C# Discussion Boards - CodeProject

4-Jan-04 19:01

C# - rather, the .NET base class library (BCL) - does not provide such features. This is much too low-level for the BCL. You'll have to P/Invoke native functions (see DllImportAttribute documentation for details). You should also try searching this site or googling the rest of the 'net for any examples.

-----BEGIN GEEK CODE BLOCK-----
Version: 3.21
GCS/G/MU d- s: a- C++++ UL@ P++(+++) L+(--) E--- W+++ N++ o+ K? w++++ O- M(+) V? PS-- PE Y++ PGP++ t++@ 5 X+++ R+@ tv+ b(-)>b++ DI++++ D+ G e++>+++ h---* r+++ y+++
-----END GEEK CODE BLOCK-----

One Line

eggie54-Jan-04 12:29

4-Jan-04 12:29

foreach(string message in mail.LIST())
    Console.WriteLine("S: "+message);

How can I get this to 1 line?

/\ |_ E X E GG

Christian Graus4-Jan-04 12:58

Christian Graus

4-Jan-04 12:58

in C++ you could do something like

for (int i = 0;i < mail.count(); i++, Console.WriteLine(mail.item(i)));

I dunno if C# supports the comma within a for loop.
You can also do this:

foreach(string message in mail.LIST()) Console.WriteLine("S: "+message);

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

eggie54-Jan-04 13:01

4-Jan-04 13:01

I guess I should mention that, LIST is an ArrayList.

/\ |_ E X E GG

Christian Graus4-Jan-04 13:06

Christian Graus

4-Jan-04 13:06

I thought it might be, but I was setting out to show the general syntax where a for loop would do what you want, not to write the specific code for you. Writing a for loop that actually does what you want should be a no brainer if the comma notation is supported.

BTW, I should mention that while I'll also often see how terse I can make my code, number of lines is not always an indicator of anything. Always consider before you make 6 lines of code into 2 if your code has become easier, or harder to read and maintain. Also, the shorter code does not necessarily run any faster, and may be slower.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

eggie54-Jan-04 13:42

4-Jan-04 13:42

excellent.

/\ |_ E X E GG

Heath Stewart4-Jan-04 18:51

4-Jan-04 18:51

And obfuscating your code like that doesn't compile any differently. There is no difference between

foreach (...) doSomething();

foreach (...)
  doSomething();

foreach
  (...
    )
 
 
doSomething();

It's all syntactically the same and the compiler doesn't care. As Christian said, it's all a matter of readability. So long as you uphold the language specification, it doesn't really matter how you format your source code (unless you're one of those pseudo-languages like VB).

eggie55-Jan-04 11:51

DateTime Property, custom TypeConverter for XmlSerialisation ?

5-Jan-04 11:51

Ahh, you see... I didn't know that. I read this C# book and it told me that if I didn't want to use the {}'s on my loops I had to put the doSomething() right under the loop statment. EXACTLY ONE LINE DOWN. I never tried putting it anywhere else, I just though it was the rule.

That's cool, I know that know. Thanks for the incite.

/\ |_ E X E GG

Chris Richner4-Jan-04 11:56

Re: DateTime Property, custom TypeConverter for XmlSerialisation ?

4-Jan-04 11:56

Hi,

my class has a DateTime property. I would like to use the XmlSerializer and the DateTime Property should be written in RFC 822 format.

I guessed i can implement a typeconverter which can convert between DateTime and string (RFC822). But it seems like my typeconverter is never called.

[System.ComponentModel.TypeConverter(typeof(DateTimeRFCConverter))]
public DateTime PubDate
{get;set;}

is my idea basically wrong or did i missed something? Why use the XmlSerializer the DateTime typeconverter instead of my TypeConverter?

Thanks

.:[Greetz from Jerry Maguire]:.

Heath Stewart4-Jan-04 18:46

Re: DateTime Property, custom TypeConverter for XmlSerialisation ?

4-Jan-04 18:46

XML serialization doesn't make use of a TypeConverter. It is hard-coded to format the intrinsic types and several common types like a DateTime. You could instead implement the IXmlSerializable interface. Though it's undocumented, it's pretty easy to figure out. Otherwise, you could create your own XmlSerializationReader and XmlSerializationWriter, but both are also undocumented and very complex. I'd recommend implementing IXmlSerializable on your class that contains the DateTime you want to format differently.

