I have a VB 6.0 application that works with random data files... Now I have to create a .Net 4.0 application that generates and update random data files.... Net Framework 4.0 can work with random data files ? Does it support again this old tecnology ?
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how do you save data stored in an array of records (structure) to a text file using StreamWriter? I currently have
Private Sub btnSaveToFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSaveToFile.Click
Dim sw As New StreamWriter(New FileStream("EmployeeDetails.txt", FileMode.Create, FileAccess.Write))
For Each record As EmployeeType In employees
[code]....
but it doesn't work. My array is fixed and currently has 3 elements (for testing purposes). If I enter two records and add these to the structure I get the following data saved to the text file:
123,helen,66000
879,john,89975
0,,0
How do I stop unused elements of the array being included when writing to file? Should I use a dynamic array instead and if yes, how do you use dynamic arrays with structures?
I need to grab just one row, and output its name and details properties to a sidebox on my page.So far I have come up with this, which is not working and giving cast errors between the entity and the list of.
Public Shared Function GetOneRow() As String
Dim db As New Model.Entities
Dim rowCount As Integer = (From t In db.Table Select t).Count
[code]....
I've seen many examples in LINQ but i'm not able to reproduce the same result in vb.net.
I have following code: Dim context As New MyModel.Entities()
Dim rnd As New System.Random()Dim gardens As List(Of Tuin) = (From t In context.Gardens Where _
t.Approved = True And _
Not t.Famous = True _
Order By rnd.Next() _
Select t).ToList()
[Code]...
When I create a new project in VB Express, I get the following 2 errors:
Warning1Value cannot be null.Parameter name: serviceInstance00
Error2.NET Framework 2.0 update not found. The win32manifest will not be embedded.WindowsApplication1
How can I fix this? Windows Vista Home Basic
Consider the following code:
Dim Working As Boolean = False
Private Sub TreeView1_AfterCheck(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterCheck
If Working Then Exit Sub
[Code]...
Where TreeView1 is a TreeView added to the form, with CheckBoxes set to true and one node added. The code basically cancel any node checking occuring on the form. Single-clicking the top node to check it works well : your click is immediately canceled. Yet if you double-click the checkbox, it will display a tick. But verifying the check state through a right click will yield a Checked = False dialog.
How come? Is it a bug (I'm using the latest .Net Framework 4.0, and he same occurs in 2.0), or am I doing something wrong here? Is there a work around?
EDIT: Additionally, the MouseDoubleClick event is not raised before you click once again.
EDIT 2: Posted a bug report at Microsoft Connect
EDIT 3: See this bug report as well.
I'm trying to update a specific record based off of a users selection. Regarding Entity Framework syntax, I'm not very familiar. Is it possible to achieve this SQL statement in Entity FrameWork?
View 3 RepliesI would like to update a row like this:
update [approvers] set approvalstatus = True Where approvalstatus = False and bookingID = @bookingid and approveremail = @email
Using the entity framework.
I have my query which should deliver the item like so:
Dim db As New Model.Entities
Dim approvers = From a In db.approvers Where a.ApprovalStatus = False And a.BookingID = BookingID And a.ApproverEmail = UserName Select a.ApprovalStatus
How do I next target this record for update, so that I can set a.approvalStatus = True then commit these changes to the db?
I'm trying to update one value of a compound primary key from within the entity framework and I'm getting this error: "The property 'CustomerID' is part of the object's key information and cannot be modified. "[code]...
View 4 RepliesI have 2 tables in my DB: "Competitions" and "CompetitionAnswers". Each competition will always have 3 answers. I want to be able to edit the Competition and CompetitionAnswers for the same view. I have managed to get the view to work by using editor templates So this is my editor template:
[Code]...
How to update the existing Customer object, Insert new Computer object and Add new WorkOrder using entity framework? [code]
View 2 RepliesShould I consider packaging with my program the .net framework files?
View 1 RepliesAbout what audio components are exposed by the .net framework?
Can I work with .wav files? What kind of things can I do with .wav files as far as vb .net is concerned? Can I record? What should I look for when looking for info for .net related audio at msdn. Where else can I find info on this?
I have an object (ClassGPS) containing a DataTable that is exposed through the property "Satellites". My form has a bindingsource that, upon load, associates itself to a new ClassGPS object. The table has 5 columns, two of which ("PRN" and "dB") I want to chart using the new 4.0 chart tool. So the chart object's DataSource = ClassGPSBindingSource, and the DataMember = Satellites. That is all set in the designer.In ClassGPS.New(), the table is pre-loaded with 4 rows. This object is created before the form loads. When the form loads and the bindingsource is set to the created GPS object, the chart correctly updates and displays the four pre-loaded entries.On this form, I have a button that adds more entries. Tracing from the Click event, pushing the button does add the entries properly to the underlying table, and if I create a ListCHanged handler on the data source, the events are all correctly firing, but the Chart does not update to reflect the changes.
