ソースコード

using UnityEngine;

public static class GameObjectExtensions
{
    /// <summary>
    /// インターフェイスを指定してコンポーネントを取得します
    /// </summary>
    public static T GetInterfaceOfComponent<T>( this GameObject self ) where T : class
    {
        foreach ( var n in self.GetComponents<Component>() )
        {
            var component = n as T;
            if ( component != null )
            {
                return component;
            }
        }
        return null;
    }
}

使い方

interface ICharacter
{
}

public class Character : MonoBehaviour, ICharacter
{
}

var character = gameObject.GetInterfaceOfComponent<ICharacter>();

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