GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();

public class MyClass
{
    private int _wiFiChangesCounter = 0;
    public MyClass(WiFiManager wiFiManager)
    {
        wiFiManager.WiFiSignalChanged += (s, e) => _wiFiChangesCounter++;
    }

public class MyClass
{
    public MyClass(WiFiManager wiFiManager)
    {
        Timer timer = new Timer(HandleTick);
        timer.Change(TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(5));
    }
    private void HandleTick(object state)
    {
        // do something
    }

public void Foo()
{
    using (var stream = new FileStream(@"C:\Temp\SomeFile.txt",
                                       FileMode.OpenOrCreate))
    {
        // do stuff
    }// stream.Dispose() will be called even if an exception occurs

public class MyClass : IDisposable
{
    private IntPtr _bufferPtr;
    public int BUFFER_SIZE = 1024 * 1024; // 1 MB
    private bool _disposed = false;
    public MyClass()
    {
        _bufferPtr =  Marshal.AllocHGlobal(BUFFER_SIZE);
    }
    protected virtual void Dispose(bool disposing)
    {
        if (_disposed)
            return;
        if (disposing)
        {
            // Free any other managed objects here.
        }
        // Free any unmanaged objects here.
        Marshal.FreeHGlobal(_bufferPtr);
        _disposed = true;
    }
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }
    ~MyClass()
    {
        Dispose(false);
    }
}

Process currentProc = Process.GetCurrentProcess();
var bytesInUse = currentProc.PrivateMemorySize64;

PerformanceCounter ctr1 = new PerformanceCounter("Process", "Private Bytes", Process.GetCurrentProcess().ProcessName);
PerformanceCounter ctr2 = new PerformanceCounter(".NET CLR Memory", "# Gen 0 Collections", Process.GetCurrentProcess().ProcessName);
PerformanceCounter ctr3 = new PerformanceCounter(".NET CLR Memory", "# Gen 1 Collections", Process.GetCurrentProcess().ProcessName);
PerformanceCounter ctr4 = new PerformanceCounter(".NET CLR Memory", "# Gen 2 Collections", Process.GetCurrentProcess().ProcessName);
PerformanceCounter ctr5 = new PerformanceCounter(".NET CLR Memory", "Gen 0 heap size", Process.GetCurrentProcess().ProcessName);
//...
Debug.WriteLine("ctr1 = " + ctr1 .NextValue());
Debug.WriteLine("ctr2 = " + ctr2 .NextValue());
Debug.WriteLine("ctr3 = " + ctr3 .NextValue());
Debug.WriteLine("ctr4 = " + ctr4 .NextValue());
Debug.WriteLine("ctr5 = " + ctr5 .NextValue());

[Test]
void MemoryLeakTest()
{
  var weakRef = new WeakReference(leakyObject)
  // Ryn an operation with leakyObject
  GC.Collect();
  GC.WaitForPendingFinalizers();
  GC.Collect();
  Assert.IsFalse(weakRef.IsAlive);
}

MemAssertion.NoInstances(typeof(MyLeakyClass));
MemAssertion.NoNewInstances(typeof(MyLeakyClass), lastSnapshot);
MemAssertion.MaxNewInstances(typeof(Bitmap), 10);