Visual Basic

Datagridview not showing my list(of object)

9-Feb-12 22:53

He's after earlier than that! VB6

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Sonhospa8-Feb-12 8:22

Sonhospa

8-Feb-12 8:22

Hi everybody,

I want to populate a datagridview with a generic list(of object), and from different sources I have 2 ways to do so, either

dataGridView1.DataSource = list

or (after binding the datagridview to a bindingsource)

Bindingsource1.Datasource = list

Unfortunately both ways won't work for me, and I wonder why. Either way I tried, I refreshed the datagridview afterwards and also controlled that the list was definitely populated.

Does anyone have an idea what might be wrong in my approach?

Thank you
Mick

(Resolved): Datagridview not showing my list(of object)

Luc Pattyn8-Feb-12 9:30

Luc Pattyn

8-Feb-12 9:30

I know of two ways to get a DGV automatically display a collection of data:

1.
stuff the data in a DataTable, then simply establish a binding between DT and DGV. Once the DT is fully populated, the DGV columns, their HeaderText, Width, etc are all set automatically.

2.
or have a collection of some type (not: object) with a number of public properties, then give the DGV a number of columns and bind each column to a property of the type in the collection, using DataGridViewColumn.DataPropertyName[^]

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Fed up by FireFox memory leaks I switched to Opera and now CP doesn't perform its paste magic, so links will not be offered. Sorry.

Sonhospa10-Feb-12 0:36

Sonhospa

10-Feb-12 0:36

Hi Luc,

thank you for your hints Cool | :cool:

. I tried both ways, and after a little bit of fiddling I could make either way work. On the way I found an interesting piece of code (how to convert a generic list into a datatable[^]), which might also be interesting for others.

Have a nice weekend, regards
Mick

Re: (Resolved): Datagridview not showing my list(of object)

Luc Pattyn10-Feb-12 1:01

Luc Pattyn

10-Feb-12 1:01

you're welcome.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Fed up by FireFox memory leaks I switched to Opera and now CP doesn't perform its paste magic, so links will not be offered. Sorry.

Simon_Whale9-Feb-12 22:58

9-Feb-12 22:58

The class that is in the list, is it using public variables i.e.

public class foobar
 public id as integer = 0
 public name as string = string.empty
end class

if so I dont know why it does it but that always leaves the gridview empty until your define properties e.g.

public class foobar
 private _id as integer = 0
 private _name as string = string.empty

 public property ID as integer
  'get set here
 end property

 public property Name as string
 end property
end class

Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch

Luc Pattyn9-Feb-12 23:38

Luc Pattyn

9-Feb-12 23:38

Data binding uses reflection, it looks for properties with the specified names.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Fed up by FireFox memory leaks I switched to Opera and now CP doesn't perform its paste magic, so links will not be offered. Sorry.

Simon_Whale9-Feb-12 23:44

(Resolved): Datagridview not showing my list(of object)

9-Feb-12 23:44

Thanks Luc Smile | :)

Thats my something learnt for today now I'm off to make snow angels Laugh | :laugh:

Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch

Sonhospa10-Feb-12 0:40

Sonhospa

10-Feb-12 0:40

Thank you, Simon - this was exactly one of my basic errors! After defining properties instead of the fields in the class, everything worked out.

Have a nice weekend with a lot of snow angels and Java | [Coffee]

, regards
Mick

Re: (Resolved): Datagridview not showing my list(of object)

Simon_Whale10-Feb-12 1:07

10-Feb-12 1:07

Your welcome Michael and have a good weekend yourself Smile | :)

Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch

Diamond Looping

Framework .l.7-Feb-12 14:51

Framework .l.

7-Feb-12 14:51

hi, i'm trying to do a looping like this,
if i input 5 then,

my teacher code structure is like below,
confuse level : 99999

for (loop the row)
   select case
      case 1
         for
            if
            end if
         next
      case 2
         if
         end if
   end case
next

what i do,

Private Sub btnView1_Click(sender As System.Object, e As System.EventArgs) Handles btnView1.Click
        Dim input As Integer = Nothing

        Dim spaces As String = Nothing
        Dim numbers As String = Nothing
        '##INPUT
        input = CInt(InputBox("Insert Max Value", "Value"))

        For a As Integer = 1 To (input * 2) - 1
            '##SPACES
            If a <= input Then
                For b As Integer = 1 To (input - a)
                    spaces += " "
                Next
            Else
                For b As Integer = 1 To (a - input)
                    spaces += " "
                Next
            End If
            '##NUMBERS
            If a <= input Then
                For c As Integer = 1 To a
                    numbers += c.ToString()
                Next
            Else
                For c As Integer = 1 To ???
                    numbers += c.ToString()
                Next
            End If
            '##OUTPUT
            ListBox1.Items.Add(spaces + numbers)
            spaces = ""
            numbers = ""
        Next
    End Sub

can someone correct '???' in my code?
thanks before.. Laugh | :laugh:

modified 7-Feb-12 22:14pm.

Johan Hakkesteegt7-Feb-12 21:18

Johan Hakkesteegt

7-Feb-12 21:18

Are you getting an error, or is the output not what you expect ?

