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Object reference not set to an instance of an object

by Stuart Walton · in Torque X 2D · 05/08/2008 (10:49 am) · 4 replies

Im just trying to add life icons to the game im working on based on the Blaster tutorial code for an assignment.

Using code from Spaceshooter that generates the life icon sprites implimented into my game.cs im getting an error on line:

_life1 = (T2DSceneObject)(TorqueObjectDatabase.Instance.FindObject("PlayerShipIcon") as T2DStaticSprite).Clone();

The error is:

NullReferenceException was unhandled
Object reference not set to an instance of an object.

What does this error mean? i also got it yesterday when trying to add sound to the game.

What do i need to do to correct this error?
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Torque 3D Owner Jonathon Stevens
#1
05/08/2008 (10:53 am)
The error means you are trying to access/reference an object that doesn't exist. For instance, if PlayerShipIcon doesn't exist, then _life1 would be null because nothing would be written to it.

You need to step through the code to see what the issue is and get more details.

Torque Owner Stuart Walton
#2
05/08/2008 (11:35 am)
Cheers fixed it by creating an object in the scene called PlayerShipIcon

I thought origionaly it was trying to find something that didnt exist within the code

Torque Owner Russell Bishop
Default Studio Name
#3
05/08/2008 (6:50 pm)
Technically it isn't that _life1 is null, but that this:

(T2DSceneObject)(TorqueObjectDatabase.Instance.FindObject("PlayerShipIcon") as T2DStaticSprite)

results in a null value, which you are then trying to call the Clone() method on, which (for obvious reasons) fails. Also, there is no reason to do a double cast. the (type) cast operator and the as keyword do the same thing, so just do this:

(TorqueObjectDatabase.Instance.FindObject("PlayerShipIcon") as T2DSceneObject)

Torque 3D Owner Jonathon Stevens
#4
05/09/2008 (8:01 am)
@Russell - I was trying to laymen term it for him since he obviously isn't a strong programmer based on his initial post =P