The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘C# 2.0’ Category

Great diagram on composing a LINQ query – via Mastering C# – CodeProject

Posted by jpluimers on 2017/08/17

One of the best to graphs diagrams of LINQ I know is in Mastering C# – Lecture Notes Part 2 of 4 – CodeProject [WayBack]

The LINQ explanation in that article [WayBack] is top notch as well. Thanks Florian Rappl [WayBack]!

–jeroen

Posted in .NET, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, C# 6 (Roslyn), Development, Software Development | Leave a Comment »

.NET/C# some links on querying the ActiveDirectory

Posted by jpluimers on 2016/12/15

Without dsquery installable, I had to query an ActiveDirectory spanning two domains.

Here are some links that helped:

–jeroen

Posted in .NET, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, C# 6 (Roslyn), Development, Software Development | Leave a Comment »

Yes Dorothy, the .NET System.Array Class can throw you a NotSupportedException

Posted by jpluimers on 2016/09/21

It’s been in the System.Array class forever, but remarkably few people do know that it can throw you a NotSupportedException (for instance when calling Add, Insert, Remove, etc).

It does because it implements IList, but not all methods implemented from IList are valid.

And it also indicates that, as the IList Properties allows for IsFixedSize to return false.

A similar case is there for IsReadOnly: then you cannot even modify the values.

Ever since I started teaching .NET/C# classes almost 15 years ago, I warned:

beware when you use IList as not everybody implements all methods.

–jeroen

via:

Posted in .NET, .NET 1.x, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, C# 6 (Roslyn), Development, Software Development | Leave a Comment »

.NET/C#: two ways of creating an empty array

Posted by jpluimers on 2016/08/18

Empty arrays are not used often as arrays usually are about the presence data, not about the absence.

Here are two ways based on the int data type in C# (the original [WayBackexamples [WayBack] are using string, but since string itself is also a kind of array…):

Specify a size of zero:

int[] a = new int[0];

Specify an empty initialisation:

int[] a = new int[] { };

Though many people think arrays are a thing of the past, I think it is one of the first generic types and have their place. For one, enumerating over arrays using foreach is a lot faster in many environments than enumerating over other data types. Another thing is that the fixed nature of arrays can be very beneficial in setting constraints.

That’s why I like the balanced view from Eric Lippert [WayBack] in Arrays considered somewhat harmful – Fabulous Adventures In Coding – Site Home – MSDN Blogs [WayBack]

–jeroen

via:

Posted in .NET, .NET 1.x, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, C# 6 (Roslyn), Development, Software Development | Leave a Comment »

C#, XSD.exe, xsd2code and generating nullable fields+properties from an XSD with and without Specified fields/properties

Posted by jpluimers on 2016/07/27

It comes down to these cases for XML elements having maxOccurs="1" (which the default for maxOccurs):

  1. adding nillable="true" will convert from a regular type to a nullable type.
  2. adding minOccurs="0" will add boolean …Specified properties in the generated C# for each element.
  3. you can have both nillable="true" and minOccurs="0" in an element which gets you a nullable type and a …Specified property.

Note I’m not considering fixed or default here, nor attributes (that have use instead of minOccurs/maxOccurs, but do not allow for nillable) nor larger values of maxOccurs (which both xsd.exe and xsd2code regard as unbounded).

From the above, XML has a richer type system than C#, so in XML there are subtle a differences between:

  1. an explicit nil in the XML element
  2. the XML element being absent
  3. the XML element being empty.

Hopefully later more text and examples to show how to actually work with this.

Delphi related to minOccurs:

Note that xsd2code.codeplex.com (unlike XmlGen#) has at least two forks at github:

From the specs:

–jeroen

Posted in .NET, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, C# 6 (Roslyn), Conference Topics, Conferences, Development, Event, Software Development, XML, XML/XSD, XSD | Leave a Comment »

 
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