如何在switch語句中使用變量*更新*

Question

我想在switch語句中使用一個變量，因爲它使播放器運動平穩。這是我的流暢播放器移動代碼。

stage.addEventListener(KeyboardEvent.KEY_DOWN, keyPressedDown); 
    stage.addEventListener(KeyboardEvent.KEY_UP, keyPressedUp); 
    stage.addEventListener(Event.ENTER_FRAME,movehero); 
    function keyPressedDown(event:KeyboardEvent){ 
if(event.keyCode==37){leftArrow = true;} 
else if (event.keyCode == 39){rightArrow=true;} 
else if(event.keyCode ==38){upArrow = true;} 
else if(event.keyCode ==40){downArrow = true;} 
} 

    function keyPressedUp(event:KeyboardEvent){ 
if(event.keyCode==37){leftArrow = false;} 
else if (event.keyCode == 39){rightArrow=false;} 
else if(event.keyCode ==38){upArrow = false;} 
else if(event.keyCode ==40){downArrow = false;} 
    } 

    function movehero(event:Event){ 
if(leftArrow){hero.x -= 10;} 
if(rightArrow){hero.x += 10;} 
if(upArrow){hero.y -= 10;} 
if(downArrow){hero.y += 10;} 
} 

我想實現它到我現有的代碼。我需要碰撞開關語句。

此代碼正常工作，但玩家移動非常呆板。

預先感謝

I am trying to acheive something like this, but this does not work 

var leftArrow:Boolean= false; 
var rightArrow:Boolean= false; 
var upArrow:Boolean= false; 
var downArrow:Boolean=false; 


    stage.addEventListener(KeyboardEvent.KEY_DOWN, keyPressedDown); 
    stage.addEventListener(KeyboardEvent.KEY_UP, keyPressedUp); 
    stage.addEventListener(Event.ENTER_FRAME,movehero); 

    function keyPressedDown(event:KeyboardEvent){ 
if(event.keyCode==37){leftArrow = true;} 
else if (event.keyCode == 39){rightArrow=true;} 
else if(event.keyCode ==38){upArrow = true;} 
else if(event.keyCode ==40){downArrow = true;} 
} 

    function keyPressedUp(event:KeyboardEvent){ 
if(event.keyCode==37){leftArrow = false;} 
else if (event.keyCode == 39){rightArrow=false;} 
else if(event.keyCode ==38){upArrow = false;} 
else if(event.keyCode ==40){downArrow = false;} 
    } 

    function movehero(event:Event){ 

switch(event){ 
    case leftArrow: 
    hero.x -=10; 
    break; 

    case rightArrow: 
    hero.x +=10; 
    break; 

    case upArrow: 
    hero.y -=10; 
    break; 

    case downArrow: 
    hero.y += 10; 
    break; 

    default : 
    break; 
} 

}

Answer 1

stage.addEventListener(KeyboardEvent.KEY_DOWN, keyPressedDown); 
stage.addEventListener(KeyboardEvent.KEY_UP, keyPressedUp); 
stage.addEventListener(Event.ENTER_FRAME,movehero); 

function keyPressedDown(event:KeyboardEvent) 
{ 
    if(event.keyCode==37) leftArrow = true; 
    else if(event.keyCode == 39) rightArrow = true; 
    else if(event.keyCode ==38) upArrow = true; 
    else if(event.keyCode ==40) downArrow = true; 
} 

function keyPressedUp(event:KeyboardEvent) 
{ 
    if(event.keyCode == 37) leftArrow = false; 
    else if (event.keyCode == 39) rightArrow = false; 
    else if(event.keyCode == 38) upArrow = false; 
    else if(event.keyCode == 40) downArrow = false; 
} 

function movehero(event:Event) 
{ 
    switch(true) 
    { 
     case (leftArrow): 
      hero.x -=10; 
      break; 

     case (rightArrow): 
      hero.x +=10; 
      break; 

     case (upArrow) : 
      hero.y -=10; 
      break; 

     case (downArrow): 
      hero.y += 10; 
      break; 
    } 
} 

Answer 2

這是一個良好的圖案使用鍵盤時設置方向的布爾型變量，。試着功能movehero的驗證碼

function movehero(event:Event) 
{  
     if (this.leftArrow): 
      hero.x -= 10 ; 

     if (this.rightArrow) 
      hero.x += 10 ; 

     if (this.upArrow) 
      hero.y -= 10 ; 

     if (this.downArrow) 
      hero.y += 10 ; 
} 

注意：如果你真的想使你的英雄平滑移動，增加遊戲的幀速率，並減慢速度。所以，英雄會執行MORE SMALL步驟，看起來是平穩的動作，而不是更新了，但是BIG步驟。

因此，而不是增加+10,使其+2和增加幀率。 30-40 fps對於平穩移動來說足夠了。

祝你好運，希望它有所幫助:)