Say I have a 5 GB file. I want to split it in the following way.
First 100 MB is on the file
The rest go some reserve file
I do not want to use readalllines kind of function because it's too slow for large files.
I do not want to read the whole file to the memory. I want the program to handle only a medium chunk of data at a time.
In this readalllines part because my data is saved differently now it used to be like this
CODE:
But now i saved it in a single and more understandable line like this
CODE:
And i have afew ideas like using the split function and stuff to read the months but can i use the "|" and "," in the line at the same time? the first 3 section of the line is for user to know the year, month and day of the starting date of the chinese lunar year. and the following 1,30 is the first month with 30days.
CODE:
read each chunk of 256 bytes from a 32k file and then add the total value of each byte's decimal value. This will be some huge number which then needs to be converted to hex (Hex(number)and then truncate down to the LSB (I.E. 7F{4B}) and then convert the truncated byte (4B) back to a decimal (Num = Val("&H" & Num).
View 2 RepliesI am using "For Each S As String In IO.File.ReadAllLines(filetoUse)" to read a file. how acn use EOF with IO.File?
View 2 RepliesIm trying to use File.ReadAllLines to read a DLL that has plain text. (the DLL is basically a text file)
Dim NewFile As New StreamWriter(Application.StartupPath & "NewFile.DLL")
File.ReadAllLines(Application.StartupPath & "NewFile.DLL")
I get 1 error, and I have a few questions
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I'm using IO.File.ReadAllLines(FileName) to read all lines from text file to array of strings at once. Problem is, text lines include ANSI characters above ASCII value 127 (Scandinavian letters e.g. " (Ascii 196), (Ascii 246) and (Ascii 233). Array is build up nicely, but all chars above ascii value 127 are not shown right. How can I use ANSI character set with .ReadAllLines to correct this problem? In VB6 with "Open Filename For Input As #1 / Line Input #1, txtLine" there wasn't any problem. OBS: This is already solved, found the answer by myself:
Dim myEncoding As Encoding = System.Text.Encoding.GetEncoding(1252) ' Windows-1252
Dim strLibrary As String() = IO.File.ReadAllLines(FileName, myEncoding)
Problem was to find right character set, which was Windows-1251 (ISO-8859-1)
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I want to use the GetFileInformationByHandle function under kernel32.dll in order to get the NTFS unique file identifier.The function declaration is like this [code]...
how do I get the file handle (hFile As IntPtr) for a given filename in visual basic ?
Returns whole lines, the odd occasion a word. any thing obvious wrong?
Private _word As String()
Private _i As New Random
Private Sub btnGetNewhangManWord_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _
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Im trying to use File.ReadAllLines to read a DLL that has plain text. (the DLL is basically a text file) [code] The process cannot access the file '****DebugNewFile.DLL' because it is being used by another process.How do I use readalllines to find text? How do I use readalllines to only search a part of the text file?
View 4 RepliesI'm using IO.File.ReadAllLines(FileName) to read all lines from text file to array of strings at once. Problem is, text lines include ANSI characters above ASCII value 127 (Scandinavian letters e.g. "Ä" (Ascii 196), "ö" (Ascii 246) and "é" (Ascii 233). Array is build up nicely, but all chars above ascii value 127 are not shown right. How can I use ANSI character set with .ReadAllLines to correct this problem? In VB6 with "Open Filename For Input As #1 / Line Input #1, txtLine" there wasn't any problem.
View 1 RepliesI have a text file (CSV) approx 100k lines (8Mb). I want to search the entire file for a particular string eg, "apple" and for all lines containing the string to be printed in a text box. have successfully done this using streamReader to parse the CSV and check each element against the search word eg. apple. This has proven to be very very slow and I have read that the "ReadAllLines" method is much faster.
View 8 RepliesI need to read and process a text file. My processing would be easier if I could use the File.ReadAllLines method but I'm not sure what is the maximum size of the file that could be read with this method without reading by chunks. I understand that the file size depends on the computer memory. But are still there any recommendations for an average machine?
View 3 Repliesdoes visual basic have any function to allocate a memory by specfying the size of it? I just want to experiment with it, like see what happens when i allocate 2GB of memory on my p3 MHz 512MB ram box =) I know obviously it will crash or have high page file access.
View 8 RepliesThought I'd see if Stack overflow is quicker than me testing something while I get a thousand interruptions from other work :)
I'm updating an old VB net application and trying to refactor some of the logic as I go. The app looks for data from a single date across a few tables and writes that view to a file.
