C# Discussion Boards - CodeProject

Stefan Troschuetz15-Dec-04 2:23

15-Dec-04 2:23

Of course it doesn't, cause as MSDN states: "This timer is optimized for use in Windows Forms applications and must be used in a window." or "It requires that the user code have a UI message pump available".
So always read the documentation thoroughly, cause almost every information needed is written down there Smile | :)

www.troschuetz.de

Re: Timer in Win Service not Ticking

thuchv8714-Sep-10 21:28

thuchv87

14-Sep-10 21:28

You're using System.Windows.Forms.Timer. It has no use in Windows Service.
Using System.Timers.Timer class instead.
You must also change Timer_Tick eventhandler by Timer_Elapsed eventhandler
That's so simple!
Good luck!

GDI+ VS DirectX

G.Ringbom15-Dec-04 1:25

G.Ringbom

15-Dec-04 1:25

I have started doing some research for a relational database modeller. For this I'm gonna need the application to be able to do some drawing. I have been testing some simple things with GDI+ but I started thinking about the possibility of using managed DirectX.
What do you think, would I get a performance gain by using DirectX compared to using regular GDI+? Or maybe DirectX would put a too high system requirement for just using the application.

Re: GDI+ VS DirectX

Daniel Turini15-Dec-04 1:40

Daniel Turini

15-Dec-04 1:40

G.Ringbom wrote:
What do you think, would I get a performance gain by using DirectX compared to using regular GDI+?
Yes, but developing the UI will be much harder. DirectX is really targeted at easing game development, not easing UI development.
For a DB modelling tool, I can't see why you would need high frame rates. GDI+ is more than capable of drawing complex screens at decent speed for an editor.
As an example, I created recently a graphical editor for a rule engine, all done in C# (with a few P/Invoke calls) and the speed is very good on an old test machine (AMD 650MHz - 256MB RAM - PCI Riva TNT2 card) that we have here. Even on the biggest files, it's very usable.

Yes, even I am blogging now!

Re: GDI+ VS DirectX

Alex Korchemniy15-Dec-04 7:34

Alex Korchemniy

15-Dec-04 7:34

Daniel is right. Even programs like Visio use GDI

This posting is provided "AS IS" with no warranties, and confers no rights.

Alex Korchemniy

Re: GDI+ VS DirectX

Andres Coder15-Dec-04 10:03

Andres Coder

15-Dec-04 10:03

As an alternative, you *could* use Avalon instead. It's (should be) easy to use and has power of DirectX (it's based on it). This has, however, several drawbacks:
1. Development difficulties (You must own Whidbey and Avalon/WinFX CTP disc).
2. Release difficulties (you can't release your application until Avalon/WinFX is officially released (for Longhorn and XP).
3. High-spec client-machine needed as Avalon tends to need quite a machine (1 GHz processor, 256 MB Ram, DirectX 9 supporting video card and so on) though you can setup Avalon to work on a low-end machine, too.

Loop through Error

Vector715-Dec-04 0:34

Vector7

15-Dec-04 0:34

try
{
some code
}
catch(Exception ex)
{
some code
}

How can I loop with "forEach" statement through all exceptions ?

Re: Loop through Error

spif200115-Dec-04 0:54

spif2001

15-Dec-04 0:54

???

a catch block only catches one Exception. Why do u whant to loop and where?

I don't understand your request

spif2001

Re: Loop through Error

Vector715-Dec-04 1:11

Vector7

15-Dec-04 1:11

Hi,

Here is one example for SQLError

try
{
some code
}
catch(SqlException ex)
{
foreach(SqlError sqlError in ex.Errors)
{
some code
}
}

Sometimes you get more than one exeption at the same time ( especially SQL for example )

Re: Loop through Error

DavidNohejl15-Dec-04 1:23

DavidNohejl

15-Dec-04 1:23

hi,
As was already mentioned, catch "catches" only one Exception. I think you are trying to do something like :

