services with gui - C# Discussion Boards

"Bad Form" to use public class variables without get & set?

ThomasH12-Aug-04 7:06

2-Aug-04 7:06

Hey everyone, just wondering what your thoughts are on Get & Set! I've got a class in which I have two public variables. The class itself changes their values, and any calling class can also change the values.

Is it "bad form" to just leave these variables public? Or should I turn these into class properties by doing:

private int _myvar;

public int myvar
{
  get
  {
    return _myvar;
  }
  set
  {
    _myvar = value;
  }
}

The class is so specialized that I don't need to do any checking during a "set" when I call the class methods. My instinct says that I'd get a microsecond or two of a performance boost by just leaving myvar as public, and eliminating the private/get/set/propery code. But I'm curious as if to this is bad form.

I could see if I had to prevent a "set" operation, or perform a check on the value first- but I don't have to do either of these.

Thanks!

-Thomas

Re: "Bad Form" to use public class variables without get & set?

Steven Campbell2-Aug-04 7:38

Steven Campbell

2-Aug-04 7:38

The main argument against public fields is one of compatibility. If you change the public field to a public property, then that is a breaking change.

So, probably not a big deal for monolithic single EXE apps, but for class libraries it is a no-no.

In C#, I usually just put the whole property on a single line -- that way it does not clutter up the code so much.

There is one (experimental) .NET language takes care of this more elegantly, called Boo. It uses attributes to let you mark a private field as having a getter and/or setter, which is then auto-generated at compile time (by the Boo compiler).

my blog

Re: "Bad Form" to use public class variables without get & set?

Judah Gabriel Himango2-Aug-04 8:05

Judah Gabriel Himango

2-Aug-04 8:05

Virtually all the .NET framework uses get/set properties, even for lightweight structs (Point, Size, Rectangle, for example).

The only times the framework exposes fields are static readonly fields; aside from that the standard seems to be to expose fields as properties.

Judah Himango

Re: "Bad Form" to use public class variables without get & set?

ThomasH12-Aug-04 9:16

ThomasH1

2-Aug-04 9:16

Steven & Judah, thanks! I guess I'll change those fields into properties- I hate "breaking style". The class is sealed- it's basically for some help during a system data migration- but as trivial as it is, I don't want any poor coding habits popping up!

-Thomas

Re: "Bad Form" to use public class variables without get & set?

Nemanja Trifunovic2-Aug-04 8:18

Nemanja Trifunovic

2-Aug-04 8:18

Steven Campbell wrote:
There is one (experimental) .NET language takes care of this more elegantly, called Boo. It uses attributes to let you mark a private field as having a getter and/or setter, which is then auto-generated at compile time (by the Boo compiler).

C++/CLI has something similar, called trivial properties. Basically, you say:

property int Something

and compiler creates a private variable and a property for you.

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

Re: "Bad Form" to use public class variables without get & set?

Nick Parker2-Aug-04 8:48

Nick Parker

2-Aug-04 8:48

Which in turn generate the appropriate get_x and set_x method calls.

- Nick Parker
My Blog | My Articles

How to change error icon shown in datagrid cells

Kasdoffe2-Aug-04 5:43

Kasdoffe

2-Aug-04 5:43

I want to be able to change the error icon shown in the datagrid cells on a per cell basis when i use the SetColumnError method.

For example, my application has errors and warnings. Errors prevent a user from saving any changes and warnings are only a visual indicator that the user needs to read.

I want to display the normal red error icon for errors, but want to display a different icon (a yellow error icon) on a warning.

How can I change this icon?

services with gui

elraton2-Aug-04 5:26

elraton

2-Aug-04 5:26

Hi.

I want to be able to configure and monitor what a service is doing on the fly, by means of a gui. I want the service to run as a normal service, but to allow an optional user interface.

Like the sygate firewall, for example.

How can I do this? should I use two different .exe? add a form into the service that is called when a user logs in?

