C# Discussion Boards - CodeProject

Re: I do not understand why the error ! :S

Not Active1-Jun-11 2:59

1-Jun-11 2:59

Well as the error indicates the connection is still opened from a previous attempt or some other method.

Since you are not using any try/catch blocks the code could have failed at any point between the Open and Close calls thus leaving the connection open.

Make use of the using statement

using(SqlConnection conn = new SqlConnection("..."))
{
  using(SqlCommand cmd = new SqlCommand("...", conn))
  {
    // Do actions here
  }
}

With this the connection and command will be disposed of regardless of whether a failure has occurred.

You should learn to program defensively also.

if(conn.State != ConnectionState.Open)
  conn.Open();

And lastly, use parameterized queries rather than concatenate a string for the command.

I know the language. I've read a book. - _Madmatt

modified on Wednesday, June 1, 2011 9:34 AM

Re: I do not understand why the error ! :S

ismail201-Jun-11 3:05

ismail20

1-Jun-11 3:05

which should help me get the line?

Re: I do not understand why the error ! :S

Not Active1-Jun-11 3:21

Not Active

1-Jun-11 3:21

What?????

I know the language. I've read a book. - _Madmatt

Re: I do not understand why the error ! :S

ismail201-Jun-11 3:29

ismail20

1-Jun-11 3:29

which line is wrong in my code?

Re: I do not understand why the error ! :S

Not Active1-Jun-11 3:32

Not Active

1-Jun-11 3:32

All of it. Please read the suggestions you have been given

I know the language. I've read a book. - _Madmatt

Re: I do not understand why the error ! :S

ismail201-Jun-11 3:34

ismail20

1-Jun-11 3:34

I can not see the error.

Re: I do not understand why the error ! :S

Not Active1-Jun-11 3:38

Not Active

1-Jun-11 3:38

Then we can't help you further

I know the language. I've read a book. - _Madmatt

Re: I do not understand why the error ! :S

BobJanova1-Jun-11 4:12

BobJanova

1-Jun-11 4:12

good one

Re: I do not understand why the error ! :S

Pete O'Hanlon1-Jun-11 3:25

Pete O'Hanlon

1-Jun-11 3:25

As others have said, your connection is open already. You could wrap the line c.Open() with

if (c.ConnectionState != ConnectionState.Open)
  c.Open();

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Re: I do not understand why the error ! :S

ismail201-Jun-11 3:33

ismail20

1-Jun-11 3:33

error http://www.imageupload.org/?d=FA9F79481[^]

Re: I do not understand why the error ! :S

Not Active1-Jun-11 3:37

Not Active

1-Jun-11 3:37

We are here to help but you must also put forth some effort. Copy & Paste is not a valid coding technique. You need to understand the objects you are working with. This error is very easily corrected by simply using the Intellisence built in to Visual Studio.

I know the language. I've read a book. - _Madmatt

Re: I do not understand why the error ! :S

ismail201-Jun-11 3:44

ismail20

1-Jun-11 3:44

if (c.State != ConnectionState.Open)
c.Open(); ---- accept that this code ***** but "c.ConnectionState" wrong

Re: I do not understand why the error ! :S

Pete O'Hanlon1-Jun-11 3:54

Pete O'Hanlon

1-Jun-11 3:54

For goodness sake, I just typed into the textbox here. I'm not opening things up in Visual Studio and creating a whole project just to test things for you.

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Logical issue with a recursive function call

John-ph1-Jun-11 2:23

John-ph

1-Jun-11 2:23

trying to figure out a way to get it right...

1. items in a collection fall in one of the category parent or orphan
2. items in a collection may have one or more independent parent / one or more orphan
3. Both (Parent and Orphan) may or maynot have Individual behaviour
4. If a parent has one or null behaviour it should be applied to children. Individual behaviour of children item be hidden
5. If a orphan has one or null behaviour it should be applied to it
6. An item will have only one or null behaviour

trying to rephrase the following code...

private static void ApplyBehaviour(IEnumerator items, Behaviour behaviour = null)  
        {
	        while(items.MoveNext())
		        {
			        ItemModel item = (ItemModel)items.Current;
		
			        if(item.type = parent)
			        {
				        parentModel parentModel = (parentModel)item;
				
				        if(parentModel.HasBehaviour)
				        {
					        behaviour = parentModel.Behaviour;
				        }
				
				        ApplyBehaviour(parentModel.Children.GetEnumerator(), behaviour);
	                                 
                                         if(parentModel.HasBehaviour)
				        {
					        behaviour = null;
				        }
			        }			
			
			        item.Behaviour = behaviour;
		        }
	        }
        }

inital call will be ApplyBehaviour(items);

if two items with common parent and different behaviour, then the above code gets the
first item and children right...takes the parent behaviour but the second item retains its behaviour and applie it to children.
not sure whether i have explained in a way that someone can read and understand

- Regards -
J O N

A good thing is a bad thing if it keeps you from the best thing. - Dr. Adrian Rogers

modified on Wednesday, June 1, 2011 8:37 AM

Re: Logical issue with a recursive function call

dasblinkenlight1-Jun-11 5:37

dasblinkenlight

1-Jun-11 5:37

It looks like the problem is that once you finish the first sibling with custom behaviour, you reset the value of behaviour to null. In other words, the logic as coded starts ignoring the value passed in after discovering the first sibling with parentModel.HasBehaviour == true.

