How about SuspendLayout/ResumeLayout. When working with Listview and TreeView controls, you use BeginUpdate/endUpdate to suspend redrawing during updates. I haven't used Datagrid, but these methods appear to be similar.
Another possibility -- set the ResizeRedraw protected property to False while you are updating, and then set it back to true... Walt Crosby Terabase Corporation 10 Elm Street Danvers, MA 01923 (978) 774-7999 x114 -----Original Message----- From: Unmoderated discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] On Behalf Of Sandhya S Sent: Tuesday, December 21, 2004 2:20 AM To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: Re: [ADVANCED-DOTNET] Flickering of Datagrid. Tried Storing and restoring the position. It will work but then still the scroll bar goes to the first position while painting the new rows and then comes back to restored position. It looks as if the user is not able to control while the row is being added. We are having thousands of rows and in each row the progress bar being painted can take quite lot of time. In such scenario the scroll bar will keeps moving to the first row everytime the paint is invoked even though the user has given the new position. Regards Sandhya -----Original Message----- From: Vinod Kumar [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 21, 2004 12:25 PM To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: Re: [ADVANCED-DOTNET] Flickering of Datagrid. Exactly, What you can do is 1> store the position of the vertical scroll bar. 2> Add row 3> Restore the original position of the vertical scroll bar. Regards Vinod -----Original Message----- From: Unmoderated discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] On Behalf Of Sandhya S Sent: Tuesday, December 21, 2004 12:06 PM To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: [ADVANCED-DOTNET] Flickering of Datagrid. Hi, I have a custom data grid control which inherits from the data grid. The problem I am facing here is that the vertical scroll bar scrolls to the top (first row) each time a new row is added to the grid. But then I want the scroll bar to stay where it was before adding the row and should move only when the scroll bar is used by the user. The vertical scroll bar is visible once the no. of rows goes beyond the height of the grid. but then this is done automatically by the datagrid. There is no specific method written to scroll. Every time a row is added the paint method is invoked in which the base paint method of the grid paints from the first to the last row of the grid. Will this make the scroll bar to point to the first row ?? If so how can this be stopped ? Some more to add on Datagrid. The paint method of the datagrid is overidden in which the base paint method is invoked. Along with this a progress bar is also painted for one of the columns. But then there is too much of flicker while adding new rows. As the rows increase the flicker is more visible. The flicker was observed even without the paiting of the progress bar. That is even if we comment the paint method itself and allow the grid to take care of painting there is a lot of flicker. Can this flicker be stopped or reduced. This was developed on .Net Framework 1.1 Version 1.1.4322 with service pack SP1 installed. The overriden paint method : protected override void OnPaint(PaintEventArgs pe) { // If grid is disabled don't paint progress bar if(!this.Enabled) return; // If grid is not associated with any Data Source, then don't paint progress bar DataView dv = (DataView)this.DataSource; if(dv == null) return; // Copy the contents of DataView assoicated with grid to a DataTable System.Data.DataTable oTable = CreateTable(dv); //Perform base painting base.OnPaint(pe); try { // If no table, do nothing if(oTable == null) return; int nRow = 0; // For all the rows that are there in Grid call PaintProgressCell function int nCol = 4; // Index of column to be panited //int nColumn = 7; DataGrid.HitTestInfo hti = null; foreach(DataRow oRow in oTable.Rows) { if(oRow == null) continue; //get the cell bounds of the row and progress column. Rectangle rect1 = this.GetCellBounds(nRow, nCol); //Get the point of the rectangle for that row and column. Point p1 = new Point(rect1.X, rect1.Y); //get the hit test info of the point where grid is clicked. //In this situation the row and progress col to be painted. hti = this.HitTest(p1); //if the type of the row & column to be painted is a cell then go ahead. if (hti.Type == DataGrid.HitTestType.Cell) { //if it is the progress column to be painted then go ahead and paint the progress bar. if(nCol == hti.Column) PaintProgressCell(pe.Graphics, oRow, nRow, nCol); } nRow ++; } } catch(Exception e) { e.ToString(); } } Thanks & Regards Sandhya This message is free from Virus - IMSS =================================== This list is hosted by DevelopMentor(r) http://www.develop.com Some .NET courses you may be interested in: Essential .NET: building applications and components with C# November 29 - December 3, in Los Angeles http://www.develop.com/courses/edotnet View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentor(r) http://www.develop.com Some .NET courses you may be interested in: Essential .NET: building applications and components with C# November 29 - December 3, in Los Angeles http://www.develop.com/courses/edotnet View archives and manage your subscription(s) at http://discuss.develop.com This message is free from Virus - IMSS =================================== This list is hosted by DevelopMentor(r) http://www.develop.com Some .NET courses you may be interested in: Essential .NET: building applications and components with C# November 29 - December 3, in Los Angeles http://www.develop.com/courses/edotnet View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentorŪ http://www.develop.com Some .NET courses you may be interested in: Essential .NET: building applications and components with C# November 29 - December 3, in Los Angeles http://www.develop.com/courses/edotnet View archives and manage your subscription(s) at http://discuss.develop.com