Writing the query in SQL I'd get the equivalent of
SELECT * FROM table
WHERE CAST(FLOOR(CAST(table.date AS float))AS datetime) = '15-Jul-2010'
Ideally I'd use
SELECT * FROM table WHERE date=@input
and add a date object as a parameter to a System.Data.SqlClient.SqlCommand instance
Are those two comparable? Will I get the results I expect?
Is there any way we could get directly say the 1000 characters after the first 5000 characters, skipping everything before that after sending in an HTTP request to an HTTPS page using either GET or POST in VB.NET? The reason why I ask this question is because in one of the webpage I am trying the get through my program, the website is sending response data in chunks with the first chunk containing some javascript garbage that I have no interest in, the only data I care is in the second chunk and
how to get the second chunk after receiving the first one since it is within the same HTTP request.It would save some time and Internet traffic if I can skip the first chunk that I do not need.Is that possible or I am just day dreaming?
ADDED: Here is how a typical header of the response I am getting from the webpage I am trying to get:
Date: Mon, 20 Jun 2011 13:21:56 GMT
Set-Cookie: JSESSIONID=1AF1AF9EF936E1CB2FA85B750EDC67C4; Path=****some path******; Secure
Content-Type: text/html; charset=ISO-8859-1[code].....
Not sure if that helps, but as you can see, the chunk size is not visible to me, there is no "Trailer" in the header as well.
I am in the main process using Activex EXE to create a sub-process, Activex EXE project inside a class module, class module which there are two instances of the event the equivalent of two threads, I defined the standard module module1.bas as public variable a, in two instances running at the same time, how the definition of public variables are not used, such as a private variable, each carrying out their respective variables of the same name! For example the implementation of a = a +1 statement, let the first instance of a run, a steady increase from 1; when executed when an instance of 2, a should be an instance of a value when the two began to increase, but also from two examples of 1,2 , ... began to increase.
[Code]...
When i run the program everything works fine. I want the textboxes to keep the data in them till the next time i run it. Right now when i shut it down (with data in the textboxes) then start it up i have lost all the data.
Heres my code
Private Sub TextBox2_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox2.KeyPress
'Numeric values only
If Not Char.IsNumber(e.KeyChar) And Not e.KeyChar = Chr(Keys.Delete) And Not e.KeyChar = Chr
[code]...
We have a vb.net desktop application that uses a number of graphical images. All is well when the Windows Display is set to the default small font; however, when the display is set to the medium (125%) font, the graphical images don't display properly. We can accommodate the changes to windows sizes and text boxes, etc using autoscale and autosize; however, this doesn't help with images. Is there any way to overcome this issue?
View 2 RepliesIn an ideal world, we wouldn't need to educate our users about the "intricacies" of ZIP files One of my apps is a stand-alone-ish app that has no dependencies that need to be installed. Well, except for the Framework of course.So, in order to make the download smaller, I've zipped up the package. One of the functions of the app is to download some files into a subdirectory the application is located within. Well, some users don't unzip the package and as we all know, you can't just download some files into a ZIP file. I spent a good 20 minutes looking through my code and adjusting things to figure out why it wasn't working for one user, when I realized there were no issues in my code and that he probably wasn't unzipping the package.So, does anyone know of a method to determine if the directory my app is in, can be written to?I know I can just try writing a small file or something and catch the exception, but that seems... sloppy.
View 7 RepliesI want to work on a project I have in mind and this envolves saving data which would need to be updated every time the user exits the program. I suppose I need to know how to save a file to a blank text document, and how to get the application to read the information when it is called for. I believe I need to set delimiters or such, the helpfile is useful, but limited and some information is not listed at all.
View 7 RepliesMy program turns on and off external relays from the parallel port. I need to find a way to activate the relay only while a wav file is playing and de-activate the relay when the wav file stops playing.
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Why can't a sub implement an interface and handle event at the same time? The following gives my a syntax error:[code]I know I could handle this kind of logic with another method, but that is not the point. I just want to understand the reasoning behind this.
View 2 RepliesIs it possible to read the GUID from the Assembly without actually loading it in the current App Domain.
Normally Assembly.Load loads the DLL into the app domain. I just want to read the value. The description of the GUID is
'The following GUID is for the ID of the typelib
' if this project is exposed to COM
<Assembly: Guid("DEDDE61CD-928E-4ACD-8C25-3B8577284819")>
The main thing is I don't want to lock the file so that there are no errors 'Another process is accessing the file' error.
Is there an event that I can handle that is fired when the computers system time is changed?