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

Simon_Whale8-Feb-12 0:46

8-Feb-12 0:46

??? = a step -1

but that will only give you half of the diamond

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hansoctantan9-Feb-12 3:55

hansoctantan

9-Feb-12 3:55

I try this in vb6 and it really a nice code

Private Sub Command1_Click()
        List1.Clear
        Dim inp As Integer
        Dim spaces As String
        Dim numbers As String
        '##INPUT
        inp = CInt(InputBox("Insert Max Value", "Value"))
        Dim a As Integer
        Dim b As Integer
        Dim c As Integer
        For a = 1 To (inp * 2) - 1
            '##SPACES
            If a <= inp Then
                For b = 1 To (inp - a)
                    spaces = spaces + " "
                Next
            Else
                For b = 1 To (a - inp)
                    spaces = spaces + " "
                Next
            End If
            '##NUMBERS
            If a <= inp Then
                For c = 1 To a
                    numbers = numbers & c
                Next
            Else
                For c = 1 To (inp * 2) - a
                    numbers = numbers & c
                Next
            End If
            '##OUTPUT
            List1.AddItem spaces + numbers
            spaces = ""
            numbers = ""
        Next
End Sub

Framework .l.9-Feb-12 14:14

Framework .l.

9-Feb-12 14:14

well thankyou very much, but i hope you don't use that anymore..
vb6 is in it's way to hell..
once again, thankyou for the logic.. Thumbs Up | :thumbsup:

access uniquetable

C#Coudou6-Feb-12 18:31

6-Feb-12 18:31

Apologize if I post this on the wrong forum.

In ACCESS, I have Form Open event
that will connect to DB1 and datas will show on the detail records.

The form has a Uniquetable = "tableEmp".

Now, I have a option button that will
change database to DB2,

Note: DB1 and DB2 all tables are the same.

In the form details I have checkbox, if I
will checked the checkbox the tables update automatically,
and it will update because of the uniquetable but If
I will change the database the tables will not update.
what's cause of this? thanks in advance,.

C# コードMicrosoft End User
2000-2008

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Abhinav S6-Feb-12 19:12

Abhinav S

6-Feb-12 19:12

Check if the database db2 has the same table.
If it does, the primary key that you update the table on may not be present in this table (in the second database).

C#Coudou6-Feb-12 20:40

6-Feb-12 20:40

thanks. i check the db2 and it has the same table.

is my approach correct?
i mean connecting other database in an access form.

here is my snippet code: ACCESS FORM

'Default database DB1
Private Sub Form_Open(Cancel As Integer)
   Dim ssql As String
 
    ssql = "SELECT [tbl1].id, [tbl1].code,[tbl1].mflag, [tbl2].cdnum, [tbl3].bname"
    ssql = ssql & " FROM  [tbl1] INNER JOIN"
    ssql = ssql & " [tbl2] ON"
    ssql = ssql & " [tbl1].id = [tbl2].id INNER JOIN"
    ssql = ssql & " [tbl3] ON [tbl1].code = [tbl3].code"
    ssql = ssql & " WHERE [tbl1].mdate ='2011/10/12'"
    Me.RecordSource = ssql
    
    Me.UniqueTable = "tbl2"

End Sub

'option to select DB1 or DB2
Private Sub optSel_AfterUpdate()
    Dim ssql As String
    
    'DB1
    If Me.optSel = 1 Then
        ssql = "SELECT [tbl1].id, [tbl1].code,[tbl1].mflag, [tbl2].cdnum, [tbl3].bname"
        ssql = ssql & " FROM  [tbl1] INNER JOIN"
        ssql = ssql & " [tbl2] ON"
        ssql = ssql & " [tbl1].id = [tbl2].id INNER JOIN"
        ssql = ssql & " [tbl3] ON [tbl1].code = [tbl3].code"
        ssql = ssql & " WHERE [tbl1].mdate ='2011/10/12'"      
    Else 'DB2
        ADODisconn 'disconnect to DB1
     
        ADOConDB2  'connect to DB2        
        
         ssql = "SELECT [tbl2].id,[tbl2].code,[tbl2].mflag,[tbl2].cdnum,[tbl3].bname"
         ssql = ssql & " FROM  [tbl2] INNER JOIN [tbl3] ON "
         ssql = ssql & " [tbl2].code = [tbl3].code"
         ssql = ssql & " WHERE [tbl2].id > 160" 
    End If

   Me.RecordSource = ssql
   Me.UniqueTable = "tbl2"

End Sub

Abhinav S6-Feb-12 21:34

Abhinav S

6-Feb-12 21:34

There is no UPDATE query in this code so its really difficult to figure out.

C#Coudou6-Feb-12 22:07

6-Feb-12 22:07

no. the update is on the form.
Using the Continuous Forms

The same as GridiView in visual basic.

In detail of continuous form, I have textboxes and checkboxes, if I check the checkbox,
the table is automatically updated. Database update is not on the code, its on the form.

Eddy Vluggen7-Feb-12 7:41

Eddy Vluggen

7-Feb-12 7:41

C#Coudou wrote:
is my approach correct?

i mean connecting other database in an access form.

here is my snippet code: ACCESS FORM

It looks like VB.NET, but I don't see any OleDbCommand's. Are you using the "old" recordsets?

FWIW; I don't see any code where you bind the data to the UI, nor where you re-open the new connection. The best suggestion I can give is to use the OleDb provider to access your database.

Bastard Programmer from Hell Suspicious | :suss:

C#Coudou7-Feb-12 13:41

7-Feb-12 13:41

nope, this is not vb.net, this is MS Access, that is why you cannot see an oledbcommand.yes, I'm using old recordsets.
You can't see open connection because in the Form1 properties, it has recordsource, also in form open.

If i will use oledb connection, how can i add the data's in my continuous form?
This project is an .adp(microsoft access project),which means if you open the myproject.adp, it is already connected to database.