kevin Mocha

But what if I want to do some validation WITHIN the button's Click event handler and if the validation fails, I DON'T WANT to close the dialog?

First solution: Set OKCmd.DialogResult = DialogResult.None (string "None" in the designer) and close the form manually:

Second solution: Leave the OKCmd.DialogResult = DialogResult.OK, but prevent the form to automatically close when the user enters invalid logon information. Here is how:

Advantages to Using Private Static Methods

Kevin Mocha — Mon, 14 Jun 2010 20:12:46 GMT

http://stackoverflow.com/questions/135020/advantages-to-using-private-static-methods

After you mark the methods as static, the compiler will emit non-virtual call sites to these members. Emitting non-virtual call sites will prevent a check at runtime for each call that ensures that the current object pointer is non-null. This can result in a measurable performance gain for performance-sensitive code. In some cases, the failure to access the current object instance represents a correctness issue.

Static methods are useful, because just by looking at its signature, you know that the calling it doesn't use or modify the current instance's state.

Dynamically Composing Expression Predicates

Kevin Mocha — Fri, 04 Jun 2010 21:38:48 GMT

http://www.albahari.com/nutshell/predicatebuilder.aspx

http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx

Visitor class

    /// <summary> ///
A visitor that filters visited items /// </summary> ///
<typeparam name="T">The type of item to be visited</typeparam> public class FilterVisitor<T>
: IVisitor<T> { #region Private Members ///
<summary> /// The function to use for filtering items ///
</summary> private readonly Func<T, bool>
_filterFunction; /// <summary> ///
The filtered items /// </summary> private readonly List<T>
_result; #endregion #region Constructor ///
<summary> /// Constructor ///
</summary> /// <param name="filterFunction">The
function to use for filtering items</param> public FilterVisitor(Func<T, bool>
filterFunction) { _filterFunction = filterFunction; _result = new List<T>();
} /// <summary> /// Constructor ///
</summary> /// <param name="expression">The lambda
expression to use for filtering items</param> public FilterVisitor(Expression<Func<T, bool>>
expression) { _filterFunction = expression.Compile(); _result
= new List<T>(); } #endregion #region Public
Properties /// <summary> /// The
filtered items /// </summary> public List<T>
Result { get { return _result; } } #endregion #region IVisitor<T>
Members /// <summary> /// Visits
the specified item, and adds the item to the result if the filter function is true ///
</summary> /// <param name="item">The item to
be evaluated</param> public void Visit(T
item) { if (_filterFunction(item)) { _result.Add(item);
} } #endregion } }