使用 Roslyn 向类添加新的字段声明

Question

有没有办法使用 roslyn 将成员添加到类中？我想补充：

public int number {get;set;}

更新 我使用了以下代码：

PropertyDeclarationSyntax o =  
SyntaxFactory.PropertyDeclaration(SyntaxFactory.ParseTypeName("public  
System.Windows.Forms.Timer"), "Ticker { get; set; }");
var newRoot = root.ReplaceNode(oldMethod, oldMethod.AddMembers(o));
newRoot = Formatter.Format(newRoot, new AdhocWorkspace());
File.WriteAllText(file, newRoot.ToFullString());

但结果是这样的：

public class ClassChild
{
public int n;
private int n2;
public void method1()
{
string c = "";
Console.WriteLine();
}
public System.Windows.Forms.TimerTicker { get; set; }
}

}

我想用n和n2内联公共System.Windows.Forms.TimerTicker{get; set; }。我该怎么做？

Answer 1

查看代码

private PropertyDeclarationSyntax MakeProperty()
{
string name = "n";
// Create an auto-property
var property =
SyntaxFactory.PropertyDeclaration(SyntaxFactory.ParseTypeName("int"), name)
.AddModifiers(SyntaxFactory.Token(SyntaxKind.PublicKeyword))
.AddAccessorListAccessors(
SyntaxFactory.AccessorDeclaration(SyntaxKind.GetAccessorDeclaration).WithSemicolonToken(SyntaxFactory.Token(SyntaxKind.SemicolonToken)),
SyntaxFactory.AccessorDeclaration(SyntaxKind.SetAccessorDeclaration).WithSemicolonToken(SyntaxFactory.Token(SyntaxKind.SemicolonToken))
);
return property;
}
private async Task<Document> AddProperty(Document document, ClassDeclarationSyntax classeDecl, CancellationToken cancellationToken)
{
var root = await document.GetSyntaxRootAsync(cancellationToken);
var newClass = classeDecl.AddMembers(MakeProperty());
return document.WithSyntaxRoot(root.ReplaceNode(classeDecl, newClass));
}

自动属性生成示例取自此问题。

Answer 2

就个人而言，我更喜欢这种技术：

public static class SyntaxHelpers
{
public static T GenerateClassNode<T>(string decl) where T : CSharpSyntaxNode
{
var declaration = SyntaxFactory.ParseCompilationUnit(
" public class FSM { rn" +
$"{decl}rn" +
" }} rn");
var field = declaration.Members[0].DescendantNodes().First() as T;
return field;
}
}

然后，您可以按如下方式使用它：

string log4NetLoggerDeclaration =
"private static readonly log4net.ILog Logger = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);";
var log4NetDeclarationStatement = SyntaxHelpers.GenerateClassNode<FieldDeclarationSyntax>(log4NetLoggerDeclaration);
string declarationString = log4NetLoggerDeclaration.ToString();