Changing the code as follows avoids this problem:

if(item.type = parent) {
    ParentModel parentModel = (parentModel)item;
    ApplyBehaviour(
        parentModel.Children.GetEnumerator()
    ,   parentModel.HasBehaviour ? parentModel.Behaviour : behaviour
    );
}

Memory expensive rubber band selection?

Chesnokov Yuriy31-May-11 23:10

Chesnokov Yuriy

31-May-11 23:10

What is the reason of memory consumption in the DrawRoi function leading to hundreds of Mb?

There is a Frame bitmap and its FrameWithRoi copy to assign to PictureBox.
On the mouse move event new ROI coords are estimated and DrawRoi() is called.

DrawRoi()
{
RectangleF roi = Roi;                               

RectangleF rect = new RectangleF()
{
        X = (float)Frame.Width * roi.X,
        Y = (float)Frame.Height * roi.Y,
        Width = (float)Frame.Width * roi.Width,
        Height = (float)Frame.Height * roi.Height
};

// draw roi if it is smaller than the whole image
if (rect.Left > 0 || rect.Right < (float)FrameWithRoi.Width ||
    rect.Top > 0 || rect.Bottom < (float)FrameWithRoi.Height)
{
        Graphics g = Graphics.FromImage(FrameWithRoi);
        g.DrawImage(Frame, 0, 0);
        using (Bitmap region = new Bitmap(FrameWithRoi.Width, FrameWithRoi.Height, FrameWithRoi.PixelFormat))
        {
                Graphics roi_g = Graphics.FromImage(region);
                roi_g.FillRectangle(new SolidBrush(Color.FromArgb(64, 0, 0, 0)), new Rectangle(0, 0, FrameWithRoi.Width, FrameWithRoi.Height));
                roi_g.FillRectangle(new SolidBrush(Color.Red), rect);
                region.MakeTransparent(Color.Red);
                g.DrawImage(region, 0, 0);
        }
}                

this.framePictureBox.Image = FrameWithRoi;
}

Чесноков

Re: Memory expensive rubber band selection?

BobJanova31-May-11 23:36

BobJanova

31-May-11 23:36

Two things strike me immediately:
- you are not disposing of the graphics objects you obtain. This might actually be a resource leak.
- you create a new RectangleF every time (though I think this is a value type, so it shouldn't matter).

It's also possible that the bitmap doesn't get garbage collected immediately, even though it is being disposed of at the end of the using. But it should do.

Re: Memory expensive rubber band selection?

Chesnokov Yuriy1-Jun-11 0:42

Chesnokov Yuriy

1-Jun-11 0:42

Yes, disposing graphics objects solved the problem.
But why the drawing is very slow? The larger the image the slower update.

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Re: Memory expensive rubber band selection?

Luc Pattyn1-Jun-11 0:42

Luc Pattyn

1-Jun-11 0:42

Graphics objects are expensive, and you should dispose them. Why not use a using statement, just like you did for the region Bitmap?

And why would you need two Graphics instances, and a DrawImage()? Couldn't you just use the Bitmap(Image) constructor, and have its Graphics, just the one?

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Please use <PRE> tags for code snippets, they improve readability.
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Re: Memory expensive rubber band selection?

Chesnokov Yuriy1-Jun-11 0:56

Chesnokov Yuriy

1-Jun-11 0:56

I was looking for a way to darken non ROI region in the image.
You optimizations would be welcomed.

Why the picture box update is very slow if I keep drawing on every mouse move event?

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Re: Memory expensive rubber band selection?

Eddy Vluggen1-Jun-11 1:00

Eddy Vluggen

1-Jun-11 1:00

Mouse-move events are fired continuesly, and the drawing routine looks expensive. You might want to check whether the mouse has moved in the meantime, not redrawing if there's no movement detected.

Bastard Programmer from Hell Suspicious | :suss:

Re: Memory expensive rubber band selection?

BobJanova1-Jun-11 1:24

BobJanova

1-Jun-11 1:24

I recommend overlaying the semitransparent mask over the base image (either in OnPaint on the picture box or by placing another object over the top). Then all you have to redraw is the mask.

Creating graphics objects is slow, which is why you should typically do it in OnPaint. In fact, in this case, you should do that, and your mouse move handler should only call Invalidate.

Re: Memory expensive rubber band selection?

Pete O'Hanlon1-Jun-11 1:41

Pete O'Hanlon

1-Jun-11 1:41

One other thing to bear in mind. The managed version of GDI+ is slow in comparison to the unmanaged version. You pay a price for the simplicity, and that price is speed.

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Re: Memory expensive rubber band selection?

Luc Pattyn1-Jun-11 1:41

Luc Pattyn

1-Jun-11 1:41

Chesnokov Yuriy wrote:
Why the picture box update is very slow if I keep drawing on every mouse move event?

Because the MouseMove events fire at high frequency (allowing you to track well assuming your handler is fast), possibly 50Hz or higher (which is too high for the human eye to notice), because Graphics objects are expensive, and finally because PictureBoxes are stupid (I wouldn't be surprised if the fact you change the image just causes another mouse move event).

You want to run such things continuously? I would experiment with keeping the two Graphics and the Bitmap around as class members, i.e. not create new objects at all, just keep using them over and over.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Re: Memory expensive rubber band selection?

Chesnokov Yuriy1-Jun-11 1:56

Chesnokov Yuriy

1-Jun-11 1:56

I need to implement rubber band like ROI selection in the image as in paint editor

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