<br />
try<br />
{<br />
 //some code<br />
 if(stg)<br />
 {<br />
  myBadFunctionThrowsMySpecificExcpetion();<br />
 }<br />
 else<br />
 {<br />
  i= i/0; // throws another exception<br />
 }<br />
}<br />
catch(MySpecificException ex)<br />
{<br />
 // handle my specific exception<br />
}<br />
catch(Exception ex)<br />
{<br />
  // handle generic exception (in this case divide by zero)<br />
}<br />

When exception is raised in try block, it is catched in "closest" catch if throwed exception is (in meaning that operator is would return true - same type or derived class) the same as declared in catch block. If exception of diferent type is thrown, then it passes thru first catch block to another (if present),.. etc. You must write catch blocks from specific to most generic; if you wrote catch for System.Excpetion first, all exceptions would be handled in this block. No other would have chance to trap error.

I only hope this is answer to your question Smile | :)

best regards,
David 'DNH' Nohejl

Never forget: "Stay kul and happy" (I.A.)

Re: Loop through Error

Vector715-Dec-04 1:50

Vector7

15-Dec-04 1:50

You are close to the problem, but i want get all error messages from all risen errors there. In the last message I have wrote an example for SQL tasks. Here it works, because you can assign a specific error, so I think it shpuld be possible to loop within all possible errors ( I need the name for the element and elements-> foreach(element in elements))

Re: Loop through Error

J4amieC15-Dec-04 3:36

J4amieC

15-Dec-04 3:36

how about:

try
{
   // something error prone
}
catch(Exception e)
{
   Exception ex = e;
   while(ex != null)
   {
       Console.WriteLine(ex)
       ex = ex.InnerException;
   }
}

popup with textbox

hornox14-Dec-04 23:55

hornox

14-Dec-04 23:55

Hi,

A question:

How can I create a popup with a textbox or a combobox in it?

e.g. in MS Access 2003 there is such a thing if you do
a right click on a table column to add a filter...

Thanks in advance!
Hornox

Re: popup with textbox

Stefan Troschuetz15-Dec-04 2:09

Stefan Troschuetz

15-Dec-04 2:09

Don't know if the following will work, but maybe you'll give it a try.

Create a simple Form, which contains the TextBox, ComboBox or whatever you want.
Catch the MouseDown or MouseUp event of the controls ,which should open the popup form after a right-click on them, and determine whether the right button was clicked.
If so create an instance of your form, assign the mouse coordinates to the Location property of your form and show it.

www.troschuetz.de

UI Thread in C#

Member 1697714-Dec-04 23:33

Member 16977

14-Dec-04 23:33

Hi All,

How to spawn a UI Thread in C#.
I want to show window having ProgressBar while starting application(from main window constructor),application takes some time to start.
The window having progressbar should run in different thread having it's own message que and all.

Thanks
TusharM.

Re: UI Thread in C#

Paul Watson15-Dec-04 0:24

Paul Watson

15-Dec-04 0:24

Maybe try it the other way around. You have a "splash" type screen which is your main constructor. It can load fast as it is small. It fires off a thread that starts the loading of the main app which uses delegates or some such to report back on the loading progress.

Here is an article that may help you out; A Pretty Good Splash Screen in C#

regards,
Paul Watson
South Africa

The Code Project

Re: UI Thread in C#

lesnikowski15-Dec-04 11:55

lesnikowski

15-Dec-04 11:55

You can use Application.Run more then once in an Application.

Try creating new splash form, pass it to Appication.Run method
then run your main form (Application.Run(new MainForm());)

When you need to close the splash screen just close the splashForm
(splashForm.BeginInvoke(new MethodInvoker(splashForm.Close));)

Please help me sending and recieveing message

arus200414-Dec-04 23:16

arus2004

14-Dec-04 23:16

Hi I have created a dll in vc++ 6.0 from where i want to send a specific message to my c# application and than want to handle that event in my c# front end

further i am also using that dll in a web seb service in c# that is used in an interface developed in vb.net.
is it possible to send my custom message from vc++6.0 dl to c# web service.
Waiting for ur responce
Thanks.

