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

2010-04-16

7488
0
VB.NET
2010-04-17

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.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：