stride3d/stride · error · InvalidOperationException

GetObject can only be used for Permutation or Object keys

Error message

GetObject can only be used for Permutation or Object keys

What it means

GetObject, like SetObject, is restricted to Permutation or Object keys because object lookups read from the ObjectValues reference array. Typed keys store data elsewhere, so requesting them via GetObject throws InvalidOperationException.

Solutions

Filter keys by Type == ParameterKeyType.Permutation || Type == ParameterKeyType.Object before calling GetObject
Use typed Get<T> for typed keys
Note GetObject returns null (rather than throwing) when the key is valid but unset — only the key-type mismatch throws

Example fix

// before
var v = collection.GetObject(someFloatKey);
// after
var v = someFloatKey.Type == ParameterKeyType.Permutation || someFloatKey.Type == ParameterKeyType.Object
    ? collection.GetObject(someFloatKey)
    : collection.Get(someFloatKey);

Defensive patterns

Strategy: validation

Validate before calling

object v = key.Type is ParameterKeyType.Permutation or ParameterKeyType.Object
    ? collection.GetObject(key)
    : null;

Type guard

bool CanGetObject(ParameterKey key) => key.Type is ParameterKeyType.Permutation or ParameterKeyType.Object;

Try / catch

try { v = collection.GetObject(key); } catch (InvalidOperationException) { v = null; /* handle typed keys via Get<T> */ }

Prevention

When enumerating all keys, filter by key.Type before GetObject
Remember GetObject legitimately returns null for valid-but-unset keys — only the type check throws

When it happens

Trigger: Calling GetObject with a key whose Type is not Permutation or Object.

Common situations: Debug/dump code enumerating keys and calling GetObject on every one; reflection-based serialization of parameter collections.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/0f16d6d83bdde8ea. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Foundation/Rendering/ParameterCollection.cs:513

        {
            if (key.Type != ParameterKeyType.Permutation && key.Type != ParameterKeyType.Object)
                throw new InvalidOperationException("SetObject can only be used for Permutation or Object keys");

            var accessor = GetObjectParameterHelper(key);
            if (key.Type == ParameterKeyType.Permutation)
            {
                var oldValue = ObjectValues[accessor.Offset];
                if ((oldValue != null && (value == null || !oldValue.Equals(value))) // oldValue non null => check equality
                    || (oldValue == null && value != null)) // oldValue null => check if value too
                        PermutationCounter++;
            }
            ObjectValues[accessor.Offset] = value;
        }

        public object GetObject(ParameterKey key)
        {
            if (key.Type != ParameterKeyType.Permutation && key.Type != ParameterKeyType.Object)
                throw new InvalidOperationException("GetObject can only be used for Permutation or Object keys");

            var accessor = GetObjectParameterHelper(key, false);
            if (accessor.Offset == -1)
                return null;

            return ObjectValues[accessor.Offset];
        }

        public bool Remove(ParameterKey key)
        {
            for (int i = 0; i < parameterKeyInfos.Count; ++i)
            {
                if (parameterKeyInfos[i].Key == key)
                {
                    parameterKeyInfos.SwapRemoveAt(i);
                    LayoutCounter++;
                    return true;
                }

View on GitHub (pinned to 96fad776d2)