C#

public interface ICalculator
{
    event EventHandler CalculationPerformed;
    event EventHandler<int> CalculatedResult;

    int Add(int Number1, int Number2);
}

public class ManagedClass : ICalculator
{
    public event EventHandler CalculationPerformed;
    public event EventHandler<int> CalculatedResult;

    public int Add(int number1, int number2)
    {
        int result = number1 + number2;
        OnCalculationPerformed(EventArgs.Empty);
        OnCalculatedResult(new EventArgs<int>(result));
        return result;
    }
    protected virtual void OnCalculationPerformed(EventArgs e)
    {
        EventHandler eh = CalculationPerformed;
        if (eh != null)
            eh(this, e);
    }
    protected virtual void OnCalculatedResult(EventArgs<int> e)
    {
        EventHandler<int> eh = CalculatedResult;
        if (eh != null)
            eh(this, e);
    }
}

public delegate void EventHandler<T>(object sender, EventArgs<T> e);
public class EventArgs<T> : EventArgs
{
    private T value;

    public EventArgs(T value)
    {
        this.value = value;
    }

    public T Value
    {
        get { return value; }
    }
}

public static RectangleF Parse(this RectangleF rect, string s)
{
//do something with s
}

public static RectangleF Parse(string s)
{
    RectangleF result = new RectangleF();
    //apply parsed values
    return result;
}

RectangleF rect = RectangleF.Parse("0,0,100,50");

public static class MoreTryParse {
	public static bool TryParse(this RectangleF dummy, string s, out RectangleF rect) {
		float x=0;
		float y=0;
		float w=0;
		float h=0;
		if (s.StartsWith("(") && s.EndsWith(")")) s=s.Substring(1, s.Length-2);
		string[] sa=s.Split(',');
		if (sa.Length==4 && float.TryParse(sa[0], out x) && float.TryParse(sa[1], out y) &&
			float.TryParse(sa[2], out w)&& float.TryParse(sa[3], out h)) {
			rect=new RectangleF(x, y, w, h);
			return true;
		} else {
			rect=new RectangleF(0, 0, 0, 0);
			return false;
		}
	}
}

public void test(string s) {
	RectangleF rect=new RectangleF();
	bool result=rect.TryParse(s, out r1);
	log(s+"  result="+result+"  rect="+rect.ToString());
}

string s = "0.0,0.0,1.0,1.0";
RectangleF rect = RectangleF.Parse(s);

Chesnokov Yuriy wrote:

add public static methods

public static class MoreTryParse {
	public static bool TryParse(static, string s, out RectangleF rect) {
		...
	}
}

public void test(string s) {
	RectangleF rect;
	bool result=RectangleF.TryParse(s, out r1);
	log(s+"  result="+result+"  rect="+rect.ToString());
}

public static bool TryParse(static RectangleF, string s, out RectangleF rect) { ... }

public static bool TryParse(static<T>, string s, out RectangleF rect) where T:RectangleF { ... }

BobJanova wrote:

you never know where they are actually defined.

static class Parser {
    static RectangeF ToRectangeF(string s) {
        ....
    }
}