Error in .NET (regions) ??!! - C# Discussion Boards

Roger CS4-Apr-03 3:41

4-Apr-03 3:41

I'm writing my first C# Windows Application using Win Forms. The program, a simple utility, is very processing intensive. Once the processing begins it continues for several minutes.

I need the program to process UI messages while it is processing data, obviously. I'm not sure how to do this using the runtime.

Would some kind person please point me in the right direction?

Roger

Re: Respond to UI Messages

neroknights4-Apr-03 4:06

neroknights

4-Apr-03 4:06

Well this involves some long explanation. It involves some windows understanding before you begin. What's important is that once the process is finished , it must call back on the windows message loop's main thread. I have the perfect article for you. Tale the time to read it. It's worth it.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnforms/html/winforms06112002.asp

Re: Respond to UI Messages

Nick Seng6-Apr-03 16:45

Nick Seng

6-Apr-03 16:45

My first thought would be to use the System.Threading class. Simply set you processing function as a thread and let it run simultaneously as your main thread.

Notorious SMC

The difference between the almost-right word & the right word is a really large matter - it's the difference between the lightning bug and the Lightning
Mark Twain

Get your facts first, and then you can distort them as much as you please
Mark Twain

Re: Respond to UI Messages

neroknights7-Apr-03 5:12

neroknights

7-Apr-03 5:12

The problem here is what happens if you want to be notified, when your thread is complete. That may be the case for many UI apps.

The article I have mentioned explains all this.

Cheers

Re: Respond to UI Messages

Nick Seng7-Apr-03 16:12

Nick Seng

7-Apr-03 16:12

Well, just add a MessageBox function add the end of the method that contains your process

Notorious SMC

Re: Respond to UI Messages

neroknights8-Apr-03 4:04

neroknights

8-Apr-03 4:04

Not exactly. Again, in most cases you want to do more than add a message box. Say for instance that when the process is finished, you want to write something to a textbox on that form. You MUST NOT update the textbox in the new thread. That is a no no in Windows. You must only update controls on the windows main thread (the win proc).

The article I've already mentioned explains all this. Take the time to read it, it's informative and it helped me alot as well. Smile | :)

Re: Respond to UI Messages

Nick Seng8-Apr-03 15:23

Nick Seng

8-Apr-03 15:23

Cool. Will look it up. Rose | [Rose]

Notorious SMC

Error in .NET (regions) ??!!

Wizard_014-Apr-03 3:38

Wizard_01

4-Apr-03 3:38

It is strange, anyone say : "it must be true", but .NET "no, rectangle isn't visible" !!!

RectangleF clippingRectangle = new RectangleF(0.0160072f,0f,0.002000898f,0.3201439f);
Region region = new Region(clippingRectangle);
bool success = region.IsVisible(new RectangleF(0,0,150,150)); // return false !!! Mad | :mad:

Have you idea how can I correct it ? Cry | :((

Please

Wizard_01

Re: Error in .NET (regions) ??!!

Chris Jobson4-Apr-03 10:57

Chris Jobson

4-Apr-03 10:57

I've found by experiment that the problem is with the width (0.002...). If either the width or the height of the rectangle used to create the region is less than 0.03125 then the problem occurs. I've also found that
region.IsEmpty(myform.CreateGraphics())
returns true if either the width or height is less than this value.

I'm afraid I've no idea why a width/height of less than 0.03125 makes a region empty, or what you can do about it (except check for a size less than this and make it bigger). 0.03125 = 1/32, so maybe this is some "magic number" used within GDI+? Confused | :confused:

Chris Jobson

Re: Error in .NET (regions) ??!!

Wizard_014-Apr-03 21:58

Wizard_01

4-Apr-03 21:58

Ohhh

I use this for zoom in/out in my new control. (I was so lazy to recalculate everytime when zoom has changed cell-region and rectangle to new values)

Maybe it necessery Cry | :((

but slower

Do you know how can I region flow by 1 pixel ? (I can be enoght in this case for me Smile | :)

)

Thank you ... Wink | ;)

Wizard_01

Types and XML

Jon Newman4-Apr-03 3:17

Jon Newman

4-Apr-03 3:17

Right. As a feature in my Animation engine, I want to be able to read an XML file for frame information.
In the engine I have an enum for storing specific types of frames.

For example one being for where the bitmap of the frame is stored.

public enum BitmapLocations
{
   InExe,
   Filesystem
}

Now, I have a dataset for reading an XML file into. I can cast any standard types easily. Such as:

(string)row["name"]

But when it comes to this enum value, I keep getting an invalid cast exception. I've tried:

XML:
<location>InExe</location>

C#:
(BitmapLocation)row["location"]

And this throws the exception.

I've also tried assigning the enum values to a number and using that instead, but still no luck.

Any ideas?

"If you just say porn then you get all manner of chaff and low grade stuff."
- Paul Watson, Lounge 25 Mar 03
"But a fresh install - it's like having clean sheets"
- C. Maunder Lounge 3 Mar '03

Jonathan 'nonny' Newman
Homepage [www.nonny.com] [^]

Re: Types and XML

Stephane Rodriguez.4-Apr-03 6:46

Stephane Rodriguez.

4-Apr-03 6:46

BitmapLocations dummy = BitmapLocations.InExe; // dummy assignment, does not matter

String s = "Filesystem";

// convert string to enum
BitmapLocations bl = (BitmapLocations) Enum.Parse(dummy.GetType(), s);

Have components you want to sell?

