ParameterAttributes Enumeration
Defines the attributes that can be associated with a parameter. These are defined in CorHdr.h.
This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.
Namespace: System.Reflection
Assembly: mscorlib (in mscorlib.dll)
| Member name | Description | |
|---|---|---|
![]() ![]() | None | Specifies that there is no parameter attribute. |
![]() ![]() | In | Specifies that the parameter is an input parameter. |
![]() ![]() | Out | Specifies that the parameter is an output parameter. |
![]() ![]() | Retval | Specifies that the parameter is a return value. |
![]() ![]() | Optional | Specifies that the parameter is optional. |
![]() ![]() | ReservedMask | Specifies that the parameter is reserved. |
![]() ![]() | HasDefault | Specifies that the parameter has a default value. |
![]() ![]() | HasFieldMarshal | Specifies that the parameter has field marshaling information. |
![]() ![]() | Reserved3 | Reserved. |
![]() ![]() | Reserved4 | Reserved. |
![]() ![]() | Lcid | Specifies that the parameter is a locale identifier. Not supported. Present in Silverlight for Windows Phone. |
To get the ParameterAttributes value, first get the Type. From the Type, get the ParameterInfo array. The ParameterAttributes value is within the array.
These enumerator values are dependent on optional metadata. Not all attributes are available from all compilers. See the appropriate compiler instructions to determine which enumerated values are available.
The following example displays the attributes of four parameters.
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To run this example, see Building Examples That Use a Demo Method and a TextBlock Control. |
Imports System.Reflection Imports System.Runtime.InteropServices Class Example Public Shared Sub mymethod(ByVal str1 As String, ByRef str2 As String, _ <Out> ByRef str3 As String, <InAttribute> ByVal str4 As String) ' Add str1 to str2, which is ByRef. str2 &= str1 ' When mymethod is called, str3 has no value. Give it one. str3 = "new value" End Sub Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock) ' Get the method. Dim mm As MethodInfo = GetType(Example).GetMethod("mymethod") ' Display the method. outputBlock.Text &= "MethodInfo.ToString(): " & mm.ToString() & vbCrLf For Each param In mm.GetParameters() outputBlock.Text &= String.Format("Attributes for parameter {0}, ""{1}"": {2} ({3})", _ param.Position, param.Name, param.Attributes, CInt(param.Attributes)) If param.ParameterType.IsByRef Then outputBlock.Text &= "; the parameter type is ByRef" & vbLf Else outputBlock.Text &= vbLf End If Next End Sub End Class ' This code produces the following output: ' 'MethodInfo.ToString(): Void mymethod(System.String, System.String ByRef, System.String ByRef) 'Attributes for parameter 0, "str1": None (0) 'Attributes for parameter 1, "str2": None (0); the parameter type is ByRef 'Attributes for parameter 2, "str3": Out (2); the parameter type is ByRef 'Attributes for parameter 3, "str4": In (1)
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.


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