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 ‘Software Development’ Category

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.NET/C#: When XmlSerializer throws “Unable to generate a temporary class (result=1).” / “error CS2001”

Posted by jpluimers on 2014/02/06

A while ago, I had this error when running an application on a hardened server:

Unhandled Exception:System.InvalidOperationException:
Unable to generate a temporary class (result=1).
error CS2001: Source file 'C:\windows\TEMP\0hocq2nq.0.cs' could not be found  error CS2008: No inputs specified
at System.Xml.Serialization.Compiler.Compile(Assembly parent, String ns, XmlSerializerCompilerParameters xmlParameters, Evidence evidence)
at System.Xml.Serialization.TempAssembly.GenerateAssembly(XmlMapping[] xmlMappings, Type[] types, String defaultNamespace, Evidence evidence, XmlSerializerCompilerParameters parameters, Assembly assembly, Hashtable assemblies)
at System.Xml.Serialization.TempAssembly..ctor(XmlMapping[] xmlMappings, Type[] types, String defaultNamespace, String location, Evidence evidence)
at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace, String location, Evidence evidence)
at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace, String location)
at System.Xml.Serialization.XmlSerializer..ctor(Type type, Type[] extraTypes)

Usually I’m not the first with strange errors, but searching for “Unhandled Exception:System.InvalidOperationException: Unable to generate a temporary class” didn’t get many results.

This was a program running from SSIS under a non-system domain account with very little access.

My first guess was the right now: the XmlSerializer wants to generate a temporary C# file, then compile it into a temporary assembly. Since it cannot generate the C# file because the account does not have access to %windir\TEMP%, the compiler cannot find the (not generated) C# file.

After a few tries, I searched for XmlSerializer without GenerateAssembly, where the first hit ended at Changing where XmlSerializer Outputs Temporary Assemblies – Scott Hanselman.

That post indicated I should try looking for tempFilesLocation in the XmlSerializer context.

That got me these posts: Read the rest of this entry »

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, Development, Software Development | Leave a Comment »

.NET/C#/VB.NET – Default value for generics (via: Stack Overflow)

Posted by jpluimers on 2014/02/05

Looking for the pesky little differences between C# and VB.NET, I stumbled over this nice question by Micah Martin on default values for generics in VB.NET as compared to C#. Actually there were 3 questions, so I did a bit of post-editing:

How do I create the default for a generic in VB.NET? in C# I can call:
T variable = default(T);

  1. How do I do this in VB?
  2. If this just returns null (C#) or nothing (VB.NET) then what happens to value types?
  3. Is there a way to specify for a custom type what the default value is? For instance what if I want the default value to be the equivalent to calling a parameterless constructor on my class.

User Konrad Rudolph – Stack Overflow. promptly gave three answers:

Question 1:

Dim variable As T ‘ or ‘ Dim variable As T = Nothing ‘ or ‘ Dim variable As New T() Notice that the latter only works if you specifiy either the New or the Structure constraint for the generic type.

Question 2:

For value types all members of the struct are “nulled” out, i.e. all reference type members are set to null (Nothing) and all value types are in turn nulled out. And no, since string is a reference type, it does not result in "" for strings as suggested in the other answer.

Question 3:

No, there’s no way to specify this. There are some threads about this on Stack Overflow already, e.g. here. Jon has posted an excellent explanation why this is.

–jeroen

via: c# – Default value for generics – Stack Overflow.

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, Development, Software Development, VB.NET, VB.NET 10.0, VB.NET 11.0, VB.NET 7.0, VB.NET 7.1, VB.NET 8.0, VB.NET 9.0 | Leave a Comment »

Ready to cast: Chromecast now open to developers with the Google Cast SDK #interesting #fun (via: Chromium Blog)

Posted by jpluimers on 2014/02/03

With a more decent internet connection during our trip, it is time to catch up on some recent news.

The first that caught my eye was that the Chromecast API now is open to all developers.

Developer information is available through Casting Your Content to the Big Screen – Google Cast — Google Developers.

You need to pay a one-time USD 5 fee per development account (how’s that Apple?) for the Google Cast SDK Developer Console.

After that, you will have to register your Chromecast device(s) and custom or styled media receiver apps.

Interesting. Fun.

I hope this can be combined with the new Smart Mobile Studio 2.0 release or the Delphi for Android support.

Will get back on that as soon as I’m back home.

Resources:

More links:

–jeroen

via: Chromium Blog: Ready to cast: Chromecast now open to developers with the Google Cast SDK.

Posted in Chrome, Chromecast, Delphi, Delphi XE5, Development, Google, JavaScript/ECMAScript, Pascal, Power User, Scripting, Smart Mobile Studio, Software Development | 1 Comment »

Hanselman’s Newsletter of Wonderful Things: December 17th, 2013 – Scott Hanselman

Posted by jpluimers on 2014/02/03

Always an interesting read, and usually posted to his blog a while after the email blast gets out.

There is too much information to fully re-post here, so here is an abstract of the entries I already had benefits from, or have a high interest in:

(BTW: don’t you love the that the bug report about WordPress.com adding backslashes in the “Press This” functionality still got no official WordPress response after 3 months?)