Roger Alsing4-Apr-03 0:57

Roger Alsing

4-Apr-03 0:57

Hi,
We are soon going to start to distribute .NET components/controls.
If you have something for .NET you think could be sold please contact us at info[at]compona.com for more info.

//Roger

Using the capacity property of ArrayList

Alex Iagovsky4-Apr-03 0:51

Alex Iagovsky

4-Apr-03 0:51

Hey .
As I understood , this property , if set explicitly , should
disable the autmatically expantion of the array when using "Add" ,when the Count equals to Capacity ..

well .. this doesn't work for me .

I just don't want the ArrayList to be expanded automatically when adding item , when Count equals to Capacity.

instead I'd expect that it will raise some exception .

of course I can do all that in my own class that using the ArrayList , but
I'd like that to be done in ArrayList itself .

anyone knows how to do it ?

Alex
ICQ : 10676475
email : alexyag@inter.net.il
===================================================
"The harder you fall, the higher you bounce." - American Proverb

Re: Using the capacity property of ArrayList

Paul Riley4-Apr-03 1:56

Paul Riley

4-Apr-03 1:56

I'm pretty sure Capacity just pre-assigns the memory, so if you have 5 items and a capacity of 10 then it's holding on to the memory for the other 5. But then when you put the 11th item in, your Capacity is increased to 11.

What do you actually want to do when item 11 is added?

Paul
We all will feed the worms and trees
So don't be shy - Queens of the Stone Age, Mosquito Song

Re: Using the capacity property of ArrayList

Stephane Rodriguez.4-Apr-03 6:51

Stephane Rodriguez.

4-Apr-03 6:51

Paul Riley wrote:
I'm pretty sure Capacity just pre-assigns the memory

Yes.

public virtual void System.Collections.ArrayList.set_Capacity(int value) {
  object[] local0;

  if (value != (int) this._items.Length) {
    if (value < this._size)
      throw new ArgumentOutOfRangeException(...);
    if (value > 0) {
      local0 = new Object[checked((uint) value)];
      if (this._size > 0)
        Array.Copy(this._items, 0, local0, 0, this._size);
        this._items = local0;
        return;
    }
    this._items = new Object[16];
  }
}

Re: Using the capacity property of ArrayList

neroknights4-Apr-03 4:01

neroknights

4-Apr-03 4:01

You can fix the size of the ArrayList like so ...

// Creates and initializes a new ArrayList.
ArrayList myAL = new ArrayList();
myAL.Add( "The" );
myAL.Add( "quick" );
myAL.Add( "brown" );
myAL.Add( "fox" );
myAL.Add( "jumped" );
myAL.Add( "over" );
myAL.Add( "the" );
myAL.Add( "lazy" );
myAL.Add( "dog" );

// Create a fixed-size wrapper around the ArrayList.
ArrayList myFixedSizeAL = ArrayList.FixedSize( myAL );

An exception will be thrown whenever yuo add or remove an item from
the array. However, you can modify the items currently in myFixedSizeAL. Smile | :)

SQL Server -> trigger -> event -> caught by C# program

zoltan_ie4-Apr-03 0:22

zoltan_ie

4-Apr-03 0:22

In SQL Server is it possible to have a trigger that will throw an event which could be caught by C# program running in the back ground?

Is this even possible? If it is, have u any links to help/examples?

a better description of the problem...

What I want to happen is that when we import data in to our database
(INSERT) that a trigger is called.

The trigger passes that data into a validation tool that cleans that
data and writes it back to a new clean database.

There needs to be two tables, one containing the raw original data and
one containing the cleaned up data.

The reason this is not done using a program to load the data is to
ensure any data loaded in to the database is cleaned.

Tommy

Array.Contains

Anonymous3-Apr-03 23:22

Anonymous

3-Apr-03 23:22

Hello,

does anybody know a way to find out if the following array
contains a certain element without iterating through it?

int[] arr = {1,3,5,7...};

Thanx in advance...

Brian

Re: Array.Contains

Paul Riley4-Apr-03 1:57

Paul Riley

4-Apr-03 1:57

Array.IndexOf

Paul
We all will feed the worms and trees
So don't be shy - Queens of the Stone Age, Mosquito Song

Re: Array.Contains

Anonymous4-Apr-03 2:23

Anonymous

4-Apr-03 2:23

It works, many thanks...

ddrk3-Apr-03 22:34

ddrk

3-Apr-03 22:34

Dear all:
I would like to register personal protocol the same as http.

what I want is the look and feel the same as http, you know, the richtextbox support such protocol, while you typing http://w3c.org, then a link wa shown.
I do not want to use ole to solve this.

Re: register customized protocol

Stephane Rodriguez.4-Apr-03 7:00

Stephane Rodriguez.

4-Apr-03 7:00

Lookup CodeProject for an auto-fill combo[^] article.

Re: register customized protocol

ddrk4-Apr-03 17:18

ddrk

4-Apr-03 17:18

thanks lot

Printing > How do I see the status of a printer

Leon van Wyk3-Apr-03 22:25

Leon van Wyk

3-Apr-03 22:25

I need to be able to see the status a printer ie. Paper Jammed, On-Line, Off-Line etc. but have got no idea were to start looking?

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.