對象找不到方法

Question

我試圖做一個狀態機，但它不工作。我有這個代碼至今：

function makeStateMachine() { 
    this.stateConstructors = new Object(); 
    this.currState = { 
     update : function(e) { 
      // Nothing to do here 
     }, 
     exit : function() { 
      // Nothing to declare 
     } 
    }; 
    this.nextState = null; 

    var that = this; 

    this.update = new function(e) { 
     that.currState.update(e); 

     that.changeState(); 
    }; 

    this.setNextState = new function(targetState) { 
     that.nextState = targetState; 
    }; 

    this.addState = new function(constructor, stateName) { 
     that.stateConstructors[stateName] = constructor; 
    }; 

    this.changeState = new function() { 
     if (that.nextState != null) { 
      that.currState.exit(); 
      that.currState = new that.stateConstructors[that.nextState](); 

      that.nextState = null; 
     } 
    }; 
} 

當我嘗試運行它螢火顯示此錯誤：「類型錯誤：that.changeState不是一個函數」在更新功能就行了。當我取消註釋changeState（）行時，它開始抱怨EaselJS庫不正確（我知道這是正確的，因爲它適用於我的其他項目）。有人可以幫助我嗎？這可能很簡單（就像往常一樣），但我不能發現錯誤。如果你們喜歡，我可以發佈其餘的代碼，但我認爲它不相關。

在此先感謝！

Answer 1

你應該把這些功能放在原型中。你也不應該使用= new function(...;只需使用= function(...即可。最後，你不需要that。試試這段代碼：

function makeStateMachine() { 
    this.stateConstructors = {}; 
    this.currState = { 
     update : function(e) { 
      // Nothing to do here 
     }, 
     exit : function() { 
      // Nothing to declare 
     } 
    }; 
    this.nextState = null; 
} 

makeStateMachine.prototype.update = function(e) { 
    this.currState.update(e); 
    this.changeState(); 
}; 

makeStateMachine.prototype.setNextState = function(targetState) { 
    this.nextState = targetState; 
}; 

makeStateMachine.prototype.addState = function(constructor, stateName) { 
    this.stateConstructors[stateName] = constructor; 
}; 

makeStateMachine.prototype.changeState = function() { 
    if (this.nextState != null) { 
     this.currState.exit(); 
     this.currState = new this.stateConstructors[this.nextState](); 
     this.nextState = null; 
    } 
};