Also, you could always have a public property that returns and accepts a string in the format you want. You could use XmlIgnoreAttribute on the actual DateTime proeprty while using the value from the string property:

[XmlRoot("example")]
public class Example
{
  // ...
  [XmlIgnore]
  public DateTime DT
  {
    get { return this.dt; }
    set { this.dt = value; }
  }

  [XmlElement("dt")]
  public string DTFormat
  {
    get { return this.dt.ToString("r"); }
    set { this.dt = DateTime.Parse(value); }
  }
}

Note, using the format specifier "r" in DateTime.ToString says that it outputs a date-time in RFC 1123, but this RFC is not found the the format looks the same. Use a custom format if I am wrong.

Chris Richner4-Jan-04 20:11

Re: DateTime Property, custom TypeConverter for XmlSerialisation ?

4-Jan-04 20:11

Hi Heath Stewart,

thanks, i guessed there is another way than implementing IXmlSerializable because everything works fine except the DateTime Frown | :(

this second property has to be public, right? Internal do not work.

.:[Greetz from Jerry Maguire]:.

Heath Stewart5-Jan-04 4:03

Re: DateTime Property, custom TypeConverter for XmlSerialisation ?

5-Jan-04 4:03

Yes, only public properties and fields can be serialized using XML serialization in .NET. You'll notice that I made my property public.

If you don't want the property to show up in the designer or in the code editor, just attribute it like so:

[Browsable(false)]
[EditorBrowsable(EditorBrowsableState.Never)]
[XmlElement("dt")]
public string DTFormat
{
  get { return this.dt.ToString("r"); }
  set { this.dt = DateTime.Parse(value); }
}

Chris Richner5-Jan-04 5:55

Re: DateTime Property, custom TypeConverter for XmlSerialisation ?

5-Jan-04 5:55

Hi Heath Stewart,

Good idea, but the important thing for me is that you do not see the property in intellisense. This confuse the developer Big Grin | :-D

.:[Greetz from Jerry Maguire]:.

Heath Stewart5-Jan-04 6:00

Re: DateTime Property, custom TypeConverter for XmlSerialisation ?

5-Jan-04 6:00

What do you think the EditorBrowsableAttribute is for?

Chris Richner5-Jan-04 8:52

Re: DateTime Property, custom TypeConverter for XmlSerialisation ?

5-Jan-04 8:52

hmmm, i guess for the properties (propertygrid)? Ok, i hit Ctrl+F1 and rtfm Smile | :)

Thanks

.:[Greetz from Jerry Maguire]:.

Heath Stewart5-Jan-04 9:53

5-Jan-04 9:53

The BrowsableAttribute keeps it hidden from the PropertyGrid (and any other component that honors this attribute). The EditorBrowsableAttribute hides it from the code editor. Reading documentation always helps. Smile | :)

List of ODBC DSN's

webdudeIA4-Jan-04 10:53

webdudeIA

4-Jan-04 10:53

I'm building an application that connects to SQL Server. I'd like to allow the user to choose one of their defined ODBC connections.

Does .NET provide any classes to assist with determining the system/user defined DSN's?

Coding in the heartland

Nick Parker4-Jan-04 11:25

Nick Parker

4-Jan-04 11:25

Yes, the ODBC DSN's are stored with the Windows registry. They are located in "LocalMachine\ODBC\ODBC.INI\ODBC Data Sources" and "CurrentUser\Software\ODBC\ODBC.INI\ODBC Data Sources" keys. There are many articles here on CP that discuss working with the registry under .NET. Does that help?

- Nick Parker
My Blog

webdudeIA4-Jan-04 13:18

webdudeIA

4-Jan-04 13:18

Thanks Nick.

I'll take a look at those.

Ron

Coding in the heartland

Nick Parker4-Jan-04 16:52

Nick Parker

4-Jan-04 16:52

Ron, where are you at in Iowa, I am near Des Moines.

- Nick Parker
My Blog