[Extension Method][VB.NET]使用擴充方法過濾出組件內的特定類別

今天把之前的[C#][VB.NET]取得專案內所有表單名稱這篇程式給修了一下,順便把其概念提出成擴充方法,整理如下:

Imports System.Reflection
Imports System.Runtime.CompilerServices

Module AssembleExtension
<Extension()>
Public Function GetTypes(ByVal asm As Assembly, ByVal filterTypeName As String, Optional ByVal includeSubClass As Boolean = False) As Type()
Return GetTypes(asm, Type.GetType(filterTypeName), includeSubClass)
End Function

<Extension()>

Public Function GetTypes(ByVal asm As Assembly, ByVal filterType As Type, Optional ByVal includeSubClass As Boolean = False) As Type()
Dim linq = From t In asm.GetTypes Where t Is filterType OrElse (includeSubClass AndAlso t.IsSubclassOf(filterType)) Select t
Return linq.ToArray
End Function
End Module




使用上取得Assembly物件後,呼叫GetTypes,並傳入要過濾的型態等參數,即可取得過濾完的類型。

舉個例子來看,假設還是要取得專案中所有表單的話,程式可以簡化成下面這樣:

Dim formTypes() as Type = Assembly.GetExecutingAssembly.GetTypes(GetType(Form), True)