roslyn Analyze source code with Roslyn Introspective analysis of an analyzer in C#

Example

1. Create a new Console Application
2. Add the NuGet package Microsoft.CodeAnalysis
3. Import the namespaces Microsoft.CodeAnalysis.MSBuild, System.Linq and Microsoft.CodeAnalysis.CSharp.Syntax
4. Write the following example code in the Main method:

// Declaring a variable with the current project file path.
const string projectPath = @"C:\<your path to the project\<project file name>.csproj";

// Creating a build workspace.
var workspace = MSBuildWorkspace.Create();
        
// Opening this project.
var project = workspace.OpenProjectAsync(projectPath).Result;

// Getting the compilation.
var compilation = project.GetCompilationAsync().Result;

// As this is a simple single file program, the first syntax tree will be the current file.
var syntaxTree = compilation.SyntaxTrees.First();

// Getting the root node of the file.
var rootSyntaxNode = syntaxTree.GetRootAsync().Result;

// Finding all the local variable declarations in this file and picking the first one.
var firstLocalVariablesDeclaration = rootSyntaxNode.DescendantNodesAndSelf().OfType<LocalDeclarationStatementSyntax>().First();

// Getting the first declared variable in the declaration syntax.
var firstVariable = firstLocalVariablesDeclaration.Declaration.Variables.First();

// Getting the text of the initialized value.
var variableInitializer = firstVariable.Initializer.Value.GetFirstToken().ValueText;

// This will print to screen the value assigned to the projectPath variable.
Console.WriteLine(variableInitializer);

Console.ReadKey();

When running the project, you will see the variable declared on top printed to the screen. This means that you successfully self analysed a project and found a variable in it.