C# Discussion Boards - CodeProject

musefan20-Mar-09 4:51

musefan

20-Mar-09 4:51

well then you dont want to be working with an array of image pixels cuz they will always be valid values

Whats you error?

Life goes very fast. Tomorrow, today is already yesterday.

Luc Pattyn20-Mar-09 4:18

Luc Pattyn

20-Mar-09 4:18

Hi Collin,

Not every stream/file constitutes a valid image; what Image.FromStream() accepts is the streamed content of an image file, as Image.FromFile() would expect. There is more to an image than just a bunch of RGB values; it needs dimensions, pixel depth information, maybe a color lookup table, compression information, etc.

Now what is it you want to achieve? You already have a valid image to start with, so why not modify it rather than copying/modifying its pixels, then work from there.

FYI: setting every third byte to 255 produces red only if (1) you do have a 24bpp image (which would be exceptional, most .NET images are 32bpp) and (2) the image is sufficiently dark (a white pixel will remain white, a yellow one will remain yellow)

BTW: in general when getting an exception, you should look at it; when posting a message, you should report it, that could help getting more and better replies sooner. In this particular case, you were bound to get an ArgumentException telling you not much except the one argument wasn't good enough...

Smile | :)

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20-Mar-09 4:46

N_tro_P

20-Mar-09 4:46

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Luc Pattyn20-Mar-09 5:00

Luc Pattyn

20-Mar-09 5:00

Hi Collin,

if you want to convert an existing image into a stream, use an Image.Save overload that deals with streams i.e. Image.Save(Stream, ImageFormat).

the code you have shown does NOT deal with an image, it only handles pixel data; I suggest you don't try and convert pixel data back into a valid image, just use the existing .NET classes (Image, Bitmap), they know about several image formats.

FWIW: if you are having trouble turning an image into a stream (say a MemoryStream), then reading it back from that stream, chances are you forgot to "rewind" the stream between writing and reading, i.e. to reposition it at its beginning.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fayu20-Mar-09 4:45

Fayu

20-Mar-09 4:45

You can use the System.IO.MemoryStream object to do this.

byte[] buffer;
MemoryStream ms=new MemoryStream(buffer);

Hope this helps.

Message Removed

20-Mar-09 4:49

N_tro_P

20-Mar-09 4:49

Message Removed

Fayu20-Mar-09 4:53

Fayu

20-Mar-09 4:53

Post the exception type and exception message.

Rich text to canvas

damichab20-Mar-09 3:29

damichab

20-Mar-09 3:29

Hi,

I am trying to get some rich text (from a RichTextBox.Rtf) onto a bitmap but can't seem to find a way to do it.

The key lines of my code are...

Bitmap      Canvas = new Bitmap(200, 200, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
Graphics    Artist = Graphics.FromImage(Canvas);

Artist.PageUnit = GraphicsUnit.Pixel;
Artist.DrawString("Hello", descFont, descBrush, rect, descFormat);

It would have been nice if there were a:

Graphics.DrawRTF(string richText, Rectangle rect)

method, but there isn't.

What is usually done as a replacement? Any help or pointers appreciated.

Regards,

David Bailey.

musefan20-Mar-09 3:54

musefan

20-Mar-09 3:54

Whats wrong with the 4 lines of code you already posted?

Life goes very fast. Tomorrow, today is already yesterday.

damichab20-Mar-09 4:04

damichab

20-Mar-09 4:04

Hi musefan,

I am trying to display RichText not plain text. Or are you saying that the DrawString() command handles rich text as well?

-David.

musefan20-Mar-09 4:08

musefan

20-Mar-09 4:08

No, DrawString() will not auto handle your formatting.

Have a look at this[^] for some ideas.

You could always handle yourself by iterating through each word in the richtextbox then getting its formatting(color, font etc.) before drawing it to the graphics object.

Life goes very fast. Tomorrow, today is already yesterday.

Launch Program and embed it or place it on a child form

damichab20-Mar-09 4:22

damichab

20-Mar-09 4:22

Thanks.

I did not think to loop though the rich text. Might just do that.

The link was useful too.

-David.

Wallbert Elicot20-Mar-09 1:46

Wallbert Elicot

20-Mar-09 1:46

Hi.. Am new to C# and our director gave a project.

Basically, what i want to do is launch an external program and place it within my c# app so when i maximize it, it just maximize within my app. I know how to launch an external program. What i want to know is it is possible to place the launched program in a child form for example.

Any help would be appreciated. Thanks..

Re: Launch Program and embed it or place it on a child form

DaveyM6920-Mar-09 2:01

DaveyM69

20-Mar-09 2:01

There's an article on here called Windows Tabifier[^] that does what you want.

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

open existing excel file as a new document. [modified]

amit_8320-Mar-09 1:45

amit_83

20-Mar-09 1:45

Hi,
how can i open an existing excel file as a new document.
and if user close it from upper left close(X) button of doc,
then it should ask to save the document as a new excel doc file.

amit

modified on Friday, March 20, 2009 7:57 AM

Property is IEnumerable

Adriaan Davel20-Mar-09 1:35

Adriaan Davel

20-Mar-09 1:35

Hi,
I need to loop over a class' properties(object.GetType().GetProperties()), and if the property implements IEnumerable I need to respond to that, but I cannot find a way to confirm this, any ideas?

____________________________________________________________
Be brave little warrior, be VERY brave

moon_stick20-Mar-09 2:29

moon_stick

20-Mar-09 2:29

You'll need to have a check that gets the type of the properties and then checks which interfaces it implements. Something like:

<br />
Type[] ifaces = field.GetType().GetInterfaces()<br />
if (ifaces.Contains(typeof(IEnumerable))<br />
{<br />
//do something<br />
}<br />

where field is the property you're looking at.

This might be better implemented as a recursive function if you have a deep object tree.

It definitely isn't definatley

Adriaan Davel20-Mar-09 3:50

Adriaan Davel

20-Mar-09 3:50

Great, thanks. Took me a while to figure out what the results were but makes sense.

Now for the next challenge: For Generics collections you can do object.GetType().GetProperties()[0].PropertyType.GetGenericArguments()[0].Name for example to find out what object is contained by the enumerable, what would the equivalent be for an array?

____________________________________________________________
Be brave little warrior, be VERY brave

moon_stick20-Mar-09 4:13

moon_stick

20-Mar-09 4:13

If I've understood correctly, you need to look at the ElementType of the object:

<br />
int[] myarray = new int[10];<br />
Type arrayType = myarray.GetType().GetElementType();<br />

will return System.Int32

It definitely isn't definatley