將綁定列表轉換爲通用列表<T>

Question

我需要將綁定（UnityEngine.Component）列表轉換爲通用（T）列表，這可能嗎？怎麼樣？

我使用Unity和C＃，但我想知道一般如何做到這一點。

 List<Component> compList = new List<Component>(); 
     foreach(GameObject obj in objects) // objects is List<GameObject> 
     { 
      var retrievedComp = obj.GetComponent(typeof(T)); 
      if(retrievedComp != null) 
       compList.Add(retrievedComp); 
     } 

     List<T> newList = new List<T>(compList as IEnumerable<T>); // ERROR HERE 

     foreach(T n in newList) 
      Debug.Log(n); 

謝謝！

我認爲這是問題，我得到這個運行時錯誤...

ArgumentNullException: Argument cannot be null. 
Parameter name: collection 
System.Collections.Generic.List`1[TestPopulateClass].CheckCollection (IEnumerable`1 collection) 
System.Collections.Generic.List`1[TestPopulateClass]..ctor (IEnumerable`1 collection) 
DoPopulate.AddObjectsToList[TestPopulate] (System.Reflection.FieldInfo target) (at Assets/Editor/ListPopulate/DoPopulate.cs:201) 
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) 
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation. 
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) 
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) 
DoPopulate.OnGUI() (at Assets/Editor/ListPopulate/DoPopulate.cs:150) 
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) 

Answer 1

你試過

List<T> newList = compList.OfType<T>().Select(x=>x).ToList() 

Answer 2

的事實，T和分量是不同的大多數likley套管類型：List<Component> compList和compList as IEnumerable<T>（由於compList是IEnumerable<Component>而不是IEnumerable<T>，因此它將爲空）。

我想你想：

List<T> compList = new List<T>(); // +++ T instead of GameObject 
    foreach(GameObject obj in objects) // objects is List<GameObject> 
    { 
     // ++++ explict cast to T if GetComponent does not return T 
     var retrievedComp = (T)obj.GetComponent(typeof(T)); 
     if(retrievedComp != null) 
      compList.Add(retrievedComp); 
    } 

    List<T> newList = new List<T>(compList as IEnumerable<T>); // ERROR HERE 

    foreach(T n in newList) 
     Debug.Log(n);