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I am trying to convert this Javascript to C#:

var bulletPrefab : Transform;

function Update().....

var bullet = Instantiate(bulletPrefab, GameObject.Find("gunPoint").transform.position, Quanternion.identity);
bullet.rigidbody.AddForce(transform.forward);

C#

public Transform bulletPrefab;

void Update () {
.....  

 GameObject bullet = (GameObject)Instantiate(bulletPrefab, GameObject.Find        ("gunPoint").tranform.position, Quanterion.identity);

bullet.rigidbody.AddForce(transform.forward * 2000);

When I play the game, I am getting this error "InvalidCastException: Cannot cast from source type to destination type." What am I doing wrong?

Answer 1

0

Have you tried replacing

GameObject bullet = (GameObject)Instantiate(bulletPrefab, 
    GameObject.Find("gunPoint").transform.position, Quanterion.identity);

with

Transform bullet = (Transform)Instantiate(bulletPrefab, 
    GameObject.Find("gunPoint").transform.position, Quanterion.identity);

?

If you need to get bullet as game object, you could do something like this:

Transform bulletTrans = (Transform)Instantiate(bulletPrefab, 
    GameObject.Find("gunPoint").transform.position, Quanterion.identity);
GameObject bullet = bulletTrans.gameObject;

answered Jul 30 '10 at 08:50 AM

jashan
10.3k ● 25 ● 43 ● 117

The Transform... version worked. I am a http://VB.NET programmer so I am learning the C# syntax. I know this may not be Unity related, but it has do with this Instantiate syntax. Why do you need the syntax '(Transform)' in front of Instantiate?

Thank you for the help!

Jul 30 '10 at 01:28 PM Jeff 3

When it worked for you, you may consider "accepting" the answer (click the "check" symbol left of the up/down-vote arrows). Regarding "(Transform)": That's needed because Instantiate simply returns an Object, which you need to cast to the correct type "Transform". Since Unity 2.6 some methods are available in generic versions which makes this a bit less cumbersome, e.g. GetComponent() would return "MyScript" as such, so no type-casting needed. Some more info on typecasting: http://en.csharp-online.net/Typecasting or http://en.wikipedia.org/wiki/Type_conversion

Jul 30 '10 at 05:26 PM jashan

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