClick.onclick = function () {


            dice_roll();

           movePlayer();

            //data();

        }

        var some;
        var url = "/Boards/Game";
        function dice_roll() {
            let generated_numbers = this.numbers = Math.floor(Math.random() * 12) + 1;
            let data = { numbers: generated_numbers,decision_value: 999 };
            let url2;
            pom = 1;
            httpPost(url,'json',data,dataPosted,dataError,function () {
                makesom(url2 = '/Boards/Json',json2 = loadJSON(url2),function () {
                    isready(some,function () {

                        for (var i = 0; i < 4; i++) {
                            PlayerArray[i].id_Player = json2.player_list[i].id_player;
                            PlayerArray[i].Name_Player = json2.player_list[i].name;
                            PlayerArray[i].Position = json2.player_list[i].position;

                        }
                        for (var i = 0; i < 4; i++) {
                            PlayerArray[i].show_player();
                        }
                        movePlayer();
                    });
                });
            });
        }

        flag = false;
    }





}


var current_player = 1;

function movePlayer() {

    let url_ = '/Boards/Json';
    json3 = loadJSON(url_);
    var pom = 0;
        for (var i = 0; i < 4; i++) {
            if (current_player > 4) current_player = 1;
            for (var c = 0; c < 40; c++) {
                if (counters[i].id_Player == current_player && counters[i].Position == all_fields[c].id_Field) {
                    if (counters[i].x < 800) {
                        counters[i].x = all_fields[c].x + 10;
                    }
                    else {
                        counters[i].y = all_fields[i].y + 10;
                    }
                    counters[i].show_counter(counters[i].Color);
                    current_player += 1;
                    pom = 1;
                    break;
                }
            }
            if (pom == 1) break;

        }

    }




function makesom() {
let url2 = '/Boards/Json';
        json2 = loadJSON(url2,isready);
}

function isEmpty(obj) {
    for (var prop in obj) {
        if (obj.hasOwnProperty(prop))
            return false;
    }

    return true;
}




   // httpDo(url,'POST',dataError);


function dataPosted(result) {
    console.log(result);
}

function dataError(err) {
    console.log(err);
}

function get_data() {

    let url2 = '/Boards/Json';
    json2 = loadJSON(url2,isready);
}


function isready() {

    for (var i = 0; i < 4; i++) {
        PlayerArray[i].id_Player = json2.player_list[i].id_player;
        PlayerArray[i].Name_Player = json2.player_list[i].name;
        PlayerArray[i].Position = json2.player_list[i].position;

    }
    for (var i = 0; i < 4; i++) {
        PlayerArray[i].show_player();
    }
}

我有一个preload（）函数，该函数应使setup（）等待直到其中的所有加载调用完成。我认为我在这里做错了，因为看起来preload（）在setup（）之前没有结束，或者我只是错误地解释了这个错误？有人知道我的代码出错了吗？ ，我在这里找不到什么问题:(

jksaghefi 回答：未捕获（承诺）TypeError：无法读取未定义的属性“ 0”
暂时没有好的解决方案，如果你有好的解决方案，请发邮件至：iooj@foxmail.com
javascriptp5.jspreload
本文链接：https://www.f2er.com/3044747.html

大家都在问