# Use Pattern Matching to Avoid ‘As’ Followed by A ‘Null’ Check dotnet_diagnostic.IDE0019.severity = warning
private static Query CreateMoreLikeThisQuery(int postId)
{
var docNum = GetLuceneDocumentNumber(postId);
if (docNum == 0)
return null; 
string data = null; var result = data ?? "value";
if (data == null)
{
data = "value";
}
var result = data; protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType == null && requestContext.HttpContext.Request.Url != null)
throw new InvalidOperationException(string.Format("Page not found: {0}",
requestContext.HttpContext.Request.Url.AbsoluteUri.ToString(CultureInfo.InvariantCulture)));
return SmObjectFactory.Container.GetInstance(controllerType) as Controller;
} 
if (context.RequestContext.HttpContext.Request.UrlReferrer.AbsolutePath ==
context.RequestContext.HttpContext.Request.Url.AbsolutePath)
throw new InvalidOperationException(); 
if (instance == null)
{
lock (Lock)
{
if (instance == null)
instance = new Singleton();
}
} 
AlternateView plainView = AlternateView.CreateAlternateViewFromString(
Regex.Replace(EmailBody, @"<(.|\n)*?>", string.Empty), null, "text/plain");
AlternateView htmlView = AlternateView.CreateAlternateViewFromString(EmailBody, null, "text/html");
MyMsg.AlternateViews.Add(plainView);
MyMsg.AlternateViews.Add(htmlView); using System.Net.Mail; using System.Text.RegularExpressions;