为什么我不能访问其他类的公共变量？

Question

我想在我的游戏文档类中定义我的变量，然后在我的Movement类中使用其中的一些变量。但是，当我在运动类中使用这些变量时，我收到了大量的编译错误，说它们都是未定义的。

因此我的问题是，为什么我的公共变量不会传递给我的其他类？我通过做import game;来导入课程，所以这让我感到困惑。我可能只是做错了，但非常感谢帮助。

时间轴

addChild((new Movement)); 

游戏文档类

package 
{ 
    import flash.display.MovieClip; 
    import flash.utils.Timer; 
    import flash.events.TimerEvent; 

    public class game extends MovieClip 
    { 
     public var area1:Boolean = true; 
     public var area2:Boolean = false; 
     public var area3:Boolean = false; 

     public var player1:Boolean = true; 

     public var playerPosKeeper_mc:MovieClip = new mc_PlayerPosKeeper(); 

     public var up_dpad:MovieClip = new dpad_Up(); 
     public var down_dpad:MovieClip = new dpad_Down(); 
     public var left_dpad:MovieClip = new dpad_Left(); 
     public var right_dpad:MovieClip = new dpad_Right(); 
     public var menu_dpad:MovieClip = new dpad_Menu(); 
     public var run_dpad:MovieClip = new dpad_Menu(); 

     public var barrierRoof1_game:MovieClip = new game_BarrierRoof(); 
     public var barrierRoof2_game:MovieClip = new game_BarrierRoof(); 
     public var barrierSide1_game:MovieClip = new game_BarrierSide(); 
     public var barrierSide2_game:MovieClip = new game_BarrierSide(); 

     public function game() 
     { 
      trace("SUCCESS | Constructed Game Class"); 

     } 
    } 
} 

运动类

package 
{ 
    import game; 
    import flash.display.Stage; 
    import flash.display.MovieClip; 
    import flash.events.Event; 
    import flash.events.TouchEvent; 
    import flash.net.dns.AAAARecord; 
    import flash.ui.Multitouch; 
    import flash.ui.MultitouchInputMode; 


    public class Movement extends MovieClip 
    { 
     var inMotion:Boolean = false; 

     public function Movement() 
     { 
      trace("SUCCESS | Constructed Movement Class"); 

      addChild(playerPosKeeper_mc); 
      playerPosKeeper_mc.x = 384; 
      playerPosKeeper_mc.y = 46; 

      addChild(up_dpad); 
      up_dpad.x = 55; 
      up_dpad.y = 336; 

      addChild(down_dpad); 
      down_dpad.x = 57; 
      down_dpad.y = 432; 

      addChild(left_dpad); 
      left_dpad.x = 19; 
      left_dpad.y = 372; 

      addChild(right_dpad); 
      right_dpad.x = 118; 
      right_dpad.y = 372; 

      addChild(menu_dpad); 
      menu_dpad.x = 61; 
      menu_dpad.y = 377; 

      addChild(run_dpad); 
      run_dpad.x = 684; 
      run_dpad.y = 369; 

      addChild(barrierRoof1_game); 
      barrierRoof1_game.x = 0; 
      barrierRoof1_game.y = 0; 

      addChild(barrierRoof2_game); 
      barrierRoof2_game.x = 0; 
      barrierRoof2_game.y = 470; 

      addChild(barrierSide1_game); 
      barrierSide1_game.x = 0; 
      barrierSide1_game.y = 0; 

      addChild(barrierSide2_game); 
      barrierSide2_game.x = 790; 
      barrierSide2_game.y = 0; 

      Multitouch.inputMode = MultitouchInputMode.TOUCH_POINT; 

      up_dpad.addEventListener(TouchEvent.TOUCH_BEGIN, moveUpTouchBEGIN); 
      up_dpad.addEventListener(TouchEvent.TOUCH_END, moveUpTouchEND); 

     } 
     public function moveUpTouchBEGIN(e:TouchEvent):void 
     { 
      trace("Touch Began") 
     } 

     public function moveUpTouchEND(e:TouchEvent):void 
     { 
      trace("Touch Ended") 
     } 
    } 

} 

Answer 1

你困惑因为“公共”并不意味着“全球”。声明变量为公共意味着您想授予对任何实体的访问权限，因为实体知道，其中该变量是。

让我们看看你有什么。

• 顶部展示对象：舞台。
• 主要时间表：游戏是一个阶段的孩子。
• MovieClip up_dpad，down_dpad等等，都是游戏实例的字段。
• 运动：实例是游戏的一个孩子。

在运动中，您尝试访问up_dpad和其他人，但他们保留为游戏实例的字段，并且与Movement实例无关。这就是为什么他们不在运动的地址范围内。

所以，如果你想把这些变量声明为游戏场，你需要以正确的方式从运动中解决它们。

忘记时间表。在游戏中（为求的缘故永远不会调用类的小写，除非在枪口下），这是，我认为，一个根文档类：

public function Game() 
    { 
     trace("SUCCESS | Constructed Game Class"); 

     // Pass reference to this instance to the constructor. 
     var aMove:Movement = new Movement(this); 

     // Add it as a child. 
     addChild(aMove); 
    } 

运动：

public function Movement(main:Game) 
    { 
     trace("SUCCESS | Constructed Movement Class"); 

     // Access variables inside Game instance via given reference. 
     addChild(main.playerPosKeeper_mc); 
     main.playerPosKeeper_mc.x = 384; 
     main.playerPosKeeper_mc.y = 46; 

     // ...and so on 
    } 

这些都是基础知识面向对象编程。如果你想访问对象内的任何东西，你需要先访问对象。