So to test, I added a Datagridview object. Just like the chart, I set its datasource to ClassGPSBindingSource, and the DataMember to Satellites. And here's where it gets weird. In the designer, the newly added DataGridView control has 4 columns in it labeled RowVersion, Row, IsNew, and IsEdit. I didn't create these columns, it does it itself. If I try to change the bindings on these columns to reflect the actual datatable names (PRN and dB) two things can happen:
1) If I hit Play (F5) to debug the program, the DataGridView looks and acts correctly inside the program and is correctly bound and updating fine as I add new data. In the designer underneath however, the changed columns have disappeared and are replaced with the original four it is creating for no apparent reason. When the debug session terminates, the columns - which just finished functioning fine in the debug session - are now gone.
2) If I hit Build, the designer destroys my columns immediately and recreates those it defaulted to.In either case, something very fishy is going on... in that the Chart, with the exact same binding settings as the datagridview, does not work but the datagridview works just fine (unless Build is hit prior to Run).Has anyone run across this? Can you reproduce it? I have bound a chart to a datatable before and it worked just fine, but it didn't have to update except when the form it was on was closed and later re-loaded.
I am writing the source code to write the random files name but I don't know how to write that in vb.net Here it is the
[Code]...
I am trying to convert a VB5 program to VB2010 so that I can continue to support it on my new PC. My copy of VB5 was an upgrade from VB3 which was an upgrade from VB2 which came on floppies, so I can't just install every preceding version as my new PC doesn't have a floppy drive.I have accepted that I will have to design all the forms from scratch (whatever happened to twips?) and will have to go through the thousands of lines of code line-by-line, but I have hit a brick wall when it comes to random access files. One such file is defined in the Declarations section of Module1 thus:[code]....
I soon found I had to change Type to Structure, but then in the declaration of transrec, transtype acquired a wavy blue underline with the error message: "'transrec' cannot expose type 'transtype' in namespace 'Treasurer_2010' through module 'Module1'.So if I can't use the structure in the module in which it is declared, where can I use it?
how to read and write random access records in .NET. Now I know random access files are dead and the response on every query I found with google/bing/yahoo searches was don't use random access use Binary serialization but I can not. I have a situation where I need to read and modify 256 byte records in a file that is used by another application.
Now for a bit of background the file is made up of 27 fixed length records of 256 bytes. Each of the records has a separate structure consisting of 30-120 fields. The proplem I am having is I can create the record structures but when using the FileGet method I am receiving an error. Now I have found samples that showed the same format I am using that claim to work.
The error I am getting is Option Strict On disallows narrowing from type 'System.ValueType' to type 'ProgramName.ModuleName.Record' in copying the value of 'ByRef' paramater 'Value' back to the matching argument.
The basic layout (simplified) is as follows:
Code:
Structure Record
<VBFixedString(6)> Public SomeParam as String
Public SomeNumber as Short
[Code]....
Now the overloads for FileGet show all of the data types including Object. But I have tried various methods to retreive the 256 byte record but without success. Do I have to actually read each of the several hundred fields of the structure one by one? Or am i overlooking something (I have been known for this in the past)
Or (and I'll kick myself if this is the only way) do I just have to set option strict Off in the module and the code as above will actually work.
I would love to be able to just ditch the random access file but I have to keep it for compatibility with several other applications at this time.
I have 15 years' worth of files (approx. 10,000) that were created using VB6 structures and stored using the random access method. I am trying to write a conversion routine that will read the old structures and put them into a new format that is more compatible with the .net environment. I have not been able to successfully read any of the old files using the tools available in .net. Each file starts with a header record structure. The header record tells me how many tags are in the file. The next record (ie record number 2) is the first tag pointer record in the file.
There are num_of_tags of the pointer records. Each pointer record has the string that holds the tag's 'literal name and two long integers that tell where in the file this tags records are. Those actual records are stored as History data structures, [Code]
I am making a basic form that has 1 button and a rich text box.I need to click on the button and have it call a random line from 3 text documents (so 3 lines total) and place them in the rich text box, each on a different line.
