Keep DataGridView data after closing, without database

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Keep DataGridView data after closing, without database

M B 41

Hello,
please, is there any way how to save data that are in DataGridView when it's not connected to DB?

When I close the form and open it again, it should be still the same as before closing.

I'm a noob, I finally made a form with everything that I need but need this last thing.
This is my table:

Public Class Form1

    Dim table As New DataTable("Table")

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect

        table.Columns.Add("Date", Type.GetType("System.DateTime"))
        table.Columns.Add("Code", Type.GetType("System.String"))
        table.Columns.Add("Position", Type.GetType("System.String"))
        table.Columns.Add("Note", Type.GetType("System.String"))
        table.Columns.Add("Solved", Type.GetType("System.DateTime"))

        DataGridView1.DataSource = table


    End Sub

Can anyone post me any code to do that?
Thanks

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Answer 1

Viorel 122.6K

Initially try a simple approach like this:

Dim table As New DataTable("Table")
ReadOnly p As String = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "mydata.xml")

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

   DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect

   If Not File.Exists(p) Then
      table.Columns.Add("Date", Type.GetType("System.DateTime"))
      table.Columns.Add("Code", Type.GetType("System.String"))
      table.Columns.Add("Position", Type.GetType("System.String"))
      table.Columns.Add("Note", Type.GetType("System.String"))
      table.Columns.Add("Solved", Type.GetType("System.DateTime"))
   Else
      table.ReadXml(p)
   End If

   DataGridView1.DataSource = table

End Sub

Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing

   table.WriteXml(p, XmlWriteMode.WriteSchema)

End Sub

M B 41

Wow, thanks :-) .
One more question, this your code works, but I also have a button that marks solved row like this

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

        DataGridView1.CurrentRow.DefaultCellStyle.BackColor = Color.PaleGreen

        DataGridView1.CurrentRow.Cells("Solved").Value = DateTimePicker1.Value

        DataGridView1.DataSource = table

        DataGridView1.ClearSelection()

    End Sub

When I reopen the form, the value is still there but not the green background. Any idea? :-)

Viorel 122.6K

As an exception, try something like this:

Private Sub DataGridView1_CellFormatting(sender As Object, e As DataGridViewCellFormattingEventArgs) Handles DataGridView1.CellFormatting

   If e.RowIndex < table.Rows.Count AndAlso DataGridView1.Columns("Solved").Index = e.ColumnIndex AndAlso Not Convert.IsDBNull(e.Value) Then
      DataGridView1.Rows(e.RowIndex).DefaultCellStyle.BackColor = Color.PaleGreen
   End If

End Sub

M B 41 Reputation points

2021-05-03T11:03:22.437+00:00

I should maybe mention one more thing :-D I'm sorry.
This code that you posted changing all Solved rows to green.
When I have the same button, to remove data from the current row's cell Solved and change it back to white, what to add? This button is for something like: "Oops, I "Solved" the wrong row".

Your code looks more complicated than mine so I'm lost changing it to white when it's empty again :-) . I was expecting that I'll be able to just edit code to white but this is too much for me.

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Keep DataGridView data after closing, without database

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