Custom Control problem

spif200114-Dec-04 22:06

spif2001

14-Dec-04 22:06

I have made a Custom Control and I'm having troubles in design time - I have omitted the Dispose method to the ABox in the code below.

Using the following code in design time (adding an ABox to a Form), i can change the MyComp.MyText property in the property editor and the Text property on my ABox will change.

But I can't change the MyComp.MyList property and make it change the ABox' Items values. It works in RunTime but not in design time.

How come?

Any and all ideas would be very welcome.

spif2001

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;

namespace AgroTest
{
public class ABox : System.Windows.Forms.ComboBox
{
private System.ComponentModel.Container components = null;
private MyComp myComponent;

public ABox()
{
InitializeComponent();
this.myComponent = new MyComp(this);
}

[Category("AgroTest"), System.ComponentModel.DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
public MyComp MyComponent
{
get
{
return this.myComponent;
}
}

private void InitializeComponent()
{
components = new System.ComponentModel.Container();
}
}
}

using System;
using System.ComponentModel;
using System.Windows.Forms;
using System.Collections.Specialized;

namespace AgroTest
{
[TypeConverterAttribute(typeof(ExpandableObjectConverter))]
public class MyComp
{
private ABox owner;
private StringCollection myList = new StringCollection();
private string myText = "!!";

internal MyComp(ABox owner)
{
this.owner = owner;
}

[Editor("System.Windows.Forms.Design.StringCollectionEditor, System.Design",
typeof(System.Drawing.Design.UITypeEditor)),
DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
DefaultValue(false)]
public StringCollection MyList
{
get{return this.myList;}
set
{
try
{
this.owner.Items.Clear();
foreach(string s in value)
{
this.owner.Items.Add(s + "!!");
}
this.owner.Invalidate();
this.myList = value;
}
catch(Exception){}
}
}

[DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
DefaultValue(false)]
public string MyText
{
get{return this.myText;}
set
{
try
{
this.owner.Text = value;
this.owner.Invalidate();
this.myText = value;
}
catch(Exception){}
}
}
}
}

Re: Custom Control problem

manivannan.p15-Dec-04 4:48

manivannan.p

15-Dec-04 4:48

Hi,

Try calling the InValidate() method, even after you set the value in the property.ie,

In "public StringCollection MyList" and "public string MyText", in the set block , call Invalidate after u set the value to MyText.

Try this and let me know...

Regards,
Manivannan

Re: Custom Control problem

spif200115-Dec-04 20:00

spif2001

15-Dec-04 20:00

Sadly it had no effect - thanks though Smile | :)

DataGrid in C#

frostbyte114-Dec-04 22:04

frostbyte1

14-Dec-04 22:04

Hi i'm new to C# and i'm trying to create a telephone Call Record on a datagrid but i couldn't get anything displayed on my datagrid. Though i assigned my datasource to be my call records. I was just wondering if anybody can give me a little lecture on datagrids.
Thanks.

Re: DataGrid in C#

Gavin Jeffrey15-Dec-04 1:12

Gavin Jeffrey

15-Dec-04 1:12

Could you post some code as to how you are assigning the datasource? Is this a windows form app or a web app?

change Regional Settings in C#

Kyaw Soe Khaing14-Dec-04 21:45

Kyaw Soe Khaing

14-Dec-04 21:45

I want to get and set ShortDate format from control pannel setting.how can i do in C#.
Pls answer me.

Re: change Regional Settings in C#

Paul Watson15-Dec-04 0:32

Paul Watson

15-Dec-04 0:32

I can only point you in the vague direction of the Globalisation namespace of .NET. This article mentions changing the CulterInfo (which is what you want) of a thread.

regards,
Paul Watson
South Africa

The Code Project

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