"Quick example"
3 Text files
Firstname.txt
Lastname.txt
Number.txt
Click on button named generate and in the text box below it places
First Name: Shara
Last Name: Harrow
Number: Seven
I'm trying to convert an old Quick BASIC program to VB.Net. There doesn't appear to be any direct replacement for the old file statements. Building a database seems like overkill for my simple needs.
How can I do the following in VB.Net?
OPEN "test.dat" FOR RANDOM AS #1 LEN = 20
FIELD #1, 10 AS a$, 10 AS b$
LSET a$ = "One"
LSET b$ = "Two"
PUT #1, 1
GET #1, 1
PRINT a$, b$
CLOSE #1
i have to write a simple Hangman game with sum extra features for bonus points.... the funny thing is i can write the code for the extra features such as "adding additional word, help menu...etc",but i cant write the main program,The program must select random word from text files, it have three difficulities, the codes should be the same for all three, just read from different files...(well thats what i think)... i think i hav to use array... but how do i read the contain of the text file into an array n randomly select a word?
[code]...
I wanta make a autoupdater with my website but the thing is that the files i upload always have a random link it not like [URL] its like [URL]. so can i still get the autoupdate i saw some tuts with it i got it to read the txt but i was thnk that can i make it read a txt with the link in it then goes to it
Here is what i want it to do
Start Program>Click Update>ReadtxtVerison(website)>ReadLinkLocation(website)>Goes to link in the link.txt>Downloads>Deletes Old Ver>restarts
thats would be awesome if u get it for me and thz
This is wut i got so far
Private Sub Start_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
CheckForUpdates()
End Sub
[CODE]...
I'm working with random access files. I created a module and in it put the
Structure PersonData
Dim Name as String
Dim Age as Integer[code]....
The problem is strange... it will let me input string lengths of 3 for Person.Name and Person.Description and it will save correctly, however, the moment I try and lengthen the string (or even if it's longer than 3 to begin with), I get a 'bad record number' error.
I have recently decided to give .net another chance, but i have a few questions about it before i get really into it. RE: Files, I use random access files to store data as opposed to databases (namely i don't see the need for a database for storing so little information(records <200 max) knowing that it is an older system and less "cool" i don't care...) Will vs2010 express read, write to random access files? Would it be done kind of like vb6 (which is my current vb version)? I will be needing to print the text of rich text boxes, is vs2010 express capable of doing this?
View 7 RepliesWhy is it sometimes when I update a data using da.update(ds), the data sometimes didn't update or change... for example i want to change the name or number n a record, sometimes there is no changes..
[Code]....
I'm having a heck of a time figuring this out, the tutorials I found on the web are not complete or are for VB 6.0 (obsolete in some cases). On the C++ side I have the following ::
hwndExternalApplication = FindWindow(NULL, L"Dromocast Client");
SendMessage(hwndExternalApplication, WM_SETTEXT, NULL, (LPARAM)"Hello");
"Dromocast Client" is my visual basic application, and I checked to make sure it's not NULL. In fact I get made sure I'm getting some data on the VB side. On my Visual Basic side I have the following
[Code]...
When I send the data over it's garbage, meaning strTemp comes out as all these chinese characters, and my title bar on the visual basic program gets garbled with a bunch of chinese characters as well. My guess is my "SendMessage" is written wrong, or I'm doing something silly, but I have no idea what. I'm not a windows programmer so I'm kinda trying to figure this stuff out by googling.
I am used to using datasets for my projects in terms of data access. I now set myself an easy app to work on in order to learn the entity data framework and how to retrieve & manipulate data.Can anyone guide me through on where to start, what are the advantages of this model, In what scenarios should I choose to use entity framework and what are the things (basis) I should now before starting.My datasets are working fine too. Are there any reasons for me not to stick with that way of accessing data? Or is this something to consider depending on the users of the website (for speed purposes etc.)
View 3 RepliesI want to update an entity without loading the entity from the database first. I've accomplished this but only by knowing all of the entities properties and then using the "attachto" method. My issues is i don't want my app to need to remember all of the properties. Example:
[Code]....
I'm using EF version 4.1, and would like to have the data from the database in realtime, i.e. if you open the application it detects if there is new data in the database, and update the above it! is It possible to do this? I am using EF 4.1 code first time
View 1 RepliesI am having trouble getting the new Entity Framework's objects and classes to store data in my database. I have tried basically everything I can think of, asked for various forums with no success, and I am starting to wonder if the new EF is merely for reading data and not saving it. Now, I decided to make atest Console application to make a single record in the database. The code is quite simple:
Sub
Main()
Dim ent As New MyModelEntities()
[code].....