Thanks

Re: services with gui

Colin Angus Mackay2-Aug-04 8:12

Colin Angus Mackay

2-Aug-04 8:12

Services should not contain GUI components. You should write a separate application for configuring the service, this application may have to communicate directly with your service or may just alter some centrally accessible configuration options somewhere (like a datbase or file).

"If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way!

Custom Control leaps to 0,0 on F5

ddelapasse2-Aug-04 5:26

ddelapasse

2-Aug-04 5:26

Help! I've created several custom controls, but I notice that when I layout several on a screen and hit F5 to enter the debugger, sometimes the last control created will leap up to 0,0 on the design grid. Actually, the application that is being debugged shows everything fine, but on the IDE's design screen the control has lost all its properties and been jerked up to the top left corner. It kind of looks like the control was deleted and put back at 0,0 without my intervention.

I don't know how to debug this since it seems to happen behind-the-scene and doesn't hit any breakpoints in my app. It's all fine until I exit the debugger and run again, but if I watch the IDE I see the control jump immediately when I hit F5. If anyone has seen anything like this please give me some insight into what I'm looking for and how to track it down.

After it does it once, I can move the control back and it's repeatable, but if I add/delete controls from the screen it stops repeating.

thanks!
Deanna

Problem with string.Replace() and antislashes...

polkiujhy2-Aug-04 4:58

polkiujhy

2-Aug-04 4:58

Hi,

I ve got a string containing ", and i have to replace it by \" before to send it as argument of an external program. So i use successfully the method replace:

request.Replace("\"", "\\\"");

But when i try to do the opposite with the reply, it doesn't work at all!!

reply.Replace("\\\"", "\""); // this don't do anything

If sombody has got an idea....

thks

SkN 0o.

Re: Problem with string.Replace() and antislashes...

Michael P Butler2-Aug-04 6:15

Michael P Butler

2-Aug-04 6:15

I tried this

string request = "\"Hello\" World";
Console.WriteLine(request);
request = request.Replace("\"", "\\\"");
Console.WriteLine(request);
string reply = "\\\"Hello World\\\"";
reply = reply.Replace("\\\"", "\"");
Console.WriteLine(reply);

And it worked fine. Of course, I hardcoded the strings. Are you sure the reply is coming back in the expected format?

Michael

CP Blog [^]

Custon TrackBar

Guinness4Strength2-Aug-04 4:11

Guinness4Strength

2-Aug-04 4:11

I'm sorry this question is so vague, but I'm not sure where to begin. I'm attempting to create a TrackBar from scratch. I'd like to implement rounded corners in both the borders of the TrackBar and the sliding user component of the control. Can anyone suggest where I can being researching how to create the rounded corners of the back ground ? I've started with a Panel control and created a rounded-corner rectangle bitmap as the Panel's background image. I think I'd have to use GDI to locate corners and set the color to Transparent or somthign like that, but again....I'm not sure. Any hints or idea on where I can start looking for the solution to my problem ?

Re: Custon TrackBar

leppie2-Aug-04 4:16

leppie

2-Aug-04 4:16

GraphicsPath will be friend Smile | :)

Dont bother with ANYTHING else! Unless u like pain and misery!

^{top secret xacc-ide 0.0.1}

Re: Custon TrackBar

Guinness4Strength2-Aug-04 9:22

Guinness4Strength

2-Aug-04 9:22

OK, Great advice leppie, I've created the shape I need, but I'm having trouble figureing out how to "capture" the exterior region of the control shape (i.e. outside my rounded rectangle)
I want to set the color of these four regions (each corner) to Color.Transparent, but I don't know how to identify these regions...any ideas ?

Re: Custon TrackBar

Guinness4Strength2-Aug-04 9:34

Guinness4Strength

2-Aug-04 9:34

I think I figured it out.

