创建对象时自动生成属性

Question

我的类有很多属性，我想知道当我创建对象时，Visual Studio、Resharper 或其他工具有什么方法可以创建调用属性的语法。所以我不必自己检查所有属性，只需设置值即可。像这样的东西。

Object foo = new Object{
    prop1 = ,
    prop2 = ,
    prop3 = };

我不知道人们是否理解这个问题。我希望 Visual Studio 在创建对象时为属性创建设置器。不是财产本身。

Answer 1

您可以在构造函数中使用命名参数：

http://geekswithblogs.net/michelotti/archive/2009/01/22/c-4.0-named-parameters-for-better-code-quality.aspx

例如：

Person person = new Person(firstName: "John", lastName: "Smith", dateOfBirth: new DateTime(1970, 1, 1));

Answer 2

编辑 误解了问题

我有一个来自这一行的宏

MyClass x = new MyClass();

生成

x.StrProp = "string";
x.IntProp = 0;

我使用它来生成测试代码，但您可以更改 PrintMemberAssignment 函数以显示您喜欢的结果：

宏如下所示（将其分配给键盘快捷键）

Private mUsings As New HashSet(Of String)

Sub InitializeAllMembers()
    Try
        Dim assignmentPattern As New Regex("(?<Indent>\s*)(?:(?<DeclaredType>\S+)\s+)?(?<VariableName>[\S=]+)\s*=\s*(?<new>new)?\s*(?<CreatedType>[^\s\(]+)")
        Dim selection As EnvDTE.TextSelection = CType(DTE.ActiveDocument.Selection(), EnvDTE.TextSelection)
        Dim editPoint As EditPoint = selection.BottomPoint.CreateEditPoint

        ' Get info from current line in editor
        editPoint.StartOfLine()
        Dim match As Match = assignmentPattern.Match(editPoint.GetText(editPoint.LineLength))
        If Not match.Success Then
            MessageBox.Show("No assignment on row")
            Exit Sub
        End If
        Dim foundDeclaredType As Boolean = match.Groups("DeclaredType").Success AndAlso match.Groups("DeclaredType").Value <> "var"
        Dim foundCreatedType As Boolean = match.Groups("new").Success

        If Not (foundDeclaredType OrElse foundCreatedType) Then
            MessageBox.Show("Can't find type on row")
            Exit Sub
        End If

        Dim typeToExpand As String = If(foundDeclaredType, match.Groups("DeclaredType"), match.Groups("CreatedType")).Value

        ' Traverse upwards in current file and record all using statements
        Dim currentFunction As CodeElement = FindCodeElement(selection.ActivePoint, DTE.ActiveDocument.ProjectItem.FileCodeModel.CodeElements)
        If currentFunction Is Nothing Then
            MessageBox.Show("Can't find current function")
            Exit Sub
        End If
        mUsings.Clear()
        FindAllUsings(currentFunction)

        ' Loop all projects in solution to find requested type
        Dim classType As CodeElement = DTE.Solution.Projects.Cast(Of Project) _
                                                            .Select(Function(x) FindClassInProjectItems(x.ProjectItems, typeToExpand)) _
                                                            .FirstOrDefault(Function(x) x IsNot Nothing)
        If classType Is Nothing Then
            MessageBox.Show("Can't find type in solution: " & typeToExpand)
            Exit Sub
        End If

        PrintMemberAssignments(editPoint, match.Groups("Indent").Value & match.Groups("VariableName").Value, GetMembers(classType))

    Catch objException As System.Exception
        MessageBox.Show(objException.Message)
    End Try
End Sub

' Records all using statements active for a codeelement
Sub FindAllUsings(ByVal elem As Object)
    If TypeOf elem Is CodeFunction Then
        FindAllUsings(CType(elem, CodeFunction).Parent)
    ElseIf TypeOf elem Is CodeClass Then
        mUsings.Add(CType(elem, CodeClass).FullName)
        FindAllUsings(CType(elem, CodeClass).Parent)
    ElseIf TypeOf elem Is CodeStruct Then
        mUsings.Add(CType(elem, CodeStruct).FullName)
        FindAllUsings(CType(elem, CodeStruct).Parent)
    ElseIf TypeOf elem Is CodeNamespace Then
        mUsings.Add(CType(elem, CodeNamespace).FullName)
        For Each ns As String In CType(elem, CodeNamespace).Members.OfType(Of CodeImport) _
                                                                   .Select(Function(x) x.Namespace)
            mUsings.Add(ns)
        Next
        FindAllUsings(CType(elem, CodeNamespace).Parent)
    ElseIf TypeOf elem Is FileCodeModel Then
        For Each ns As String In CType(elem, FileCodeModel).CodeElements.OfType(Of CodeImport) _
                                                                        .Select(Function(x) x.Namespace)
            mUsings.Add(ns)
        Next
    End If
End Sub

' Find code element (i.e. function) for current line
Public Function FindCodeElement(ByVal caretPosition As TextPoint, ByVal elems As CodeElements) As CodeElement
    If elems Is Nothing Then Return Nothing
    Return elems.Cast(Of CodeElement) _
                .Where(Function(x) x.StartPoint.LessThan(caretPosition) AndAlso _
                                   x.EndPoint.GreaterThan(caretPosition)) _
                .Select(Function(x) If(FindCodeElement(caretPosition, GetMembers(x)), x)) _
                .FirstOrDefault()
End Function


