我的角色怎么能向左箭头键或右键的方向跳跃？答案

【问题标题】：How can my character jump in the direction of the left arrow key or right key?我的角色怎么能向左箭头键或右键的方向跳跃？
【发布时间】：2020-06-07 04:12:37
【问题描述】：

这是我的代码。每当我按下左箭头键时，当我按下空格键时，它会停止并跳跃，并且不再向左移动（与右箭头键相同）。

    stop();
    var Gravity = 5;
    var yLimit = 400 - char.height;
var friction = .9;
var velocity = 100;
var djctr = 0;
stage.addEventListener(Event.ENTER_FRAME, entFrame);
stage.addEventListener(KeyboardEvent.KEY_DOWN, control);

function control(event:KeyboardEvent){
    if(char.y >= yLimit || djctr == 2){
        if(event.keyCode == 32 && djctr !=2){
            char.y -= velocity;
            char.x += 7;
            djctr+=2;
        }else if (event.keyCode == 32 && djctr == 2){
            char.y -= velocity * .50;
            djctr+=2;
            }

    }

    if(event.keyCode == 37){
            char.x -= 7;
    }else if(event.keyCode == 39){
            char.x += 7;
    }
    }

function entFrame(e:Event){
    char.y += Gravity;
    if(char.y >= yLimit){
        char.y = 400-char.height;
        djctr = 0;
        }
    }

【问题讨论】：

标签： actionscript-3 animation flash actionscript flash-cs5

【解决方案1】：

我为移动控制所做的是拥有两个阶段的 KeyboardEvent 侦听器（KEY_DOWN 和 KEY_UP），以及一个每帧运行的计时器。键盘事件不处理控制，它们只处理更改静态值，例如keyLeftIsDown 和keyRightIsDown（在您的情况下，您也可以在按下空格键时处理），而 Timer 侦听器是处理控制的对象。这可能是这样的：

private var keyLeftIsDown:Boolean;
private var keyRightIsDown:Boolean;

//The '60' in '1000 / 60' is the frames per second the program runs in. Change it as needed
private var movementTimer:Timer = new Timer(1000 / 60);

private function initialize():void {
    stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDown);
    stage.addEventListener(KeyboardEvent.KEY_UP, keyUp);
    timer.addEventListener(TimerEvent.TIMER, movementUpdate);
    timer.start();
}

private function keyDown(e:KeyboardEvent):void {
    if (e.keyCode == Keyboard.LEFT) {
        keyLeftIsDown = true;
    }
    else if (e.keyCode == Keyboard.RIGHT) {
        keyRightIsDown = true;
    }
    else if (e.keyCode == Keyboard.SPACE) {
        //jump code goes here
    }
}

private function keyUp(e:KeyboardEvent):void {
    if (e.keyCode == Keyboard.LEFT) {
        keyLeftIsDown = false;
    }
    else if (e.keyCode == Keyboard.RIGHT) {
        keyRightIsDown = false;
    }
}

private function movementUpdate(e:TimerEvent):void {
    if (keyLeftIsDown && !keyRightIsDown) {
        char.x -= char.speed;
    }
    else if (keyRightIsDown && !keyLeftIsDown) {
        char.x += char.speed;
    }
}

这样，即使代码正在处理跳跃，字符也会沿 x 方向移动！

【讨论】：