Problem with DataGridView - Visual Basic Discussion Boards

how to unload and load a form?

Hello,
I'm not sure what you want is something like this:

Dim Newform1 as new Form1
Newform1.show() ' To Load a form

Newform1.Close() 'To Unload

'Or 

Newform1.Hide()  'To Unload

I just hope it helps you. Smile | :)

modified on Monday, February 23, 2009 1:17 AM

yes..dats rite!!..but the form will restart,rite?..i dont want the form to restart..
plss...help me..txx

Form.Close() will close the form, it will not restart.

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ya2..but actually i want to reset the form by unload n load back the form..can u help me?

Make your own reset method to reinitialize your objects and controls.

Check out the CodeProject forum Guidelines[^]

How many times are you going to ask the same question and ignore the answers you've been given?? There is no method to "reset" a form unless you write code to reset all of the values and controls you need, yourself.

If this is a child form you're talking about, all you need to do is create a new instance of the form, show it, get the values you need from it, then call Dispose on that instance. Every new instance you create will be created with the same initial values you specify in it's design and startup code.

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Hi all,I'm having problem here with my code. I would like to Update the Database with my DataGridView1 when Click the Button1. But from the code below,I found that an Error have occured.

Error from Visual Studio 2008= System.Data: Missing the DataColumn 'DO_No'in the DataTable 'Main_table' for the SourceColumn 'DO_No'.

The following are the code I load the data from database to my DataGridView1:

Private Sub MaintainDO_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ObjMyConn = New MySqlConnection(MyConnString)

       
        SQL = "SELECT * FROM main_table"
        Try

            ObjMyConn.Open()
            ObjAdapter = New MySqlDataAdapter(SQL, ObjMyConn)
            ObjComBuilder = New MySqlCommandBuilder(ObjAdapter)
            ds = New DataSet
            ObjAdapter.Fill(ds, "Main_table")
            dt = ds.Tables("Main_table")
            dt.Columns(0).ColumnName = "Date"
            dt.Columns(1).ColumnName = "DO No."
            dt.Columns(2).ColumnName = "Lorry No."
            dt.Columns(3).ColumnName = "Load From"
            dt.Columns(4).ColumnName = "To Site"
            dt.Columns(5).ColumnName = "Company Name"
            dt.Columns(6).ColumnName = "Item Description"

            DataGridView1.DataSource = dt.DataSet.Tables("Main_table")
            DataGridView1.Refresh()
        Catch ex As Exception
            MsgBox("Error: " & ex.Source & ": " & ex.Message, MsgBoxStyle.OkOnly)
        Finally
            ObjMyConn.Close()
        End Try
    End Sub

The code I put inside my Button1:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        
        SQL = "SELECT * FROM main_table"
        Try
            ObjAdapter.Update(ds.Tables("Main_table")) '<< Here is how I used to update my database.

            ds.Tables("Main_table").Clear()
            DataGridView1.DataSource = Nothing
            DataGridView1.Refresh()

            ObjMyConn.Open()
            ObjAdapter = New MySqlDataAdapter(SQL, ObjMyConn)
            ObjComBuilder = New MySqlCommandBuilder(ObjAdapter)
            ObjAdapter.Fill(ds, "Main_table")
            dt = ds.Tables("Main_table")

            dt.Columns(0).ColumnName = "Date"
            dt.Columns(1).ColumnName = "DO No."
            dt.Columns(2).ColumnName = "Lorry No."
            dt.Columns(3).ColumnName = "Load From"
            dt.Columns(4).ColumnName = "To Site"
            dt.Columns(5).ColumnName = "Company Name"
            dt.Columns(6).ColumnName = "Item Description"

            DataGridView1.DataSource = ds.Tables("Main_table")
            DataGridView1.Refresh()
        Catch ex As Exception
            MsgBox("Error: " & ex.Source & ": " & ex.Message, MsgBoxStyle.OkOnly)
        Finally
            ObjMyConn.Close()
        End Try


    End Sub

Besides,I have a few other question to know more about my coding style suits my need of the project. This are my question:
1. Am I using a right way to put the data into the datagridview? Any other way is better for me to control the data inside the datagridview?
2. If I need to add another column which shows abit calculation (suck like column1 x column2=>>new column9)into the datagridview,how should I do?

