ienumerable

问题 I am trying to check whether IEnumerable<> is null or empty but somehow my if check always fails whenever it is empty. private bool Update() { IEnumerable<RecordHolder> recordHolders = GetData(); // below check doesn't work if (recordHolders == null || !recordHolders.Any()) return false; // .. some other code } public IEnumerable<RecordHolder> GetData() { var isSuccess = PullRemote(url); if (!isSuccess.Result) { yield return default; } // .. some other code } Whenever my GetData() method

问题 I wrote this function to retrieve all Administrators Members SIDs: private IList<byte[]> GetAdministratorsMembersSIDs() { IList<byte[]> adminMembers = new List<byte[]>(); SecurityIdentifier id = new SecurityIdentifier(administratorsSid); string name = id.Translate(typeof(NTAccount)).Value.Split('\\')[1]; using (DirectoryEntry adminGroupEntry = new DirectoryEntry(string.Format("WinNT://./{0},group", name))) { foreach (object member in (IEnumerable)adminGroupEntry.Invoke("Members")) { using

问题 I wrote this function to retrieve all Administrators Members SIDs: private IList<byte[]> GetAdministratorsMembersSIDs() { IList<byte[]> adminMembers = new List<byte[]>(); SecurityIdentifier id = new SecurityIdentifier(administratorsSid); string name = id.Translate(typeof(NTAccount)).Value.Split('\\')[1]; using (DirectoryEntry adminGroupEntry = new DirectoryEntry(string.Format("WinNT://./{0},group", name))) { foreach (object member in (IEnumerable)adminGroupEntry.Invoke("Members")) { using

问题 In the .net framework, there's a generic IEnumerable<T> interface which inherits from the not-generic IEnumerable , and they both have a GetEnumerator() method. The only differents between these two GetEnumerator() is the return type. Now I have a similar design, but when I compile the code, the compiler said: MyInterface<T>.GetItem() ' hides inherited member ' MyInterface.GetItem() '. Use the new keyword if hiding was intended. The MyInterface<T>.GetItem() returns a concrete type T, while

问题 In the .net framework, there's a generic IEnumerable<T> interface which inherits from the not-generic IEnumerable , and they both have a GetEnumerator() method. The only differents between these two GetEnumerator() is the return type. Now I have a similar design, but when I compile the code, the compiler said: MyInterface<T>.GetItem() ' hides inherited member ' MyInterface.GetItem() '. Use the new keyword if hiding was intended. The MyInterface<T>.GetItem() returns a concrete type T, while

问题 Is this a bad idea? Private Class GH_DataStructureEnumerator(Of Q As Types.IGH_Goo) Implements IEnumerable(Of Q) Implements IEnumerator(Of Q) .... .... 'Current, MoveNext, Reset etc.' .... .... Public Function GetEnumerator_Generic() As IEnumerator(Of Q) _ Implements IEnumerable(Of Q).GetEnumerator Return Me End Function End Class This class is only visible as an IEnumerable(Of T) readonly property, and it saves me an additional class that wraps IEnumerator(Of T). But somehow it just seems

问题 I have a bunch of IEnumerable Collections which exact number and types is subject of frequent changes (due to automatic code generation). It looks something like this: public class MyCollections { public System.Collections.Generic.IEnumerable<SomeType> SomeTypeCollection; public System.Collections.Generic.IEnumerable<OtherType> OtherTypeCollection; ... At runtime i want to determine each Type and it's count without having to rewrite the code after every code generation. So i am looking for a

问题 I have the following code that compiles in .NET Framework version 4.0 and above: public abstract class MyBase { } public class MyDerived : MyBase { } public abstract class MyBaseCollection<T> : IList<T> where T : MyBase { protected readonly IList<T> deriveds = new List<T>(); public void Test() { // This line works in .NET versions 4.0 and above, but not in versions below. IEnumerable<MyBase> bases = deriveds; } #region IList members with NotImplementedException // ... #endregion } public

问题 I have the following code that compiles in .NET Framework version 4.0 and above: public abstract class MyBase { } public class MyDerived : MyBase { } public abstract class MyBaseCollection<T> : IList<T> where T : MyBase { protected readonly IList<T> deriveds = new List<T>(); public void Test() { // This line works in .NET versions 4.0 and above, but not in versions below. IEnumerable<MyBase> bases = deriveds; } #region IList members with NotImplementedException // ... #endregion } public

来源： https://stackoverflow.com/questions/1814507/are-there-any-non-repeatable-ienumerable-classes