Public Sub PrintMemberAssignments(ByVal editPoint As EditPoint, ByVal prefix As String, ByVal members As CodeElements)
    For Each member As CodeElement In members
        Dim text As String
        If TypeOf member Is CodeProperty Then
            If CType(member, CodeProperty).Setter Is Nothing Then Continue For
            If CType(member, CodeProperty).Setter.Access <> vsCMAccess.vsCMAccessPublic Then Continue For
            If CType(member, CodeProperty).Setter.IsShared Then Continue For
            text = MemberAssignment(prefix, member.Name, CType(member, CodeProperty).Type)
        ElseIf TypeOf member Is CodeVariable Then
            If CType(member, CodeVariable).Access <> vsCMAccess.vsCMAccessPublic Then Continue For
            If CType(member, CodeVariable).IsConstant Then Continue For
            If CType(member, CodeVariable).IsShared Then Continue For
            text = MemberAssignment(prefix, member.Name, CType(member, CodeVariable).Type)
        Else
            Continue For
        End If
        editPoint.EndOfLine()
        editPoint.Insert(ControlChars.NewLine)
        editPoint.Insert(text)
    Next
End Sub

Private Function MemberAssignment(ByVal prefix As String, ByVal membername As String, ByVal typeref As EnvDTE.CodeTypeRef) As String
    Dim typekind As EnvDTE.vsCMTypeRef = typeref.TypeKind
    Dim value As String
    If typekind = vsCMTypeRef.vsCMTypeRefArray Then
        value = "{0}.{1} = new {2}[1];"
        If typeref.ElementType.TypeKind = vsCMTypeRef.vsCMTypeRefCodeType Then
            value = value & ControlChars.NewLine & "{0}.{1}[0] = new {2}();"
        End If
        Return String.Format(value, prefix, membername, TrimKnownNamespace(typeref.ElementType.AsString))
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefBool Then
        value = "false"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefChar Then
        value = "'x'"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefDecimal Then
        value = "0.00m"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefDouble Then
        value = "0.00"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefInt Then
        value = "0"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefLong Then
        value = "0"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefShort Then
        value = "0"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefByte Then
        value = "0"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefString Then
        value = """" & membername & """"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefArray Then
        value = "new " & TrimKnownNamespace(typeref.ElementType.AsString) & "[1]"
    ElseIf typekind = vsCMTypeRef.vsCMTypeRefCodeType AndAlso _
            typeref.AsString = "System.DateTime" Then
        value = String.Format("new DateTime({0:yyyy},{0:%M},{0:%d})", DateTime.Today)
    Else
        value = "new " & TrimKnownNamespace(typeref.AsString) & "()"
    End If
    Return String.Format("{0}.{1} = {2};", prefix, membername, value)
End Function

Private Function TrimKnownNamespace(ByVal fullName As String) As String
    Return fullName.Substring(mUsings.Where(Function(x) fullName.StartsWith(x) AndAlso _
                                                        fullName.Length > x.Length AndAlso _
                                                        fullName(x.Length) = "."c) _
                                     .Select(Function(x) x.Length + 1) _
                                     .DefaultIfEmpty(0) _
                                     .Max())
End Function

Private Function FindClassInProjectItems(ByVal nprojectItems As ProjectItems, ByVal classname As String) As CodeElement
    If nprojectItems Is Nothing Then Return Nothing
    For Each nprojectitem As ProjectItem In nprojectItems
        Dim found As CodeElement
        If nprojectitem.Kind = EnvDTE.Constants.vsProjectItemKindPhysicalFile Then
            If nprojectitem.FileCodeModel Is Nothing Then Continue For
            found = FindClassInCodeElements(nprojectitem.FileCodeModel.CodeElements, classname)
            If found IsNot Nothing Then Return found
        End If
        If nprojectitem.SubProject IsNot Nothing Then
            found = FindClassInProjectItems(nprojectitem.SubProject.ProjectItems, classname)
            If found IsNot Nothing Then Return found
        End If
        found = FindClassInProjectItems(nprojectitem.ProjectItems, classname)
        If found IsNot Nothing Then Return found
    Next
End Function

Private Function FindClassInCodeElements(ByVal elems As CodeElements, ByVal classname As String) As CodeElement
    If elems Is Nothing Then Return Nothing
    For Each elem As CodeElement In elems
        If IsClassType(elem) Then
            If classname = elem.Name Then Return elem
        ElseIf Not TypeOf elem Is CodeNamespace Then
            Continue For
        End If
        If mUsings.Contains(elem.FullName) Then
            Dim found As CodeElement = FindClassInCodeElements(GetMembers(elem), classname)
            If found IsNot Nothing Then Return found
        End If
    Next
    Return Nothing
End Function

Private Function GetMembers(ByVal elem As CodeElement) As CodeElements
    If TypeOf elem Is CodeClass Then
        Return CType(elem, CodeClass).Members
    ElseIf TypeOf elem Is CodeNamespace Then
        Return CType(elem, CodeNamespace).Members
    ElseIf TypeOf elem Is CodeStruct Then
        Return CType(elem, CodeStruct).Members
    ElseIf TypeOf elem Is CodeInterface Then
        Return CType(elem, CodeInterface).Members
    End If
    Return Nothing
End Function

Private Function IsClassType(ByVal elem As CodeElement) As Boolean
    Return TypeOf elem Is CodeClass OrElse TypeOf elem Is CodeStruct OrElse TypeOf elem Is CodeInterface
End Function

Answer 3

您可以使用匿名对象：

var foo = new { one = 1, two = 2, three = 3};

在这种情况下，将创建具有属性one、two 和three 的新对象

Answer 4

Intellisense 不是为您做最多的工作吗？通常，只要您打开 { an press space，它就会向您显示所有属性的列表。