Graph implementation - Visual Basic Discussion Boards

Johan Hakkesteegt2-Jan-07 22:39

2-Jan-07 22:39

Hi Somasundaram,

We have several VB6 and VB.NET applications that use MSAccess. We found that the easiest way is not to try and write data straight to the MSAccess database (= tricky), but rather to an actual database (= easy with VB.NET), and then linking to the table(s) from MSAccess (= easy). If you have no Database program other than MSAccess, there is always Microsoft's free SQL Server 2000 Desktop Engine (MSDE).

Johan

My advice is free, and you may get what you paid for.

Read Only Files

jady842-Jan-07 12:18

jady84

2-Jan-07 12:18

Hi,

I have this strange problem, Im using VB Express 2005 and im programming on my desktop computer, however when i shift the file onto my laptop the file comes up as "read only", meaning i cannot edit it in anyway.
Now if i right click the file and uncheck the read only box, followed my clicking apply, and ok.
I then go to work but still cannot edit the program and when i go to right click the folder again the read only box is checked.

Hope someone can help me with this very jarring problem.
Thanks in advance.

Jaidev

Re: Read Only Files

MatrixCoder2-Jan-07 12:46

MatrixCoder

2-Jan-07 12:46

I've had similar problems before. You could try Unlocker.

Trinity: Neo... nobody has ever done this before.
Neo: That's why it's going to work.

Re: Read Only Files

jady843-Jan-07 10:27

jady84

3-Jan-07 10:27

Hi,

Unlocker doesnt work. any other ways?

Cheers

Jaidev

Re: Read Only Files

MatrixCoder3-Jan-07 14:38

MatrixCoder

3-Jan-07 14:38

It didn't work for me either, I was hoping it would work for you. I still haven't fixed some of my files. I have some files that I can't copy from one hard drive to another after reinstalling Windows. They got corrupted and they're locked too, there's something holding control of them but I can't find it.

Trinity: Neo... nobody has ever done this before.
Neo: That's why it's going to work.

Re: Read Only Files

Colin Angus Mackay2-Jan-07 12:46

Colin Angus Mackay

2-Jan-07 12:46

How are you transferring your files between the desktop and laptop? If you are burning them to a CD or DVD then they will become readonly by the nature of the medium by which the data is transferred. In otherwords, there isn't anything you can do about it. Each time you copy you just have to remember to clear the readonly check box on the files each time you copy them. You can do this on the parent folder and have it apply recursively to all files in the folder.

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Re: Read Only Files

jady843-Jan-07 10:26

jady84

3-Jan-07 10:26

Im transferring my files via my usb memory stick. I turned the read only check box off before transferring the file again but no luck.
Any other possibilities? (also tried the unlock software, but no luck again).

Cheers

Jaidev

Graph implementation

maisa.sh2-Jan-07 11:52

maisa.sh

2-Jan-07 11:52

i have a graduation project and i need the graph imlementation(nodes , edges)??

Re: Graph implementation

Christian Graus2-Jan-07 13:22

Christian Graus

2-Jan-07 13:22

Please don't ask over and over. There are commercial libraries that draw graphs. If a graph is integral to your graduation project, then I'd expect you should be writing your own code to draw graphs.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

DataGridView DataSource changing !!

kindman_nb2-Jan-07 11:06

kindman_nb

2-Jan-07 11:06

Hi
I'm using vb.net 2005 , and when change the DataSource Property of DataGridView , I found that all the Columens properties like HeaderText and Width are changed to default values ,

How can I prevent that ..

Thanks for all Rose | [Rose]

jooooo

Re: DataGridView DataSource changing !!

kindman_nb2-Jan-07 11:12

kindman_nb

2-Jan-07 11:12

I mean changing DataSource Property on Run Time

jooooo

Re: DataGridView DataSource changing !!

darkturtle2-Jan-07 22:05

darkturtle

2-Jan-07 22:05

This is probably the long way around but you can load a column style before you name the data source. I cannot see why you are losing the data but this will over-write anything else. See code below I copied direct from one of my old projects- where workTable is the table in my dataSet and I just iterate through the workTable column names to add then to the datagrid