–jeroen

via: Hanselman’s Newsletter of Wonderful Things: December 17th, 2013 – Scott Hanselman.

Posted in Development, Power User, Software Development, Windows | Leave a Comment »

idank/explainshell: explainshell.com – match command-line arguments to their help text

Posted by jpluimers on 2014/02/03

This is brilliant for learning *nix shell programming:

explainshell.com – match command-line arguments to their help text

explainshell is a tool (with a web interface) capable of parsing man pages, extracting options and explain a given command-line by matching each argument to the relevant help text in the man page.

It has open source code at gitub too: idank/explainshell.

–jeroen

Posted in *nix, Development, Linux, Power User, Scripting, Sh Shell, Software Development, SuSE Linux | Leave a Comment »

.NET/C#: refactoring some C# 1 code that uses HashTables as a poor mans property bag (via:Stack Overflow)

Posted by jpluimers on 2014/01/30

A while ago, I was refactoring some C# 1 code that uses HashTables as a poor mans property bag.

The problem was that I felt my code was convoluted, and should be denser, especially avoiding Convert.ChangeType. My code was already much simpler than casting tuples to a superclass.

So I asked this question on StackOverflow: c# – Is there a solution that feels less clumsy than Convert.ChangeType to get the value from a HashTable – Stack Overflow.

User dasblinkenlight showed it could be shortened and explained why (hyperlinks are mine):

Since System.String is sealed, the expression

genericType.IsSubclassOf(stringType)

is the same as

genericType == stringType

Therefore you do not need a call of Convert.ChangeType: you can cast to T by casting to object, like this:

object stringResult; // Note the change of type to "object"
if (haveValue)
    stringResult = ((string)properties[propertyName]).Trim();
else
    stringResult = string.Empty;
result = (T)stringResult; // It is allowed to cast object to generic T

The original .NET 1.1 code had loads of null checks wrapped if/then/else statements to assign default values for null values.
I wanted to get rid of that, and get code like this: Read the rest of this entry »

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, Development, Software Development | Leave a Comment »

delphi – With a class operator is an implicit typecast to itself allowed? – Stack Overflow

Posted by jpluimers on 2014/01/29

In the series “interesting stuff you can do with Implicit operators”: delphi – With a class operator is an implicit typecast to itself allowed? – Stack Overflow.

Be careful though, as Implicit assignment will allow more code paths to the compiler than you expect at first sight (:

–jeroen

Posted in Delphi, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development | Leave a Comment »

.NET/C#: fun with enums and aliases part 2

Posted by jpluimers on 2014/01/29

In the .NET/C#: fun with enums and aliases part 1 you saw that an enumerated type can specify an underlying type.

The underlying type is limited to a strict set of built-in C# types: , so you cannot use a CTS type for it.

So you might think that you can only define enumeration values by integer constant like this:

namespace BeSharp
{
    enum TwoState
    {
        False = 0,
        True = 1,
    }
    enum ThreeState
    {
        False = 0,
        True = 1,
        Unknown = -1,
    }
}

Well, you can do it like this too, since Operations between different enum types are allowed in another enum declaration: Read the rest of this entry »

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, Development, Software Development | Leave a Comment »

.NET/C#: an alias is not the same as a synonym: int versus Int32, etc (fun with enums and aliases part 1)

Posted by jpluimers on 2014/01/28

I was amongst the C# programmers that believe the below table of C# integral types is an alias table. But it is not: it is a synonym table.

C# type .NET Framework Type/
Common Type System
byte System.Byte
sbyte System.SByte
short System.Int16
ushort System.UInt16
int System.Int32
uint System.UInt32
long System.Int64
ulong System.UInt64

You can use the common type system types as coding standard, or prefer the C# types. There are arguments for both.

I am still in the first group: prefer CTS types. They make changing between .NET languages a lot easier (C# and VB.NET are not the only .NET based CLI languages I use).

And indeed almost everywhere you can exchange the .NET Framework Type and the C# type without changing meaning.

There are two exceptions Read the rest of this entry »

Posted in .NET, C#, Delphi, Development, Jon Skeet, Software Development | 1 Comment »

Downloading https urls from the commandline through cURL for Windows

Posted by jpluimers on 2014/01/27

Lately I moved more and more away from wget, mainly because out of the box, wget (and also aria2, which I like for the bittorrent support) handle https downloads so badly: you need to manually setup your CA store on each and every installed system.

Not so with cURL, especially not on Windows any more, as “recently” (that is: since the last time I examined it, which is over a year ago now), there is a new kid in town: cURL for Windows: a Windows Installer for the Web Transfer Tool.

You don’t even need to download the installer. Grabbing the stuff from the bin directory in the zip download is enough: it contains a prepackaged CA certificate set that works splendid.

So now downloading https://dl.google.com/update2/installers/ChromeStandaloneSetup.exe to the current directory is as simple as Read the rest of this entry »

Posted in *nix, Batch-Files, Development, Power User, Scripting, Software Development, wget, Windows | Tagged: , | Leave a Comment »

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