Formatting is slow in DataGridView than MSFlexgrid

Hi,

We have updated our application from VB 6 to VB.Net. We are using VS 2008. Now we are trying to convert MSFlexgrid used in our application to DataGridView. We are testing speed of both controls and we noticed that DataGridView is very much slow than MSFlexgrid while formatting cells(Changing background and foreground colour, making text bold etc).Its hard to use DataGridView if it is much slow. Why is DataGridView is slow while formatting? Is there any way to speed up?

Thank you

What exactly constitutes much slower? I can't say I've ever encountered any performance problems with the DGV itself so it's much more likely that any problems are in what you're doing with it and how you're doing it. Since you've chosen to give no information on that whatsoever it's next to impossible to suggest any improvements.

Quote:

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Originally Posted by dunfiddlin

What exactly constitutes much slower? I can't say I've ever encountered any performance problems with the DGV itself so it's much more likely that any problems are in what you're doing with it and how you're doing it. Since you've chosen to give no information on that whatsoever it's next to impossible to suggest any improvements.

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Ok, here is code i have used

Code:

---

Try

            Dim i As Integer
            Dim j As Integer
            Dim txtToAppend As String = ""
            Dim dstime As New DataSet
            Dim sqlcmd As DbCommand
            Dim rowcnt As Integer = InputBox("Please Enter RowCount", "DataSource")

            txtToAppend = DateAndTime.Timer
            Debug.Print(DateAndTime.Timer)
            sqlcmd = CommonObj.CommandObj(True)
            sqlcmd.Connection = getcon("Collections_Closed")
            sqlcmd.CommandText = "select top(" & rowcnt & ") * from collections"
            adapter.SelectCommand = sqlcmd
            adapter.Fill(dstime, "Collections")
            With DtdgDataSource
                .SuspendLayout()
                .DataSource = Nothing
                .AllowUserToAddRows = False
                .AllowUserToDeleteRows = False
                .AllowUserToResizeRows = False
                .AllowUserToOrderColumns = True
                .SelectionMode = DataGridViewSelectionMode.FullRowSelect
                .ReadOnly = True
                .MultiSelect = False
                .RowHeadersVisible = False
                .Columns.Clear()
                .Rows.Clear()
                .VirtualMode = True
            End With
            DtdgDataSource.GetType.InvokeMember("DoubleBuffered", Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance Or System.Reflection.BindingFlags.SetProperty, Nothing, DtdgDataSource, New Object() {True})
            DtdgDataSource.DataSource = dstime.Tables("Collections")
          For i = 0 To (rowcnt / 2)
                DtdgDataSource.Rows(i).DefaultCellStyle.BackColor = Color.LemonChiffon
            Next

            For i = 0 To DtdgDataSource.RowCount - 2
                For j = 2 To 7
                    DtdgDataSource.Rows(i).Cells(j).Style.ForeColor = Color.DarkOrange
                Next
            Next

            For i = 0 To DtdgDataSource.RowCount - 2
                For j = 8 To 13
                    DtdgDataSource.Rows(i).Cells(j).Style.Font = New Font(DtdgDataSource.Font, FontStyle.Bold)
                Next
            Next
        Catch ex As Exception
            MsgBox(Err.Description & vbTab & "Button3_Click")
        End Try

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Quote:

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Originally Posted by dunfiddlin

What exactly constitutes much slower? I can't say I've ever encountered any performance problems with the DGV itself so it's much more likely that any problems are in what you're doing with it and how you're doing it. Since you've chosen to give no information on that whatsoever it's next to impossible to suggest any improvements.

---

Ok, here is code i have used

Code:

---

Try

            Dim i As Integer
            Dim j As Integer
            Dim txtToAppend As String = ""
            Dim dstime As New DataSet
            Dim sqlcmd As DbCommand
            Dim rowcnt As Integer = InputBox("Please Enter RowCount", "DataSource")

            txtToAppend = DateAndTime.Timer
            Debug.Print(DateAndTime.Timer)
            sqlcmd = CommonObj.CommandObj(True)
            sqlcmd.Connection = getcon("Collections_Closed")
            sqlcmd.CommandText = "select top(" & rowcnt & ") * from collections"
            adapter.SelectCommand = sqlcmd
            adapter.Fill(dstime, "Collections")
            With DtdgDataSource
                .SuspendLayout()
                .DataSource = Nothing
                .AllowUserToAddRows = False
                .AllowUserToDeleteRows = False
                .AllowUserToResizeRows = False
                .AllowUserToOrderColumns = True
                .SelectionMode = DataGridViewSelectionMode.FullRowSelect
                .ReadOnly = True
                .MultiSelect = False
                .RowHeadersVisible = False
                .Columns.Clear()
                .Rows.Clear()
                .VirtualMode = True
            End With
            DtdgDataSource.GetType.InvokeMember("DoubleBuffered", Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance Or System.Reflection.BindingFlags.SetProperty, Nothing, DtdgDataSource, New Object() {True})
            DtdgDataSource.DataSource = dstime.Tables("Collections")
          For i = 0 To (rowcnt / 2)
                DtdgDataSource.Rows(i).DefaultCellStyle.BackColor = Color.LemonChiffon
            Next

