Re: object reference not set to an instance of an object - Visual Basic Discussion Boards

MP9123-Jul-07 21:34

23-Jul-07 21:34

I am creating deployment setup for windows based application by cutomising deployment project, using User Interface editor and Custom Action editor.
In my custome action i want to know the path(location) at which this application is being install.
Basically when setup program runs the first screen pop's up and ask user to select the location to install the application. This path i want to access in my later custom actions.

If any one knows how, please kindly let me know. I appreciate your help.
Thank you very much.

General problem creating a UserControl

gilchinger23-Jul-07 21:08

gilchinger

23-Jul-07 21:08

Hi forum,

i like to create a UserControl with some textboxes, buttons and so on.

This is no problem, starting with a UserControl project, placing the textboxs, buttons on the control panel, compiling, adding the dll to any project. It works perfect.

My problem now is: Placing MyUserControl on any form, it is possible to code in the calling form MyUserControl.Controls.Items(...).... to get a collection of controls.

Using this collection, it's possible to get direct access to all controls placed on MyUserControl.

Who to prevent direct access from any forms to the controles placed on the MyUserControl using the Controls Collection ?

Any comments pls ?

Re: General problem creating a UserControl

Christian Graus23-Jul-07 23:19

Christian Graus

23-Jul-07 23:19

There's really no way to stop people accessing your controls this way. Why would you want there to be ? I mean, if someone starts manipulating the controls on your control, then that's their problem.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Re: General problem creating a UserControl

gilchinger24-Jul-07 0:23

gilchinger

24-Jul-07 0:23

Thank you for your quick reply, this answer i expected, after some testing, that there is no way.

Why to prevent modifying the control - well, isn't a control just some code for any specific task? Istn't it better to prevent modifyiny?

But ok, you are right, people modifying an control my be it's there problem .....

Crystal Report in Picturebox

ShuklaGirish23-Jul-07 20:52

ShuklaGirish

23-Jul-07 20:52

Hello Friends,
I am creating one vb6.0 project and i have the reqirement to display Crystal Report in Picturebox,so can anyone tell me how this is possible pls send me te code to dispay Crystal report on picturebox control in vb 6.0.

Thanks and Regards,
Girish B, Shukla

GIRISH

Re: Crystal Report in Picturebox

Christian Graus23-Jul-07 20:57

Christian Graus

23-Jul-07 20:57

A picturebox shows a picture. Therefore, you need to render your report to a bitmap, then you can put that bitmap in a picturebox.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

object reference not set to an instance of an object

Prem Ranjan23-Jul-07 20:41

Prem Ranjan

23-Jul-07 20:41

hi! i am using vb.net 2003. but now i have started getting an error "object reference not set to an instance of an object" and that too as soon as i start coding. as soon as i enter the editor, the first thing i do select an "oledb connection control" from the toolbox. and next in the property tab of the oledbconnection, as soon as i select the connectionstring value, the abovementioned error occurs. i just can't understand y this is happening as i haven't even started coding! ne1 ever encountered this error b4???

Re: object reference not set to an instance of an object

Christian Graus23-Jul-07 20:56

Christian Graus

23-Jul-07 20:56

Prem Ranjan wrote:
ne1 ever encountered this error b4???

Please stick to English...

What you can do is open a second instance of the IDE, attach the debugger to the first instance, and see where you end up when it crashes.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Re: object reference not set to an instance of an object

Paul Conrad23-Jul-07 20:59

Paul Conrad

23-Jul-07 20:59

Christian Graus wrote:
stick to English...

Text speak is turned off right now...b4 didn't compile for a minute there Roll eyes | :rolleyes:

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

string issue

Tauseef A23-Jul-07 17:53

Tauseef A

23-Jul-07 17:53

hi guys

i have a string
like "12007" or "112007"

in this string last four characters denotes to a specific year and the rest shows month ,

i want to get a the month either ir is 1 or 12 or 10 ,, i cannot use sunstring because i am not sure about its lenth it might me 1 or two , so how could i get the exazct month ,,,
thansk in advance

hello

Re: string issue

Paul Conrad23-Jul-07 18:49

Paul Conrad

23-Jul-07 18:49

Unless someone sticks the day of the month in there, then you got some trouble.

You have to assume that the last four are the year, then anything before that is going to be the month. Assuming the day of month isn't going to be there, you will have to check the length of the string. If it is 5 then you have one digit for the month, else if the length is 6, then you have two digits for the month. Find the length of the string first, then you can use SubString(....) to pick it apart.

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

Re: string issue

Ray Cassick23-Jul-07 18:50

Ray Cassick

23-Jul-07 18:50

Why not look at the total length of the string then subtract 4 (the number of digits for the year portion) and use that data to know the rest?

Its just working backwards.

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Re: string issue

Luc Pattyn24-Jul-07 2:27

Luc Pattyn

24-Jul-07 2:27

chop last 4 chars and parse, I would say.

Luc Pattyn

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Filling a DataGrid without a DataSource

ford8623-Jul-07 17:10

ford86

23-Jul-07 17:10

Can someone please help me filling a DataGrid without a DataSource. I'm used to work with a component called the True DBGrid made by ComponentOne for VB6, and it was a walk in the park to change the cells' value. Surely there's a way to modify the values without a source, right?

Thanks in advance!