Private Sub LoadCvCalcTableFormat()

' Create a new DataGridTableStyle and set MappingName.
Dim tableFormat As DataGridTableStyle = New DataGridTableStyle
tableFormat.ColumnHeadersVisible = True
tableFormat.PreferredColumnWidth = 75
tableFormat.PreferredRowHeight = 30
tableFormat.RowHeadersVisible = True
tableFormat.MappingName = workTable.TableName

' Iterate through table columns and format each one.
Dim i As Integer
For i = 1 To workTable.Columns.Count - 1
Dim colStyle1 As DataGridColumnStyle = New DataGridTextBoxColumn
colStyle1.Alignment = HorizontalAlignment.Center
colStyle1.Width = 75
colStyle1.HeaderText = workTable.Columns(i).ColumnName
colStyle1.MappingName = workTable.Columns(i).ColumnName
tableFormat.GridColumnStyles.Add(colStyle1)
Next

' Add the grid style to the GridStylesCollection.
DataGrid1.TableStyles.Add(tableFormat)

End Sub

Re: DataGridView DataSource changing !!

kindman_nb6-Jan-07 23:35

kindman_nb

6-Jan-07 23:35

So sorry my friend and thanks for your reply
I didn't link the site from large period

The code above is worked with DataGrid , but i Use DataGridView
and I want any page that give full demonstration of DataGridView

jooooo

Graph implementation

maisa.sh2-Jan-07 10:47

maisa.sh

2-Jan-07 10:47

Is there any one know how to implement agraph in VB.NET???
PLZ i need it as soon as possible...

Re: Graph implementation

Colin Angus Mackay2-Jan-07 11:33

Colin Angus Mackay

2-Jan-07 11:33

maisa.sh wrote:
Is there any one know how to implement agraph in VB.NET???

Yes.

But it depends on how you want to use the graph. However, all solutions eventually come down to drawing on some kind of surface and for that you will need to learn about the Brush, Pen and Graphics classes (see MSDN)

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what is the problem about this code

nbulut2-Jan-07 10:00

nbulut

2-Jan-07 10:00

i wrote a querry sentence but there is a problem:
Syntax error (missing operator) in query expression 'like '%ç%''.
the sentence is :Dim querry As New OleDbCommand("select * from vtab where " & deger & " like '%" & Me.TextBox1.Text & "%'", baglanti)

Re: what is the problem about this code

Colin Angus Mackay2-Jan-07 11:28

Colin Angus Mackay

2-Jan-07 11:28

nbulut wrote:
OleDbCommand("select * from vtab where " & deger & " like '%" & Me.TextBox1.Text & "%'", baglanti)

Don't inject values in to a SQL statement. Use parameterised queries. Also, sanitise your input. You are injecting the value of the text box directly into the SQL. This blasts a huge security hole right through your application.

Read this article[^] and it will help you solve your current problem and plug the security holes in your code at the same time. Two for the price of one!

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Re: what is the problem about this code

nbulut2-Jan-07 12:02

nbulut

2-Jan-07 12:02

not sql the database is access is the article helpful for access

Re: what is the problem about this code

Colin Angus Mackay2-Jan-07 12:08

Colin Angus Mackay

2-Jan-07 12:08

nbulut wrote:
not sql the database is access is the article helpful for access

Do you mean you are not using "SQL Server". "SQL" is the language used to communicate with relational databases, which they all pretty much understand.

From the first paragraph of the article: "Although the technologies used here are SQL Server 2000 and the .NET Framework, the general ideas presented apply to any modern data driven application framework, which makes attacks potentially possible on any type of application that depends on that framework."

So, yes, it is still relevant to Access even although the examples may need to be tweaked slightly.

The main difference is that parameters in access are denoted by ? placeholders, rather than the specifically named parameters in SQL Server. This means that you must add the parameters to your query in the order in which the query encounters the ? placeholder.