            For i = 0 To DtdgDataSource.RowCount - 2
                For j = 2 To 7
                    DtdgDataSource.Rows(i).Cells(j).Style.ForeColor = Color.DarkOrange
                Next
            Next

            For i = 0 To DtdgDataSource.RowCount - 2
                For j = 8 To 13
                    DtdgDataSource.Rows(i).Cells(j).Style.Font = New Font(DtdgDataSource.Font, FontStyle.Bold)
                Next
            Next
        Catch ex As Exception
            MsgBox(Err.Description & vbTab & "Button3_Click")
        End Try

---

Please see if any thing i am misusing or any improvements can be made
Thank you

Quote:

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For i = 0 To DtdgDataSource.RowCount - 2
For j = 8 To 13
DtdgDataSource.Rows(i).Cells(j).Style.Font = New Font(DtdgDataSource.Font, FontStyle.Bold)
Next
Next

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The above code will create a new FONT object for each row, which will be slow.

Not sure if this would make a difference, but just give it a try:

Code:

---

          Dim myFont as New Font(DtdgDataSource.Font, FontStyle.Bold)
          For i = 0 To DtdgDataSource.RowCount - 2
                For j = 8 To 13
                    DtdgDataSource.Rows(i).Cells(j).Style.Font = myFont
                Next
            Next

---

Or, try this:

(not tested code)

Code:

---

        Dim myFont As New Font(DtdgDataSource.Font, FontStyle.Bold)
        For j = 8 To 13
            DtdgDataSource.Columns(j).DefaultCellStyle.Font = myFont
        Next

---

Quote:

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Originally Posted by Pradeep1210

The above code will create a new FONT object for each row, which will be slow.

Not sure if this would make a difference, but just give it a try:

Code:

---

          Dim myFont as New Font(DtdgDataSource.Font, FontStyle.Bold)
          For i = 0 To DtdgDataSource.RowCount - 2
                For j = 8 To 13
                    DtdgDataSource.Rows(i).Cells(j).Style.Font = myFont
                Next
            Next

---

---

Thanks for reply
Your suggestion will fasten the execution little,but its not enough,its still much slower than FlexGrid

What about post #6. Did you try that code?

I'm on a system at present where I can't test that code. But if that works, it would be much faster since it gets rid of the row-level looping. You may probably need to do that before binding the grid to datasource or it may work after data-binding.. not sure.

All the looping is taking the time away, especially the double loops. A lot of these changes can be made with a single command by using the columns as the basic unit rather than the cell, eg.

DataGridView1.Columns(0).DefaultCellStyle.ForeColor = Color.Orange

Then if you want single cells to vary from the column default you can do that for the individual cells rather than looping through setting every one. I have to say I don't really understand the purpose of..

For i = 0 To (rowcnt / 2)
DtdgDataSource.Rows(i).DefaultCellStyle.BackColor = Color.LemonChiffon
Next

Why would you want to divide the DGV in half arbitrarily?

Quote:

---

Originally Posted by Pradeep1210

What about post #6. Did you try that code?

I'm on a system at present where I can't test that code. But if that works, it would be much faster since it gets rid of the row-level looping. You may probably need to do that before binding the grid to datasource or it may work after data-binding.. not sure.

---

Thanks for reply
yes,that code fasten the execution a lot.But my problem is we are using same loops for flexgrid also,and its faster than DataGridView for same code. That i need to understand.Is there anything extra to do with DataGridView to speed up? And if i use DtdgDataSource.Rows(i).Cells(j).Style.Font = myFont the font setting will be applied to whole column, i cant do that if i need setting for only some rows of column. In latter case i have to use DtdgDataSource.Rows(i).Cells(j).Style.Font = myFont i think

Quote:

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Originally Posted by dunfiddlin

All the looping is taking the time away, especially the double loops. A lot of these changes can be made with a single command by using the columns as the basic unit rather than the cell, eg.

DataGridView1.Columns(0).DefaultCellStyle.ForeColor = Color.Orange

Then if you want single cells to vary from the column default you can do that for the individual cells rather than looping through setting every one. I have to say I don't really understand the purpose of..

For i = 0 To (rowcnt / 2)
DtdgDataSource.Rows(i).DefaultCellStyle.BackColor = Color.LemonChiffon
Next

Why would you want to divide the DGV in half arbitrarily?

---

Thanks for reply
yes,that code fasten the execution a lot. We used the code simply for testing. But my problem is we are using same loops for flexgrid also,and its faster than DataGridView for same code. That i need to understand.Is there anything extra to do with DataGridView to speed up?

Quote:

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Originally Posted by winman

Thanks for reply
yes,that code fasten the execution a lot. We used the code simply for testing. But my problem is we are using same loops for flexgrid also,and its faster than DataGridView for same code. That i need to understand.Is there anything extra to do with DataGridView to speed up?

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You must formating datagridview in zero rows result first.
For example :
Show data in 0 record result
Formating datagridview
Then show data you want to display.