Re: Problem about Properties - C# Discussion Boards

kcynic1-Aug-07 3:16

1-Aug-07 3:16

Yes,you are right,if you set the properties using codes it works well.But if I make a usercontrol and edit its properties in its container,there would be some wrong.
I had pasted my real codes in another thread.Would like to have a look?
Thanks

Re: Problem about Properties

collapo1-Aug-07 1:59

collapo

1-Aug-07 1:59

hi,

kcynic wrote:
public int A{
get{return this._A;}
set{if(vale<100/this._B)this._A=value;}
}

do you mean:

public int A {
get{return this._A}
set{if(value<(100/this._B))this._A=value}
}

or what?
I'm not sure about precedence, but if "<"'s is higher than "/" then the if returns false because value<100 can be (0 or 1 )/100 is 0 in int, so _A never gets a value.
I guess, you should check the condition.

Re: Problem about Properties

kcynic1-Aug-07 2:06

kcynic

1-Aug-07 2:06

I am sorry,I mean:
if(value<(100/this._B))

Thanks.But the source codes is like this,the problem is the same.

Re: Problem about Properties

Martin#1-Aug-07 2:04

Martin#

1-Aug-07 2:04

HEllo,

I think best practice would be implementing "System.ComponentModel.ISupportInitialize" in your control.

public class YourUserControl : System.Windows.Forms.UserControl, System.ComponentModel.ISupportInitialize

This interface has two methods:
BeginInit()
EndInit()

The designer will call the EndInit method at the end of InitializeComponets (means all the properties are set).

((System.ComponentModel.ISupportInitialize)(this.yourUserControl1)).EndInit();

Your UserControl just needs a boolean flag wich tells the properties when EndInit was called.
And as an init call a method which does the validation:

private bool initReady = false;

private int _aInt=0;
public int AInt
{
    get
    {
        return _aInt;
    }
    set
    {
        if(value!=_aInt)
        {
            _aInt= value;
            if(initReady)
            {
                DoStuffWithAandB();
            }
        }
    }
}

private int _bInt=0;
public int BInt
{
    get
    {
        return _bInt;
    }
    set
    {
        if(value!=_bInt)
        {
            _bInt= value;
            if(initReady)
            {
                DoStuffWithAandB();
            }
        }
    }
}

private void DoStuffWithAandB()
{
    if(AInt < BInt)
    {

    }
}

#region ISupportInitialize Member
public void BeginInit()
{
}

public void EndInit()
{
    initReady=true;
    DoStuffWithAandB();
}
#endregion

Hope it helps!

All the best,

Martin

Re: Problem about Properties

kcynic1-Aug-07 2:52

kcynic

1-Aug-07 2:52

I guess it will vety helpfull.But I am sorry that I am only a beginer from C++ to C#.
I come up such problem in my work.I need a usercontrol,I insert some properties to the control,but some properties could dependent on some others,like my real code(I paste it in anoter reply).

Thanks all the same,But would like to tell me if there is another way to do so?

Re: Problem about Properties

Martin#1-Aug-07 2:58

Martin#

1-Aug-07 2:58

Hello!

I don't think there is a nicer solution for that.
You would have to set a bool Flag for every property, to see if it was initialized.
Which is dirty, and if you use the "[DefaultValue(1)]" Attribute (which would be good practice, as it is not neccessary that the designer adds code for a property which doesn't change it's value), it would not work!

I would recommend to go threw my example again, add your validation from the setter of your property to the method, and call this method if the EndInit flag is true.

All the best,

Martin

Re: Problem about Properties

Luc Pattyn1-Aug-07 2:37

Luc Pattyn

1-Aug-07 2:37

kcynic wrote:
I find the properties of a class are set in name order

That is unknown to me. I have not seen it in the documentation, so I would
hesitate very much relying on it.

Anyhow, I fail to see where it is relevant to your code.
Both members _A and _B get initialized, there is no property involved in that.
If you now start using the properties, _A and _B have their values.

If you really have a problem, something going wrong give exact symptoms
(compile errors, run-time exceptions, or ist/soll values)

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

Re: Problem about Properties

kcynic1-Aug-07 2:46

kcynic

1-Aug-07 2:46

there is the real code:

namespace Test2
{
public partial class UserControl1 : UserControl
{
public UserControl1()
{
InitializeComponent();
}
private int m_xBlocks = 1;
public int xBlocks
{
get { return this.m_xBlocks; }
Confused | :confused:

set { if (value > 0) this.m_xBlocks = value; }
}
private int m_BarWidth = 10;
public int BarWidth{
get { return this.m_BarWidth; }
set{
Confused | :confused:

if (value > 0 && value < (100 / this.xBlocks))//or this.m_xBlocks
this.m_BarWidth = value;
}
}
}
}

Re: Problem about Properties

Luc Pattyn1-Aug-07 2:59

Luc Pattyn

1-Aug-07 2:59

That's a nice piece of code (it would even look better on this forum
when inside PRE tags).

Now how about "If you really have a problem, something going wrong give exact
symptoms (compile errors, run-time exceptions, or ist/soll values)" ?

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

Re: Problem about Properties

Malcolm Smart1-Aug-07 2:59

Malcolm Smart

1-Aug-07 2:59

Luc Pattyn wrote:
(compile errors, run-time exceptions, or ist/soll values)

What are ist/soll values?