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Re: what is the problem about this code

nbulut2-Jan-07 12:26

nbulut

2-Jan-07 12:26

can u give me an example
i am a beginner of progamming and my english is normal so i dont know what to do
i want to have the words which the user types in text box when u type the programme shows all the words in a list box which starts with a
oh i am sorry about asking too many simple questions Cry | :((

Re: what is the problem about this code

Colin Angus Mackay2-Jan-07 12:44

Colin Angus Mackay

2-Jan-07 12:44

I'm typing this directly so there may be some minor errors:

Dim someValue As String;
someValue = "%" & theTextBox.Text & "%"
myCommand.CommandText = "SELECT * FROM MyTable WHERE someColumn LIKE ?"
myCommand.Parameters.Add("?", someValue)

You may also wish to validate that the information the user has put in the text box is no longer than the length of the column, or check for any other conditions that make the value invalid before sending it to the database.

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how to resolve the over-writing problem of items in the list in vb.net

sushantsprajan2-Jan-07 7:55

sushantsprajan

2-Jan-07 7:55

Hi ,
i am using the following code where "_sessionCalibrationSessionMasterDTO" and "_calibrationSessionMasterDTO" are of same kind of objects having different properties.
/*
Dim _calibrationSessionMasterDTOs As IList(Of CalibrationSessionMasterDTO) = New List(Of CalibrationSessionMasterDTO)
Dim _calibrationSessionMasterDTO As CalibrationSessionMasterDTO = DTOFactory.GetNewCalibrationSessionmasterDTO()
*/

One of the property is "NoofSessions" and other one is "SessionNumber"
First of all i'm checking the following condition and based on it i'm adding the "_calibrationSessionMasterDTO" into a list of same kind of object "_calibrationSessionMasterDTOs"

For _count As Integer = 1 To _sessionCalibrationSessionMasterDTO.NoofSessions
_calibrationSessionMasterDTO.SessionNumber = _count
_calibrationSessionMasterDTOs.Add(_calibrationSessionMasterDTO)
Next

Now the main problem is that for _count = 1 its working fine (there is no previous member) but as soon as _count increases the previous member of list _calibrationSessionMasterDTOs are updating with the latest one.

I have tried to initialize the object _calibrationSessionMasterDTO every time before adding it to the list but nothing happened.

I have also tried to insert these values instead of adding but nothing happened.

For example if _count = 1 and _calibrationSessionMasterDTO.SessionNumber = 1 then this loop is working fine.
but for _count=2 and _calibrationSessionMasterDTO.SessionNumber = 2 then
the previous value of _calibrationSessionMasterDTO.SessionNumber is updated by the latest one i.e. 1 is updated by 2...

please help me if any one having any idea...
If you can reply at earliest then it wud be gr8

Re: how to resolve the over-writing problem of items in the list in vb.net

Dave Kreskowiak2-Jan-07 9:13

Dave Kreskowiak

2-Jan-07 9:13

Your new creating a new _calibrationSessionMasterDTO object before you add it to the collection. You're modifying the existing one and re-adding it over and over again. Change it to:

For _count As Integer = 1 To _sessionCalibrationSessionMasterDTO.NoofSessions
    Dim newobj As CalibrationSessionMasterDTO = DTOFactory.GetNewCalibrationSessionmasterDTO()
    newobj.SessionNumber = _count
    _calibrationSessionMasterDTOs.Add(newobj)
Next

Dave Kreskowiak
Microsoft MVP - Visual Basic

Re: MySql connection

Dave Kreskowiak2-Jan-07 9:09

Dave Kreskowiak

2-Jan-07 9:09

jds1207 wrote:
("Provider=MySQLProv;Data Source=testship;User Id=jsimmonsassword=dway1207;")

Thanks for the username and password! (You might want to remove those from future posts.)

jds1207 wrote:
Dim conn As New OleDb.OleDbCommand("", myConnString)
conn.Connection.Open()

Dim read As OleDb.OleDbDataReader = conn.ExecuteReader(CommandBehavior.CloseConnection)

You created an OleDbCommand object, but didn't give it an SQL statement to execute before you called ExecuteReader on it. The reader object won't work without it.

Dave Kreskowiak
Microsoft MVP - Visual Basic

Picture Box Control

bjeverett2-Jan-07 6:24

bjeverett

2-Jan-07 6:24

Anyone know of a control similar to a picture box but with clipping and stretching capability? I need a quick fix.

Thanks.

B.J.

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