Thanks for reading my post,hope someone can give me some sample for this solution. Thank you again~!

OK. I think it's pretty obvious just by reading the error message. You're missing a column in your DataTable("Main_table") that you included in your SQL statement.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Thanks Mr. Dave,I have solve the problem. I make a mistaken on the DataGridView1.Column1 header name. So I change it to the original name and it works now.

Thanks alot to Mr. Dave and everyone reading here.

Regards Smile | :)

Drex

hii all..how to type a label vertically?

Change the label to a graphic and rotate the graphic

Never underestimate the power of human stupidity
RAH

http://www.codeproject.com/KB/vb/vertical_label.aspx[^]

http://www.codeproject.com/KB/miscctrl/Vertical_Label_Control.aspx[^]

next time please search the articles first (or Google first)

actually i want to do is the label can be display like this:

L
A
B
E
L
1

instead of LABEL1

by the way..thanks alot for your help.. Smile | :)

well I'm sure you can alter the code from those articles.

My first idea would be to make a custom control inherited from label.
Then on the textchanged event set the height of the label (and width)
Then draw the every letter (make an array with the split function) on the control.
Haven't done it myself but it shouldn't be that hard to do.
If I have time I'll see what I can come up with once I'm home

oke thanks..but i dnt know how to do that.. Frown | :(

,but i will try tonite,,thanks alots,,have a nice day!!!

Public Class VerticalLabel
    Inherits Label

    Public Sub New()
        Me.AutoSize = False
    End Sub
    Public Overrides Property AutoSize() As Boolean
        Get
            Return MyBase.AutoSize
        End Get
        Set(ByVal value As Boolean)
            MyBase.AutoSize = False
        End Set
    End Property

    Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs)
        Dim graphics As Graphics = e.Graphics
        Dim text As String = Me.Text
        Dim width As Integer = 0
        Dim height As Integer = 0
        Dim textBrush As Brush = New SolidBrush(Me.ForeColor)
        For Each c As Char In text.ToCharArray()
            Dim sw As Single = graphics.MeasureString(c, Me.Font).Width
            If sw > width Then
                width = sw
            End If
            Dim sh As Single = graphics.MeasureString(c, Me.Font).Height
            height += sh
            graphics.DrawString(c, Me.Font, textBrush, 0, height - sh)
        Next
        Me.Width = width
        Me.Height = height + 2
    End Sub

    Private Sub VerticalLabel_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.TextChanged
        Me.Refresh()
    End Sub
End Class

This should do what you want (very basic so you might want to add a bit, like an option to set it to vertical or horizontal,...)

oke, how about multiple label???

????? multiple label?

I gave you a custom control just copy past the code into an empty class file.
Build you solution and you'll have an extra control in you toolbox which you then can drag onto you form as many times as you want

Just rotate the monitor 90° right. Roll eyes | :rolleyes:

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Actually still wouldn't solve his problem but still funny Poke tongue | ;-P

look at this...

Application.Restart()

if i use this,the application will restart..but i dnt want the application to restart?
any idea?..plss..txxx.. Smile | :)

You would need to write a Reset method that manually re initialises all your objects and variables

Never underestimate the power of human stupidity
RAH

Why are you reposting same question[^]? Mad | :mad:

The word "politics" describes the process so well: "Poli" in Latin meaning "many" and "tics" meaning "bloodsucking creatures."

जय हिंद

hi ,

i have a question about events in vb.net ,
im looking for a similar functionality to c# event registering ,
like how could i "unregister" an event during run time and then register it back.

for example in c#

myclass.myEvent -= new MyEvent(myHabdler);

[code block , that i dont want the event will fire]

myclass.myEvent += new MyEvent(myHabdler);

thank you for your time!

Net