Re: Filling a DataGrid without a DataSource

RichardBerry23-Jul-07 23:56

RichardBerry

23-Jul-07 23:56

I Don't know if I understand your question correcly, but if you are using VS2005, and a DataGridView control, you can do this:

'Drop the control on your form
'Add two columns
Me.DataGridView1.Columns.Add("Col1", "FirstColName")
Me.DataGridView1.Columns.Add("Col2", "SecondColName")

'Add some rows - 5 in this case
Me.DataGridView1.Rows.Add(5)

'Modify the Data in the control
Me.DataGridView1.Item(0, 0).Value = "Hello" 'Row 0, Column 0
Me.DataGridView1.Item(0, 1).Value = "Dude" 'Row 1, Column 0

Re: Filling a DataGrid without a DataSource

Dave Kreskowiak24-Jul-07 1:53

Dave Kreskowiak

24-Jul-07 1:53

You could do how Richard described, but if you're going to save the data in the grdi, you'd be better off binding the grid to a DataTable you create. The DataTable object can save, and load, the data into/from an XML file without a pile of code on your part.

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Code Explanation

ASPnoob23-Jul-07 15:35

ASPnoob

23-Jul-07 15:35

Hi, would you please explain the two lines of code below that are high lighted.

DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter(qry, con);
da.Fill(ds);

ListBox1.DataSource = ds;

ListBox1.DataValueField = "SingerID"; //this will associate the ID to the items in the listbox
ListBox1.DataTextField = "Singer"; //this will display the names of singers

ListBox1.DataBind();

Are "SingerID" and "Singer" the names of fields in a database. The comment to the right of "Singer"; says that the name of singers will be displayed. How will it be displayed, in grid or something else? Thanks for your help.

Re: Code Explanation

Paul Conrad23-Jul-07 15:54

Paul Conrad

23-Jul-07 15:54

SingerID is the id (probably primary key) of the Singer, and Singer contains the text of the name. What happens is if the user selects a name from the listbox, then the SelectedValue property of the listbox is the corresponding SingerID for that particular name.

"I've seen more information on a frickin' sticky note!" - Dave Kreskowiak

Re: Code Explanation [modified]

ASPnoob23-Jul-07 16:08

ASPnoob

23-Jul-07 16:08

Suppose instead of having Singer and SingerID as the names of the fields in the database, I have ResumeID and Resumes as the names, and Resumes contains resumes of different people. Can I use the same technique that was used to display the content Singer to display the content of Resumes if Resumes is of type nvarchar or text? Thanks for responding.

-- modified at 22:32 Monday 23rd July, 2007

Re: Code Explanation

Paul Conrad23-Jul-07 16:31

Paul Conrad

23-Jul-07 16:31

Singer looks as if it is the field in the database holding the names of the singers. In your case, you can change SingerID to ResumeID, and Singer to Resumes. It should work.

"I've seen more information on a frickin' sticky note!" - Dave Kreskowiak

Re: Code Explanation

ASPnoob23-Jul-07 18:13

ASPnoob

23-Jul-07 18:13

Hi, please help I've been wrestling with this for a very long time and its not working. The following is my code.

<br />
<br />
    Private Sub ListBox2_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox2.SelectedIndexChanged<br />
<br />
        Dim myCon As OdbcConnection<br />
        Dim i As Integer<br />
        Dim cmd As OdbcCommand<br />
        For i = 0 To ListBox2.Items.Count - 1<br />
            If ListBox2.Items(i).Selected Then<br />
<br />
                myCon = New OdbcConnection("Driver={MySQL ODBC 3.51 Driver};Server=myServer;Database=myDatabase;User=myUserassword=myPass;Option=3;")<br />
                cmd = New OdbcCommand("SELECT * FROM myTable where Professions = '" & ListBox2.Items(i).Text & "'")<br />
<br />
            End If<br />
        Next<br />
        If Not IsNothing(myCon) Then<br />
            myCon.Open()<br />
<br />
            cmd.Connection = myCon<br />
<br />
            Dim ds As New DataSet<br />
<br />
            Dim ad As New OdbcDataAdapter(cmd)<br />
<br />
            ad.Fill(ds)<br />
<br />
            Me.ListBox2.DataSource = ds<br />
<br />
            Me.ListBox2.DataTextField = "ResumesID"<br />
            Me.ListBox2.DataTextField = "Resumes"<br />
            Me.ListBox2.DataBind()<br />
<br />
        End If<br />
    End Sub<br />

Re: Code Explanation

Paul Conrad23-Jul-07 18:19

Paul Conrad

23-Jul-07 18:19

ASPnoob wrote:
User=myUserassword=myPass;

This might be your problem. Please describe the error you are having.

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

Re: Code Explanation

Psycho-^*Coder*-Extreme23-Jul-07 19:15

Psycho-^*Coder*-Extreme

23-Jul-07 19:15

ASPnoob wrote:
Me.ListBox2.DataTextField = "ResumesID"
Me.ListBox2.DataTextField = "Resumes"

For starters you're setting the DataTextField 2 times. Once should be DataTextField (Resumes) and the other should be DataValueField (ResumeID)

"It's only that urgent if you have to pee."
Dave Kreskowiak

Re: Code Explanation

Paul Conrad23-Jul-07 20:21

Paul Conrad

23-Jul-07 20:21

Psycho-*Coder*-Extreme wrote:
For starters you're setting the DataTextField 2 times

Oops, how did I miss that one? Blush | :O

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

Re: Code Explanation

Psycho-^*Coder*-Extreme23-Jul-07 20:23

Psycho-^*Coder*-Extreme

23-Jul-07 20:23

Paul Conrad wrote:
Oops, how did I miss that one?

Not enough coffee? D'Oh! | :doh:

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