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

Re: Problem about Properties

Luc Pattyn1-Aug-07 3:42

Luc Pattyn

1-Aug-07 3:42

ist is what it currently is, and soll is what it should be.
These are German terms, quite handy, and often used in some technical branches
(such as control engineering), no matter what language is being used.

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

Re: Problem about Properties

Malcolm Smart1-Aug-07 4:53

Malcolm Smart

1-Aug-07 4:53

Thanks.

They'll go into my next test plan...

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

Re: Problem about Properties

Scott Dorman1-Aug-07 13:38

Scott Dorman

1-Aug-07 13:38

What no one has pointed out is that it really isn't good practice to have properties that depend on the internal state of another property specifically for the reason that you can't control the order they will be set by the end user.

For what you are trying to do, using a method that takes 2 parameters would be better. Inside the method, you can set the internal variables in the correct order and then perform your calculations. If you still need access to the parameter values after the function exits, change the properties to read-only.

-----------------------------
In just two days, tomorrow will be yesterday.

http://geekswithblogs.net/sdorman

Re: Problem about Properties

kcynic2-Aug-07 18:27

kcynic

2-Aug-07 18:27

yes,perhaps should be.
But sometimes I really have to make some properties dependent on others.
For example,I am writing a 3-D bar chart component,the bar width would depend on block width of the x-aix(I mean that no matter how width the bar you set,it should not wider than the block width,but the block width even depend on the block count of the x-aix).
Thanks

Call To SNMP Device

kaushal6541-Aug-07 1:24

kaushal654

1-Aug-07 1:24

* I'm want to capture router information such as Incommming/Outgoing traffic, router up time, CPU utilization, Interface IP addresses, etc.
* I made a community in the router and try to get that information. But it not success.
* If anybody knows something about that pls reply me.
* If u have any C# code related that thing pls sent it.

Thanks..........

Problem printing images on Zebra Printer

Sharath Madhuranath1-Aug-07 1:22

Sharath Madhuranath

1-Aug-07 1:22

Hi,
I am working on a Zebra Printer (110XiIII Plus) and trying to print custom labels using a C# application, but am having no progress in printing graphics i.e. images. I am using the latest driver also.

I have a BMP file that needs to be printed. I tried to print using the PCX format, but even that didn't work.

I read in the documentation that the ~DY command can be used to send a bitmap to the printer and then recall it from the printer's memory and print it.But even that hasn't worked.

The command I am using is ~DYE:123.BMP,B,B,4096,,
Where 123.BMP is my file which is 13x13 and 4096 is the size in bytes. Is this correct or am i missing something or doing wrong!??

Any help is appreciated.

Regards
Sharath M

Re: Problem printing images on Zebra Printer

kubben1-Aug-07 2:01

kubben

1-Aug-07 2:01

First off Zebra printers are kind of a pain, but they do work pretty good. I guess my first question would be have you loaded the 123.bmp on the zebra printer? In my previous job, there was a lot of custom code to load all the images onto the zerbra so those commands would work. My current job, we use crystal reports and embed images into the report and that seems to work just fine.

Hope that helps.
Ben

How to optimize remove unused entries in resx ?

stancrm1-Aug-07 1:20

stancrm

1-Aug-07 1:20

Hello...

I have a resx file and that file has about 1000 entries.
Some entries are not used. How to find out, which entries are not used ?
Instead of search it manually using "Find All References".

Thanks...

run application ?

abcomp011-Aug-07 0:55

abcomp01

1-Aug-07 0:55

how run application(program) in task(background)
and how how close process program Blush | :O

Re: run application ?

kubben1-Aug-07 2:02

kubben

1-Aug-07 2:02

I think if you search on the Process object and process.Start(program) You will find all the info you need.

Hope that helps.
Ben

Adding TLB to - Debug\Interop ? ?

Yanshof1-Aug-07 0:51

Yanshof

1-Aug-07 0:51

I doing add reference to some TLB file and i see that in the C# project i have the tlb lib wrapped in some interop.

The problem is that the TLB does not show me all the interface that are in the TLB file.

Someone have solution ?

Thanks

Re:Disabling maximising form by doubleclicking on winform header

kyreddy1-Aug-07 0:36

kyreddy

1-Aug-07 0:36

Hi,
Can Anybody help me which API should i use to disable double clicking on window border.When ever we double click on the windows form header it will maximises the window at the top left corner of the desktop.I want to disable this Property for my window.

Any help will be greatly appreciated.

Re:Disabling maximising form by doubleclicking on winform header [modified]

Martin#1-Aug-07 0:58

Martin#

1-Aug-07 0:58

Hello,

kyreddy wrote:
which API should i use to disable double clicking on window border

No API needed!

Just override WndProc method like this:

const int WM_SYSCOMMAND = 0x112;
const int SC_MAXIMIZE2 = 0xF032;
protected override void WndProc( ref Message m )
{
    if( m.Msg == WM_SYSCOMMAND )
    {
        if( m.WParam.ToInt32() == SC_MAXIMIZE2 )
        {
            return;
        }
    }
    base.WndProc( ref m );
}

Hope it helps!

-- modified at 7:09 Wednesday 1st August, 2007

All the best,

Martin

Re:Disabling maximising form by doubleclicking on winform header

kyreddy1-Aug-07 2:26

kyreddy

1-Aug-07 2:26

Thank you very much Martin its working.

Re:Disabling maximising form by doubleclicking on winform header

Martin#1-Aug-07 2:27

Martin#

1-Aug-07 2:27

You are wellcome!

All the best,

Martin

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