Question

有人可以告诉我哪里出错了吗？我一直在看这个一个小时，我不明白为什么不是这个.x未定义。

它在某处：

var canvas, canvasContext;

var blueCar = new carClass();

window.onload = function() {
    canvas = document.getElementById('gameCanvas');
    canvasContext = canvas.getContext('2d');

    colorRect(0,0,canvas.width,canvas.height,'red');
    colorText("       LOADING...",canvas.width/3,canvas.height/2,'white',"30px Arial")

    loadImages();
}

function imageLoadingDoneSoStartGame(){
    var framesPerSecond = 30;
    setInterval(updateAll, 1000/framesPerSecond);
    setUpInput();
    bluecar.reset();
}

function updateAll() {
    moveAll();
    drawAll();
}

function moveAll() {
    blueCar.move();
    carTrackHandling();
}

function drawAll() {
    console.log(bluecar.x);
    drawTracks();
    blueCar.draw(blueCar);
}

这里：

function carClass(){

    this.x = 75;
    this.y = 75;
    this.ang = 0;
    this.speed = 0;

    //reset car 1
    this.reset = function() {
        for(var eachRow=0;eachRow<TRACK_ROWS;eachRow++) {
            for(var eachCol=0;eachCol<TRACK_COLS;eachCol++) {

                var arrayIndex = rowColToArrayIndex(eachCol, eachRow); 

                if(trackGrid[arrayIndex] == TRACK_BLUE_START) {

                    trackGrid[arrayIndex] = TRACK_ROAD;
                    this.ang = -Math.PI/2;
                    this.x= eachCol * TRACK_W + TRACK_W/2;
                    this.y= eachRow * TRACK_H + TRACK_H/2;
                }//end of player start if
            }//end if col for
        }//end if row for
    }//end of car reser function

//move car 1
    this.move = function() {

        this.speed *= GROUND_SPEED_DECAY_MULT

        if(keyHeld_Gas){
            this.speed += DRIVE_POWER;
        }
        if(keyHeld_Reverse){
            this.speed -= REVERSE_POWER;
        }
        if(Math.abs(this.speed) > MIN_SPEED_TO_TURN){
            if(keyHeld_TurnLeft){
                this.ang -= TURN_RATE;
            }
            if(keyHeld_TurnRight){
                this.ang += TURN_RATE;
            }
        }
        this.x += Math.cos(this.ang) * this.speed;
        this.y += Math.sin(this.ang) * this.speed;

       // carAng += 0.02
    }

    this.draw = function(){
        drawBitmapCenteredWithRoatation(blueCarPic, this.x,this.y, this.ang);
    }
}

或在这里：

    function carTrackHandling(wichCar) {
    var carTrackCol = Math.floor(wichCar.x / TRACK_W);
    var carTrackRow = Math.floor(wichCar.y / TRACK_H);
    var trackIndexUnderCar = rowColToArrayIndex(carTrackCol, carTrackRow);

    if(carTrackCol >= 0 && carTrackCol < TRACK_COLS &&
        carTrackRow >= 0 && carTrackRow < TRACK_ROWS) {

        if(isObstacleAtColRow( carTrackCol,carTrackRow )) {

            //fixes bug
            wichCar.x -= Math.cos(wichCar.ang) * wichCar.speed;
            wichCar.y -= Math.sin(wichCar.ang) * wichCar.speed;

            //reduse speed and bounces car when hits a wall
            wichCar.speed*= -0.5;

        } // end of track found
    } // end of valid col and row
} // end of carTrackHandling func

我得到的确切错误是：

其中Track.js：是：var carTrackCol = Math.floor（wichCar.x / TRACK_W）;

Uncaught TypeError: Cannot read property 'x' of undefined
at carTrackHandling (Track.js:34)
at moveAll (Main.js:29)
at updateAll (Main.js:23)

任何帮助都会被发现，并告诉我我做错了什么，谢谢。

Answer 1

您的功能定义为function carTrackHandling(wichCar) {。它需要一个参数，这是你想要处理的汽车（我假设）。

如果您使用moveAll()功能，则不会将汽车传递给您的功能。当您的函数尝试访问x whichCar时，它会抛出错误，因为它未定义（因为它没有通过任何汽车）。如下图所示，将您想要处理的汽车通过moveAll()功能：

carTrackHandling();

应该是：

blueCar.move();
carTrackHandling(blueCar);

Answer 2

看起来你没有将任何内容传递给function moveAll() { blueCar.move(); carTrackHandling(); }并且期望传递一个对象。

看起来你在这里没有参数调用它。

whichCar

然后，当您使用此函数时function carTrackHandling(wichCar) { var carTrackCol = Math.floor(wichCar.x / TRACK_W); ... }将被定义为导致您看到的错误。


model.outputs[0].save('CNTK_model2.pb')

未捕获类型错误：无法读取属性＆＃39; x＆＃39;未定义的

2 个答案: