.NET (Core and Framework)

15-May-04 12:23

Ok, in no way am I a N00b at reading files! However, I was debugging some code today in which I was using a IO.StreamReader to read the text from a file and using an IO.StreamWriter to write it into a different file.

This file is about 3.2MB. The StreamReader DOES return the Correct Length of the File (IO.StreamReader.BaseStream.Length). HOWEVER, while reading the file, the Stream THINKS it has reached the end, and like a good little programmer, I Flush the StreamWriter (BTW, I am flushing every 8096 Bytes - yes, that IS a lot of water!) but I am missing a HUGE chunk of data at the End of my file!

I have noticed that the IO.StreamReader.BaseStream.Position is usually TOTALLY different than the Sum of the Bytes returned for each re-iteration of retrieving data. For example, reading in 8096 Bytes at a time, when my Position variable thinks it's at 16,192, the BaseStream has it's internal buffer set to some other amount... Is this what's messing it up?

Notice however, it I REALLY want to waste a lot of memory and processing time, I can just read it all in at once (IO.StreamReader.ReadToEnd) and then process it....GreeeEEEAAAaaaat!!! Just what I want! NOT!!!

So...what the @%$* is going on!??? How do I read the rest of the data!??? WTF | :WTF:

mikasa15-May-04 12:40

15-May-04 12:40

Wait a tick, it gets even better! I just discovered that it's Reading past the end of the File and returning more data than it should!

So, I know I need to use this handy-dandy Routine MS gave us: IO.StreamReader.DiscardBufferedData(). Soo, anyone have a clue as to how this should be done?? Any examples? Becuase the Help doesn't...well, help! Confused | :confused:

mikasa15-May-04 12:59

15-May-04 12:59

Ok, I found the answer to this. I'm sure most of you do not need this functionality and only use "ReadLine"... However, try parsing ANSI 835 files Poke tongue | ;-P

. (Yes, I'm aware there are 3rd party Libraries for this, but I hate them)

- The End Poke tongue | ;-P

TigerNinja_20-May-04 8:34

Denn Gott hat die Menschen so sehr geliebt, daß er seinen einzigen Sohn für sie hergab. Jeder, der an ihn glaubt, wird nicht verlorengehen, sondern das ewige Leben haben

20-May-04 8:34

mikasa wrote:
Ok, I found the answer

So can you kindly share your solution with the CPians ?

Thanks.

R.Bischoff

mikasa20-May-04 8:46

20-May-04 8:46

Sure thing, just curious if anyone would reply Poke tongue | ;-P

'Function to Read a File into Cache so RegEx can be Performed
Private Sub CacheFile(ByVal File As String)
	Dim ioReader As IO.StreamReader
	Dim vBuffer() As Char
	Dim hResult As Integer

	'Exit if the File does not exist
	If (File = "") Then Return
	If (Not IO.File.Exists(File)) Then Return
	If (Me._File <> File) Then Me._File = File Else Return

	Try
		'Initialize the Cache
		_Cache = Nothing : _Cache = New System.Text.StringBuilder(8096)

		'Read the File
		ReDim vBuffer(8096)
		ioReader = New IO.StreamReader(File, System.Text.Encoding.UTF8, True, 8096)
		hResult = ioReader.Read(vBuffer, 0, vBuffer.Length) 'Read More Data
		While (hResult > 0)
		     'There is a bug with a StreamReader.  Sometimes more data is read than is neccessary.
		     'If these are the Last Bytes of data, only read up to the hResult
		     If (hResult < vBuffer.Length) Then _Cache.Append(vBuffer, 0, hResult) Else _Cache.Append(vBuffer, 0, vBuffer.Length)

		     hResult = ioReader.Read(vBuffer, 0, vBuffer.Length) 'Read More Data
		End While

	Catch ex As Exception : MsgBox(ex.ToString)
	Finally
		Erase vBuffer
		If (Not IsNothing(ioReader)) Then ioReader.Close() : ioReader = Nothing
	End Try
End Sub

Colin Angus Mackay23-May-04 2:00

Colin Angus Mackay

23-May-04 2:00

In your code you have:

_Cache = Nothing : _Cache = New System.Text.StringBuilder(8096)

Isn't the first statement somewhat redundant?

"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

The Second EuroCPian Event will be in Brussels on the 4th of September

Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way!

mikasa23-May-04 6:51

TreeView - Howto add Controls?

23-May-04 6:51

I don't trust VB nor the Garbage Collector Poke tongue | ;-P

mgaerber14-May-04 9:23

mgaerber

14-May-04 9:23

Hi,

most of us have read articles about list views
with controls like Textbox etc. added for editing functionality. This is nice but not sufficient if you want to cleanly display hierachical data.

Any suggestions on how to implement something similar with the TreeView?

For example a subnode would not be simple TreeNode but something like a Panel or similar on which one could put a TextBox for data input?

Re: TreeView - Howto add Controls?

mikasa15-May-04 13:00

Re: TreeView - Howto add Controls?

15-May-04 13:00

Infragistics Controls can do this...

TigerNinja_18-May-04 19:14

Denn Gott hat die Menschen so sehr geliebt, daß er seinen einzigen Sohn für sie hergab. Jeder, der an ihn glaubt, wird nicht verlorengehen, sondern das ewige Leben haben

18-May-04 19:14

I believe it is built into the .NET Framework, please review this documentation
http://msdn.microsoft.com/library/en-us/cpref/html/frlrfSystemWindowsFormsTreeViewClassLabelEditTopic.asp[^]

R.Bischoff

composite web control

sangeetha bhatta13-May-04 19:10

sangeetha bhatta

13-May-04 19:10

Hi,
I wish to develop a WEB control in .NET ( or know of any such existing control) which works similar to the SQL Server table's data entry sheet.
to be more elaborate:

i will be specifying number of colums for that control.
2 rows with those many columns appears.
i fill in the data. and when i start filling the 2nd row
a 3rd empty row should appear.

Re: composite web control

TigerNinja_14-May-04 8:01

14-May-04 8:01

Hello,
What exactly is your quesiton? Please be more specific to the problem you are having.

Thanks.

R.Bischoff .NET, Kommst du mit?

Great Freeware -> Abilon - Rss Reader | Zip Genius | SmartFTP

.net

Yulianto.13-May-04 17:44

Yulianto.

13-May-04 17:44

i want to install visual studio .net, but i have a problem, i can`t install ie service pack, i don`t have connection to the internet. is it really true that u need to connect to internet. i`m running the update, copying from a friend. thanks

Re: .net

TigerNinja_14-May-04 8:05

14-May-04 8:05

System requirements for VS.NET, full page here: http://msdn.microsoft.com/vstudio/productinfo/sysreqs/default.aspx[^]
Visual Studio .NET 2003 can be installed onto any of the following systems:
Microsoft Windows® Server 2003
Windows XP Professional
Windows XP Home Edition¹
Windows XP Media Center Edition
Windows XP Tablet PC Edition
Windows 2000 Professional (SP3 or later required for installation)
Windows 2000 Server (SP3 or later required for installation)

The install can update some packages from the Internet, but it is not required.

R.Bischoff .NET, Kommst du mit?

Great Freeware -> Abilon - Rss Reader | Zip Genius | SmartFTP

TELL ME I'M WRONG !!

philippe dykmans13-May-04 15:13

philippe dykmans

13-May-04 15:13

Hello guys,

Say, i need a little cheering up here...

I've been programming in .NET for over two and a half months now. And at this point i've come to the conclusion that i doubt .NET more than i doubt myself. IMHO a pretty dangerous situation. Back in mfc-days i used to spend two days on a problem before turning to internet to see if a MFC bug was involved. Now, in .NET, i turn to internet to see what bugs i can expect before i even put as little as a textbox on a form. Is this normal??

I absolutely adore C#. No doubt. And I must admit that .NET can be an incredibly powerful platform. Moreover, i'm convinced that it once WILL be. So, i will try to hang on to it as long as possible. But then again... boy... am i glad i skipped version 1.0!

Please tell me i'm wrong!

Ok, a few examples:

- A textbox without a border cuts off the lower parts of characters like y, p and g. Mainly in fontsize 11 with AutoSize turned ON.

- Listviews don't display item images when put on a usercontrol in a usercontrol. And the headers have serious painting errors.

- Listboxes don't always fire their click events.

- Tabpages cannot be disabled or hidden.

- When i move a project to another location, i always do a complete rebuild. Of the project itself and of any other projects involved. Compiles with no errors. Two weeks later, for no apparent reason, the program crashes on the exception that there are no appropriate resources compiled into the control. Rebuild all... no errors! Run it... and crash!!

- Every now and then controls dissapear from the designer. Takes a few rebuilds and IDE restarts to get them back on... most of the time... yet not always.

- I need a virtual listview... nope. The solution? Unwrap the .NET control piece by piece until it is stripped to the bare Win32 control and use the API and messages like we used to. Only... this time lookup the old header files to get all the constants, change "defines" into "const int", don't forget the WndProc and spend another hour packing all the structs into the right marshalling format. ALL my controls have at least two platform invokes!! And this is the only solution that is proposed over and over again. Everywhere you look for answers, they always boil down to "strip the .NET part and start programming like you used to...". But is that a future-stable solution?

- Some scrollbars are XP, while others stay Win95. Or was that Win3.11? And scrollbars tend to lie if you ask them if they are visible or not.

- A simple picturebox has no scrollbars!!

- When i start my old MFC software, ALL the controls and dialogs obey to the XP themes and colours. But not my .NET application!!?? I know, i know...
Application.EnableVisualStyles();
I DO that! Nevertheless, textbox backgrounds fail, and some dialogs too! While the least i had expected was to have visual consistency!

And these are only a few among many.

.NET is supposed to be the platform that rockets you into writing stable and gui-intensive software. Well... maybe... once it's debugged.

Ok, i'll stop nagging. Just please, tell me i'm wrong!

Thanx for bearing with me Wink | ;-)

Grtz,
Philippe

Sleepy | :zzz:

Philippe Dykmans
Software developpement
University of Antwerp

Re: TELL ME I'M WRONG !!

TigerNinja_14-May-04 13:52