PropertyGrid

blankg2-Aug-04 2:03

blankg

2-Aug-04 2:03

I have a control which inherits from textbox and when i set the
PropertyGrid.SelectedObject to my control the property grid shows all the public properties which are inherited, how can i hide these properties ?
like hiding all the behavior attributes.
(without overriding all of them and setting [Browsable(false)] to each one)

Re: PropertyGrid

Nick Parker2-Aug-04 3:35

Nick Parker

2-Aug-04 3:35

blankg wrote:
(without overriding all of them and setting [Browsable(false)] to each one)

I don't belive you can do this without applying the Browsable attribute.

- Nick Parker
My Blog | My Articles

Xml Serialization and Interfaces...

mgaerber2-Aug-04 1:00

mgaerber

2-Aug-04 1:00

Hi I get an error when trying to serialize a derived class with XmlSerializer because it's base class implements an interface:

cannot serialize XXX because YYY is an Interface...

Any suggestions???

Re: Xml Serialization and Interfaces...

leppie2-Aug-04 1:03

leppie

2-Aug-04 1:03

specify the implemetation type in the XmlElementAttribute, u should have an attribute for every class that will be deserialized.

^{top secret xacc-ide 0.0.1}

Re: Xml Serialization and Interfaces...

mgaerber2-Aug-04 1:36

mgaerber

2-Aug-04 1:36

I don't want to serialize the base class stuff,
only the current instances 'as is' -

is there a way I can let the serializer ignore the inheritance?

Re: Xml Serialization and Interfaces...

leppie2-Aug-04 4:13

leppie

2-Aug-04 4:13

mgaerber wrote:
is there a way I can let the serializer ignore the inheritance?

You can ignore certian elements with attributes, but I suspect you havent done much reading on this, I suggest you do, unless u wanna write your own de/serializer. And no u can never instantiate an interface or an abstract class, so unless u wanna break .NET that will never succeed!

^{top secret xacc-ide 0.0.1}

Re: Xml Serialization and Interfaces...

mgaerber12-Aug-04 23:10

mgaerber

12-Aug-04 23:10

Alright,

the problem was in a class from which I inherited,
[XmlIgnore] did the trick...

Thanks for your hints!

Reflection and array´s...

Norman-Timo2-Aug-04 0:43

Norman-Timo

2-Aug-04 0:43

And here I´m again...

I have problems to get a specified Array Length from an assembly file.

First here is a extract from the assembly file (source):

public class SEGMENT_FLATNESS
{
public int ID { get{ return 221; } }

// date as 8-digit integer in format yyyymmdd
public int DATE;
// time as 6-digit integer in format hhmmss
public int TIME;
// test
public float[] FLATNESS;

public SEGMENT_FLATNESS ()
{
FLATNESS = new float[35];
}

}

To get the array length I tried following:
first I have ceated an instance from the upper class, then I got the related Field and tried to get the Property 'Length' from it.

The second way was to invoke the Method GetLength from the array, but both didn´t work.

Here my last try:

using System;

using System.Reflection;

namespace DummyTest
{
///

/// Summary description for Class1.
///

class Class1
{
///

/// The main entry point for the application.
///

[STAThread]
static void Main(string[] args)
{
Assembly testAss = System.Reflection.Assembly.LoadFrom("KorrektesFile");

Type testType = testAss.GetType("SEGMENT_FLATNESS");

object testInvoke = Activator.CreateInstance(testType);

FieldInfo testInfo = testType.GetField("FLATNESS");

Type fieldType = testInfo.FieldType; // weiß nicht ob das nötig ist

PropertyInfo p = fieldType.GetProperty("Length");

MethodInfo[] testMethodInfo = p.GetAccessors(false); //liefert nur die public get Methode für die Länge!!!

testMethodInfo[0].Invoke(testInvoke, null); // **************

string tmpString = testInfo.Name; //dummyZeile wg. debug (kein vorzeitiges Ende)
}
}
}

What did I wrong? And how can I get the array length?

Please help me...
Norman-Timo

Re: Reflection and array´s...

leppie2-Aug-04 1:01

leppie

2-Aug-04 1:01

Norman-Timo wrote:
testMethodInfo[0].Invoke(testInvoke, null);

if u want a value, u should assign it!

^{top secret xacc-ide 0.0.1}

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