来自图书馆的反思 [英] Reflection from Library dll

问题描述

我想使用反射来显示调用程序集中设置的全局值。



在调用程序集中我有一个主模块指定全程使用的许多全局变量。我还希望能够在库dll中使用它们。



程序集的根命名空间是ERP_Generic。主模块的名称是Main。



主要模块:(显然所有这些都是为了说明目的非常简化）

I want to use reflection to reveal the values of global from that are set in the calling assembly.

In the calling assembly I have a main module that specifies many global variables used throughout. I also want to be able to use these in the library dll.

The root namespace of the assembly is "ERP_Generic". The name of the main module is "Main".

The main module: (obviously all this is very simplified for illustration purposes)

Module Main
Public MNApplDir As String = "C:\Program\MyAppDir"
End Module

在库dll中，我有一个测试子：

In the library dll, I have a test sub:

Public Sub Test1()
    Dim mParentAssy As Assembly = Assembly.GetEntryAssembly ' the assembly that called this library class
    Dim moduleType As Type = mParentAssy.GetType("ERP_Generic.Main")
    Dim myFields As FieldInfo() = moduleType.GetFields((BindingFlags.Public Or BindingFlags.Instance))
    Dim mFldName As String = myFields(0).Name
    Dim istr As String = myFields(0).GetValue(mParentAssy)
End Sub

当调用此子程序并逐步执行它时，myFields数组没有任何成员。



我不知道为什么module.GetFields找不到字段。

When this sub is called and I step through it, the myFields array does not have any members.

I don't know why the module.GetFields can't find the fields.

推荐答案

我已经弄明白了。 FieldInfo行已更改为：



Dim myFields As FieldInfo（）= moduleType.GetFields（）



我添加了一个循环来查找我正在寻找的变量：

I have figured it out. The FieldInfo line has been changed to:

Dim myFields As FieldInfo() = moduleType.GetFields()

And I have added a loop to find the variables I am seeking:

For i As Short = 0 To myFields.Length - 1 Step 1
    If myFields(i).Name = "MNApplDir" Then
        MNApplDir = myFields(i).GetValue(mParentAssy)
    End If
Next i

这是正常的。

This works correctly.

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