My program timestamps things, and I want to make sure the time is correct. So when the program starts, I will run a query (SELECT GETDATE()) from my SQL server, and record the difference, in seconds, between the SQL server time, and the time returned from NOW(). Then when I timestamp things, I will just adjust the time. I cannot run a query every time. But, if someone changes the clock on the computer, that would throw the timestamp off. So I need a way to know when this has happened, so I can recalculate the difference.
I have a form for which the form load event only fires one time. When the program starts. It will not fire again until I end the program and restart. I have tried .show and .showdialog, but it acts the same. I have read about form load events loosing the handles, but my code looks exactly like it should.
Here is the load event code
PrivateSub frmBilling_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesMyBase.Load
LoadClients()
LoadTherapists()
LoadCPT() EndSub
Here is the code that calles the form.
PrivateSub BillingToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BillingToolStripMenuItem.ClickfrmBilling.Show()
frmbilling.show()
EndSub
My motive to prepre a application which can calculate free time of the team which handle. I have written a code which updates the username and current time in an access database. How can i run the code on windows lock event.
View 7 RepliesI have a UserControl with a Panel (Panel1). The UserControl has a property Items (type ControlCollection) that returns the Controls collection of Panel1.Via a custom CollectionEditor, I tell the designer that it should add my custom controls called Item (inheriting Control). For the sake of example, the Item control is just a control with a random background color:[code]The custom CollectionEditor creates new Item controls using the DesignerHost service (and its CreateComponent method), so that they appear as actual components in Panel1, selectable during design-time just like any other control.It might be a little hard to see (because the colored Items are docked to the top), but I have selected the red item, which can also be seen from the Properties list.
As you can see in the code, I attach a Click event handler to each item as it is added to Panel1. When clicked, a MessageBox shows the color of the item. Obviously this is just for the sake of this example, but the point is that I need to be able to click an item and something then needs to happen.This works fine during run-time. I can click each item, and the MessageBox shows.The problem is that it does not work (quite obviously) during design-time. When I click it during design-time, it is simply selected (as any other control) and of course does not register any Click (nor MouseClick) events.But, I need the Click event to fire even when in design-time! Clicking an item corresponds to selecting it, and when selected (even in design-time), some other panel (not shown in this example) should be brought to the front so it gets visible. Now, I have created lots of things very similar to this (clicking an item during design-time), but there has always been one major difference: those items were not actual controls on the form. Instead, they were drawn manually on to their parent (and they only looked like separate controls). Obviously there was no design-time support for those 'items' (as they weren't controls), but I could handle clicking them quite easily: by handling the MouseClick event of the parent, I can check the location and see if it falls within an item. If so, that item was 'clicked' (artificially).This time, the items are actual controls, and this method does not work (the parent does not receive a MouseClick event either).So, does anyone know of any way to do this? The only way I can think of right now (although I have no idea how to implement it) is to somehow 'listen' to changes in the designer selection.
I am pulling three coloums of data from a SQL view into my data drid Day,TimeIn,TimeoutI want to colour my datagrid rows red if timeout is null and green if both the timein, timeout have data in them.[code]
View 2 RepliesIs there a way to use ReadAllLines to read in a text file that contains some Chr(10) (linefeeds) but uses ONLY the Chr(13) (carriage return) as the true end-of-line?What I mean is, DON'T treat a Chr(10) as the EOL. ONLY treat a Chr(13) as the EOL.Obviously I could just read in the whole file as binary and then split it into lines by scanning for Chr(13), but I just wondered whether or not there's a setting in VB.NET to set the EOL character so I didn't have to do that.
View 4 RepliesSo I have a relatively small website with growing amounts of data - the fastest growing table is pageviews, as we do all our analytics ourselves. The website is made using VB.Net, SQL Server 2008 and jQuery. I am limited to .net 2.5.I currently handle all the data and validation using objects with a list of attributes. Each attribute is of a specific datatype and has a validation function when a new value is given to it. If the data does not validate then it won't even get as far as updating the database and feeds back an error to the user. Currently I have "Manager" classes and "Item" classes - Items are managed by a particular Manager class, for example Users are managed by the UserManager, so to get all the users I just have to call UserManager.Items. These Manager classes are stored in the cache and are created as needed - but once a Manager class is referenced it creates all of the Items within it. This is getting rather slow now, as the company is growing fast. It takes 2 - 3 seconds to load the first page (the page which makes most first-time requests to data) but I am not happy with this time. After that it is nearly instant.
Now the way I see it I have 3 options to speed the website up: Keep it as it is, but try to make it more efficient through other techniques;Change to creating all these objects on every page load, in the hope that it is simply so slow because I am using the cache to store a fair amount of data (about 10 MB or so at least);Forgetting using object oriented techniques and just use straight SQL queries and loop through records.