Datatable rows check - C# Discussion Boards

Re: DriveInfo - Removing a drive entry.

7-Jun-08 23:29

Looks okay in my opinion.

I would just exchange

if (drive.Name.StartsWith("C") && ignoreC == true)

with

if (ignoreC == true && drive.Name.StartsWith("C"))

This way StartsWith will only be executed when ignoreC is set to true. This is logically a bit more precise, but shouldn't make any difference in performance (unless your program runs on a pentium 80 Wink | ;)

)

regards

modified 12-Sep-18 21:01pm.

Jammer8-Jun-08 0:10

Jammer

8-Jun-08 0:10

That makes a stack of sense, thanks for that Greeeg. Glad it makes sense too, I was trying all sorts of different things in order to achieve this simplicity yesterday, nothing beats 'no code' to get 'nothing' done tho eh!

Wink | ;)

Jammer

Going where everyone here has gone before! Smile | :)

My Blog

Datatable rows check

NewToAspDotNet7-Jun-08 10:14

NewToAspDotNet

7-Jun-08 10:14

Hi All,
I have a datatable with some data :

ActivityNr ActivityStartTime ActivityDuration
001 20:30 00:30
002 20:30 00:40
003 20:40 00:30
004 20:50 00:30
005 20:55 00:30

As you can see, Activity 001 and 002 have the same StartTime(20:30), bud activity 002 has a longer Duration(40 minutes) then Activity 001(30 minutes).
Now i have to check all activities StartTimes and when they have the same StartTime(like 001 and 002), then i have to check the 'ActivtityDuration' of those Activities and delete the Activity with shorter duration from the datatable.
Assuming the datatable above, the end resulat most be:

ActivityNr ActivityStartTime ActivityDuration
002 20:30 00:40
003 20:40 00:30
004 20:50 00:30
005 20:55 00:30

001 is deleted because it had the same starttime as 002, bud a shorter duration.
Can anyone help me with this issue with some code ?

Thanx.

Re: Datatable rows check

Gareth H7-Jun-08 10:22

Gareth H

7-Jun-08 10:22

Pankach Udhas,

You need to create some DateTime objects and do some checks on them
Note: Its a better idea to use TryParse instead of Parse, i just used Parse because its faster to type out.

eg:

DateTime actOne = DateTime.Parse(actTwoDateTimeFromDataTable);
DateTime actTwo = DateTime.Parse(actTwoDateTimeFromDataTable);

if (actOne == actTwo )
{
 //we have the same StartTime
 DateTime actOneDur = DateTime.Parse(actOneDurationFromDataTable);
 DateTime actTwoDur = DateTime.Parse(actTwoDurationFromDataTable);

 if (actOneDur > actTwoDur)
 {
  //remove act2 
 }
 else
 {
  //remove act1
 } 
}

Does that help?

Regards,
Gareth.

(FKA gareth111)

Reflection or Serialization

sourceisnothere7-Jun-08 9:14

sourceisnothere

7-Jun-08 9:14

I want to build a small utility using c# where I have to construct a hash table from any given object's properties . Say for example if a class is something like this

namespace my.project
{
using System.Runtime.Serialization;
using System.Collections.Generic;

[Serializable]
public class A: MySuper
{
public A()
{
}

private int _id;
private string _name;
private B _b;

public int ID
{
get { return _id; }
set { _id = value; }
}

public string Name
{
get { return _name; }
set { _name = value; }
}

public B B
{
get { return _b; }
set { _b = value; }
}

............

Now the hashtable should be like

Key Value
-- -------
id 12
name Robert
ABid 11

BC[0]id 12 //in case b has a list of c and c has a property id
BC[1]id 14
..........
...........

I was able to construct the hash map using reflection for any simple objects like A having only name and id. But in real word A might have B and B might have a List of C. So I guess I have get the property value using recursion and reflection.

Can any one suggest a better way to crate the above hash table maybe using serialization.

Re: Reflection or Serialization

User 66587-Jun-08 9:51

Re: Reflection or Serialization

7-Jun-08 9:51

Serialization also uses Reflection internally to get the property information of a class, so you can just go the Reflection+Recursion route and everything will be fine.

This way you also don't have the limitations[^] of the standard .NET serialization classes.

modified 12-Sep-18 21:01pm.

sourceisnothere7-Jun-08 10:42

sourceisnothere

7-Jun-08 10:42

The problem I am having with reflection and recursion is I only need the string or primitive type's value. Now if its a B type object or a Collections.Generic.List then the the process gets really complicated.

