AssetDatabase.Contains

Description

Is object an asset?

Returns true when an object is an asset (corresponds to a file in the Assets folder), and false if it is not (for example object in the Scene, or an object created at runtime).

using UnityEditor;
using UnityEngine;

public class AssetDatabaseExamples : MonoBehaviour
{
    [MenuItem("AssetDatabase/Contains Example")]
    static void ContainsExample()
    {
        //Material is created in memory and the Asset Database does not know about it
        var material = new Material(Shader.Find("Specular"));
        Debug.Log(AssetDatabase.Contains(material)); //Output will be false
        //Material is then saved to disk as an asset and therefore Asset Database knows that it exists
        AssetDatabase.CreateAsset(material, "Assets/Materials/MyMaterial.mat");
        Debug.Log(AssetDatabase.Contains(material)); //Output will be true
    }
}