How do I generate a constructor from class fields using Visual Studio (and/or ReSharper)?

Question

I\'ve gotten accustomed to many of the Java IDEs (Eclipse, NetBeans, and IntelliJ IDEA) providing you with a command to generate a default constructor for a class based on t

Answer 1

Here's JMarsh's Visual Studio macro modified to generate a constructor based on the fields and properties in the class.

Imports System
Imports EnvDTE
Imports EnvDTE80
Imports EnvDTE90
Imports EnvDTE100
Imports System.Diagnostics
Imports System.Collections.Generic

Public Module ConstructorEditor

    Public Sub AddConstructorFromFields()

        Dim classInfo As CodeClass2 = GetClassElement()
        If classInfo Is Nothing Then
            System.Windows.Forms.MessageBox.Show("No class was found surrounding the cursor.  Make sure that this file compiles and try again.", "Error")
            Return
        End If

        ' Setting up undo context. One Ctrl+Z undoes everything
        Dim closeUndoContext As Boolean = False
        If DTE.UndoContext.IsOpen = False Then
            closeUndoContext = True
            DTE.UndoContext.Open("AddConstructorFromFields", False)
        End If

        Try
            Dim dataMembers As List(Of DataMember) = GetDataMembers(classInfo)
            AddConstructor(classInfo, dataMembers)
        Finally
            If closeUndoContext Then
                DTE.UndoContext.Close()
            End If
        End Try

    End Sub

    Private Function GetClassElement() As CodeClass2
        ' Returns a CodeClass2 element representing the class that the cursor is within, or null if there is no class
        Try
            Dim selection As TextSelection = DTE.ActiveDocument.Selection
            Dim fileCodeModel As FileCodeModel2 = DTE.ActiveDocument.ProjectItem.FileCodeModel
            Dim element As CodeElement2 = fileCodeModel.CodeElementFromPoint(selection.TopPoint, vsCMElement.vsCMElementClass)
            Return element
        Catch
            Return Nothing
        End Try
    End Function

    Private Function GetDataMembers(ByVal classInfo As CodeClass2) As System.Collections.Generic.List(Of DataMember)

        Dim dataMembers As List(Of DataMember) = New List(Of DataMember)
        Dim prop As CodeProperty2
        Dim v As CodeVariable2

        For Each member As CodeElement2 In classInfo.Members

            prop = TryCast(member, CodeProperty2)
            If Not prop Is Nothing Then
                dataMembers.Add(DataMember.FromProperty(prop.Name, prop.Type))
            End If

            v = TryCast(member, CodeVariable2)
            If Not v Is Nothing Then
                If v.Name.StartsWith("_") And Not v.IsConstant Then
                    dataMembers.Add(DataMember.FromPrivateVariable(v.Name, v.Type))
                End If
            End If

        Next

        Return dataMembers

    End Function

    Private Sub AddConstructor(ByVal classInfo As CodeClass2, ByVal dataMembers As List(Of DataMember))

        ' Put constructor after the data members
        Dim position As Object = dataMembers.Count

        ' Add new constructor
        Dim ctor As CodeFunction2 = classInfo.AddFunction(classInfo.Name, vsCMFunction.vsCMFunctionConstructor, vsCMTypeRef.vsCMTypeRefVoid, position, vsCMAccess.vsCMAccessPublic)

        For Each dataMember As DataMember In dataMembers
            ctor.AddParameter(dataMember.NameLocal, dataMember.Type, -1)
        Next

        ' Assignments
        Dim startPoint As TextPoint = ctor.GetStartPoint(vsCMPart.vsCMPartBody)
        Dim point As EditPoint = startPoint.CreateEditPoint()
        For Each dataMember As DataMember In dataMembers
            point.Insert("            " + dataMember.Name + " = " + dataMember.NameLocal + ";" + Environment.NewLine)
        Next

    End Sub

    Class DataMember

        Public Name As String
        Public NameLocal As String
        Public Type As Object

        Private Sub New(ByVal name As String, ByVal nameLocal As String, ByVal type As Object)
            Me.Name = name
            Me.NameLocal = nameLocal
            Me.Type = type
        End Sub

        Shared Function FromProperty(ByVal name As String, ByVal type As Object)

            Dim nameLocal As String
            If Len(name) > 1 Then
                nameLocal = name.Substring(0, 1).ToLower + name.Substring(1)
            Else
                nameLocal = name.ToLower()
            End If

            Return New DataMember(name, nameLocal, type)

        End Function

        Shared Function FromPrivateVariable(ByVal name As String, ByVal type As Object)

            If Not name.StartsWith("_") Then
                Throw New ArgumentException("Expected private variable name to start with underscore.")
            End If

            Dim nameLocal As String = name.Substring(1)

            Return New DataMember(name, nameLocal, type)

        End Function

    End Class

End Module