I am right now trying to use

if(type is System.String) // not working
,,,,,,,,,,,,,,,,
else if(type is Userdefineobject) //how to get User define object?

So basically I need to differentiate betten the ones which are string, int (isPrimitive works but how can find which one are sting or list?)etc and the ones that are user define objects(B or C type in runtime) so that I can do some recursion.

An other image processing

Sajjad Izadi7-Jun-08 8:46

Re: An other image processing

7-Jun-08 8:46

hi again friends,
how can i change my image opacity?

User 66587-Jun-08 9:25

Re: An other image processing

7-Jun-08 9:25

One way would be to change the pixel format of the image to ARGB and then save it as PNG or TIFF file, like that:

public static Image SetImgOpacity(Image imgPic, float imgOpac)
{  
   Bitmap bmpPic = new Bitmap(imgPic.Width, imgPic.Height);
   Graphics gfxPic = Graphics.FromImage(bmpPic);
   ColorMatrix cmxPic = new ColorMatrix();
            
   cmxPic.Matrix33 = imgOpac;
            
   ImageAttributes iaPic = new ImageAttributes();
   iaPic.SetColorMatrix(cmxPic, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
   gfxPic.DrawImage(imgPic, new Rectangle(0, 0, bmpPic.Width, bmpPic.Height), 0, 0, imgPic.Width, imgPic.Height, GraphicsUnit.Pixel, iaPic);
   gfxPic.Dispose();
  
   return bmpPic;
}

using (Image img = Image.FromFile(filename))
{
   Image img2 = ((Bitmap)img).Clone(new Rectangle(0, 0, img.Width, img.Height), PixelFormat.Format32bppArgb);
   img2 = SetImgOpacity(img2, 0.5f);
   img2.Save(filename2, ImageFormat.Png);
   img2.Dispose();
}

I got the SetImgOpacity method from here[^]. I just tested this code and it works fine.

regards

modified 12-Sep-18 21:01pm.

Sajjad Izadi7-Jun-08 9:32

Re: An other image processing

7-Jun-08 9:32

you're really great, merci

User 66587-Jun-08 9:36

7-Jun-08 9:36

What I just tried out which works, you can also convert the image to grayscale with the ColorMatrix class used above, just set the matrix to

cmxPic.Matrix00 = 0.299f;
cmxPic.Matrix01 = 0.299f;
cmxPic.Matrix02 = 0.299f;

cmxPic.Matrix10 = 0.587f;
cmxPic.Matrix11 = 0.587f;
cmxPic.Matrix12 = 0.587f;

cmxPic.Matrix20 = 0.114f;
cmxPic.Matrix21 = 0.114f;
cmxPic.Matrix22 = 0.114f;

This will produce a grayscale image with a different approach as presented in the aricles.

Hope this helps Smile | :)

modified 12-Sep-18 21:01pm.

Image processing

Sajjad Izadi7-Jun-08 7:13

7-Jun-08 7:13

hi again friends,
i have an image and i want to make it white and black. how can i do that?
thanks

Kristian Sixhøj7-Jun-08 7:18

Kristian Sixhøj

7-Jun-08 7:18

Sajjad Izadi wrote:
i have an image and i want to make it white and black. how can i do that?

Do you mean programmatically?

If not, then this is the wrong forum, but you could use Photoshop or similiar to do that.

Kristian Sixhoej

"Failure is not an option" - Gene Kranz

Sajjad Izadi7-Jun-08 8:27

7-Jun-08 8:27

Yes

, what is the probloem?

User 66587-Jun-08 8:12

7-Jun-08 8:12

Here you go[^]

If you want to get in touch with image processing, then I also recommend the parts 2-5 from the series, they're really interesting and helpful.

regards

modified 12-Sep-18 21:01pm.

Sajjad Izadi7-Jun-08 8:34

7-Jun-08 8:34

your suggested project was great but what is the parts 2-5 from the series? please give some more explanation about them

User 66587-Jun-08 8:43

7-Jun-08 8:43

Part 1 - Per Pixel Filters[^]
Part 2 - Convolution Filters[^]
Part 3 - Edge Detection Filters[^]
Part 4 - Bilinear Filters and Resizing[^]
Part 5 - Displacement filters, including swirl[^]

Take a look at the pictures in the articles, then you'll see what the parts are about Smile | :)

modified 12-Sep-18 21:01pm.

Sajjad Izadi7-Jun-08 8:54

what is the current screen resolution?

7-Jun-08 8:54

that was again great, thank you

Sajjad Izadi7-Jun-08 5:55