Problem with Null Reference Exception??

Questions & Answers
1

So i have a script that activates a GUI when you press “e” on it. It’s meant to pause the game when you are writing a “secret password” on the GUI. For this, i did the same that I have done with another script, I lock the camera, the movement of the character, the hability to turn the flash light on/off, etc.
The problem only one thing is working, when i press “e” it gets displayed, but all the other variables that i want to transform into “false” are not responding…
Here is the error:

NullReferenceException: Object reference not set to an instance of an object
SafeLockOnE.Update () (at Assets/SafeLockOnE.js:38)

Here is the Script:

var range: float = 5; 
private var hit: RaycastHit;
var SafeLockMeca : SafeLock;

var lookAround01 : MouseLook;
var lookAround02 : MouseLook;
var charMotor : CharacterMotor;
var charMotor2 : FPSWalkerEnhaced;
var FlashlightHide : FlashLight;
var HideCursor : HideMouseCursor;

function Start ()  
{
	SafeLockMeca = gameObject.GetComponent(SafeLock);
	

    lookAround01 = gameObject.GetComponent(MouseLook);
    lookAround02 = GameObject.Find("MainCamera").GetComponent(MouseLook);
    charMotor = gameObject.GetComponent(CharacterMotor);
    charMotor2 = gameObject.GetComponent(FPSWalkerEnhaced);
    FlashlightHide = GameObject.Find("FlashLight").GetComponent(FlashLight);
    HideCursor = GameObject.Find("Player").GetComponent(HideMouseCursor);
 
       SafeLockMeca.enabled = false;
 
}
 
 
 
function Update(){
 
  if (Input.GetKeyDown("e")){
    var ray = Camera.main.ViewportPointToRay(Vector3(0.5,0.5,0));
    if (Physics.Raycast(ray, hit, range)){
        SafeLockMeca.enabled = true;
 
        lookAround01.enabled = false;
        lookAround02.enabled = false;
        charMotor.enabled = false;
        charMotor2.enabled = false;
        FlashlightHide.enabled = false;
        HideCursor.enabled = false;
       
                    
  if (Input.GetKeyDown("KeyCode.Escape")){

        SafeLockMeca.enabled = false;


}
}
}
}

Tips:
If i delete line 38, and everything that it’s related to it, the next line does’nt work either, so only “SafeLockMeca.enabled = true;” it’s working, from lookAround01.enabled = false; to HideCursor.enabled = false; is not working…:frowning:

PS:

  1. Also i don’t know why but i discovered that the GUI with the password gets displayed also if i press “e” near any object with a collider…

  2. I would also like if someone can show me a way to close the GUI when i press “ESC”

2

Which object is this script attached to? This code could get the right script instances only if all of them (including this script) were attached to the same object - the player, in this case. If this script (and SafeLock) are attached to a different object than the player, Start should be like this:

function Start ()  
{
    SafeLockMeca = GetComponent(SafeLock); // get SafeLock from this object
    var player = GameObject.Find("Player"); // get other scripts from the player
    lookAround01 = player.GetComponent(MouseLook);
    lookAround02 = Camera.main.GetComponent(MouseLook);
    charMotor = player.GetComponent(CharacterMotor);
    charMotor2 = player.GetComponent(FPSWalkerEnhaced);
    HideCursor = player.GetComponent(HideMouseCursor);
    // be careful: if there's more than one flashlight object
    // in scene, this line may return the wrong instance:
    FlashlightHide = GameObject.Find("FlashLight").GetComponent(FlashLight);
    SafeLockMeca.enabled = false;
}

And the Raycast won’t do what you expect, whatever it is: it checks for key E whenever any collider is in the middle of the screen and closer enough to the camera. What do you wanna do? Sense E when the mouse is over an existing GUIText or GUITexture? Or when the mouse is over the area where the GUI password should appear?

EDITED: Ok, so you want to enable the GUI code when the player is inside the trigger and E is pressed. You could use OnTriggerStay, but it’s more efficient to have a boolean that tells whether the player has entered/exited the trigger. You should also monitor the current GUI state, and enable/disable the other scripts only when the GUI gets disabled/enabled - like this:

private var inTrigger = false; // is player inside trigger?

function OnTriggerEnter(other: Collider){
  if (other.CompareTag("Player")) inTrigger = true;
}

function OnTriggerExit(other: Collider){
  if (other.CompareTag("Player")) inTrigger = false;
}

private var guiEnabled = false; // current gui state

function Update(){
  // if inside trigger and E pressed...
  if (inTrigger && Input.GetKey("e")){
    SafeLockMeca.enabled = true; // enable gui
  }
  // ESC disables gui
  if (Input.GetKey("escape")){ 
    SafeLockMeca.enabled = false;
  }
  // if GUI changed its enabled state...
  if (SafeLockMeca.enabled != guiEnabled){
    guiEnabled = SafeLockMeca.enabled; // update guiEnabled
    // disable/enable other scripts accordingly:
    lookAround01.enabled = !guiEnabled;
    lookAround02.enabled = !guiEnabled;
    charMotor.enabled = !guiEnabled;
    charMotor2.enabled = !guiEnabled;
    FlashlightHide.enabled = !guiEnabled;
    HideCursor.enabled = !guiEnabled;
  }    
}

NOTE: In order to close the GUI when the correct password has been entered, just make SafeLock disable itself - for instance (SafeLock script):

function OnGUI(){
  password = GUI.TextField (Rect (10, 10, 200, 20), password, 25);
  if (password == "cheat123"){
    enabled = false; // disable itself
  }
}

The script in the trigger detects any change in SafeLock.enabled property and disables/enables the other scripts as needed.