C#•3y ago

InvalidCastException Specified cast is not valid.

public void DestroyCities() //102
    { //103
        foreach(GameObject go in transform) //104
        { //105
            do {
                StartCoroutine(DestroyFastly(go));
            } while(go != null);
        }
    }

public void DestroyCities() //102
    { //103
        foreach(GameObject go in transform) //104
        { //105
            do {
                StartCoroutine(DestroyFastly(go));
            } while(go != null);
        }
    }

Why is this happening

29 Replies

333fred•3y ago

What is the type of transform

ZenternionOP•3y ago

https://docs.unity3d.com/ScriptReference/Transform.html

Tvde1•3y ago

Do you have the stack trace (and line number) where the error ocurred?

ZenternionOP•3y ago

line 104

Tvde1•3y ago

Which line is that in your code block

ZenternionOP•3y ago

foreach(GameObject go in transform)

Angius•3y ago

Well, a Transform is not a GameObject from what I see

ZenternionOP•3y ago

yea

Angius•3y ago

So that's the issue

ZenternionOP•3y ago

public void DestroyCities()
    {
        for (int i = 0; i < transform.childCount; i++) 
        {
            GameObject go = transform.GetChild(i).gameObject;

public void DestroyCities()
    {
        for (int i = 0; i < transform.childCount; i++) 
        {
            GameObject go = transform.GetChild(i).gameObject;

found this

333fred•3y ago

Man, unity's docs are hard to read

ZenternionOP•3y ago

on a phone

333fred•3y ago

It doesn't document what GetEnumerator() returns at all Period Can you tell me what transform.GetEnumerator() returns? Because their online docs are actually bad enough that I can't find this out

ZenternionOP•3y ago

I cant find anything on the docs

333fred•3y ago

Yes, that's why I'm asking you to try it in your code and tell me what it returns

ZenternionOP•3y ago

333fred•3y ago

Like, just do var x = transform.GetEnumerator();, then hover over var and tell me what it says the type is

ZenternionOP•3y ago

Transform

333fred•3y ago

Screenshot?

ZenternionOP•3y ago

I searched it up visual studio code or community

333fred•3y ago

Whatever you're using Sorry, but I don't believe you found the correct answer to the question by searching. That's why I asked you for a screenshot. Mainly because I'm about 80% certain that GetEnumerator() is going to return IEnumerator And I'm trying to confirm that's true before I give you the long-winded explanation of what's going on with your code

ZenternionOP•3y ago

why do you want to use getenumerator

333fred•3y ago

Because that's what foreach is using Please, just tell me what type GetEnumerator() is returning

ZenternionOP•3y ago

for (int i = 0; i < transform.childCount; i++)

for (int i = 0; i < transform.childCount; i++)

333fred•3y ago

Stop

ZenternionOP•3y ago

im getting nothing

333fred•3y ago

Just tell me what type GetEnumerator() is returning so I can confirm why you're getting that exception You're not getting nothing Unless you haven't tried it

ZenternionOP•3y ago

from hovering over the var

333fred•3y ago

Do you have your development environment correctly set up? Do you get intellisense? Alright, well, assuming you ever figure out what GetEnumerator() is returning, here's what's (almost certainly) happening: foreach (V v in x) is fancy compiler speak for this:

{
    E e = x.GetEnumerator();
    try
    {
        while (e.MoveNext())
        {
            V v = (V)e.Current;
            // Body of your foreach
        }
    }
    finally
    {
        ... // Dispose e
    }
}

{
    E e = x.GetEnumerator();
    try
    {
        while (e.MoveNext())
        {
            V v = (V)e.Current;
            // Body of your foreach
        }
    }
    finally
    {
        ... // Dispose e
    }
}

If e.Current (ie, the return type of transform.GetEnumerator().Current is an object, it will automatically and silently be cast to the type you said in the foreach loop, GameObject in this case. This is an unfortunate behavior from C# 1.0 that pretty much no one runs into anymore because generic collections are much better, but I'm guessing that Unity isn't using a generic collection here, just IEnumerator.

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InvalidCastException Specified cast is not valid.