DataGrid repaint problem

Question

Hi Guys I am trying to change a value in a particular cell with different color. For this I tried an example from MSDN in which the author implements a calss that inherits from DataGridTextBoxColumn with only one method PaintCol(g cellRect cm hi.Row bBrush fBrush false); that in turn calls the base class paint method with my desired text and backGround color. The function call prints the text with the specified color but soon after because of the implicit call to the paint method the cell repaint with the default color. Could anybody know how to do so.

Andrzej Wegierski · Answer

CurrencyManger (src) has a property List. It's a DataView of table which You are using. Cast it to DataView.

malik.aamir · Answer

I am still having problem accessing dataTable. I dont have the dataTable in this scope. Then how can I access my old values. The dataTable is in my object of Form class and I want to access it from one of my class that is Inherited from DataGridTextBoxColumn. Please help me out of this problem.

Andrzej Wegierski · Answer

Use (for third column): string newtxt=this.GetColumnValueAtRow(srcrow); if(row==1 && newtxt>oldtxt) bb=... instead of: if(row%2==1) bb=new SolidBrush(Color.FromArgb(227227227)); else bb=new SolidBrush(Color.FromArgb(234234234)); Try to get oldtxt from Your data source: string oldtxt=myDataTable.DefaultView[row][column3].ToString(); etc.

malik.aamir · Answer

I have tried these examples but these examples are not completing my requirements. I have to change the cell value and color on the basis of cells previous value. For example I have to change the first row and third column with 10 when this cell contains the value 5 previously. I have to change the color of the cell on the basis of 1st value. If the new value is greater than the previous one then The color of cell should change. PLease tell me how to change the value of one cell on the basis of its previous value.

Andrzej Wegierski · Answer

I didn't seen PaintCol example but I use from long time similar methods in inherited DataGridColumnStyle (WinForfm): protected override void Paint(Graphics grRectangle bndCurrencyManager srcint rowBrush bbBrush fbbool algn) { if(((SolidBrush)bb).Color!=this.DataGridTableStyle.SelectionBackColor && ...something...) { if(row%2==1) bb=new SolidBrush(Color.FromArgb(227227227)); else bb=new SolidBrush(Color.FromArgb(234234234)); } this.PaintText(grbndtxtbbfbalgn); } protected override void Paint(Graphics gRectangle bndCurrencyManager srcint rowbool algn) { Brush bb=new SolidBrush(this.DataGridTableStyle.BackColor); Brush fb=new SolidBrush(this.DataGridTableStyle.ForeColor); this.Paint(gbndsrcrowbbfbalgn); } protected override void Paint(Graphics gRectangle bndCurrencyManager srcint row) { this.Paint(gbndsrcrowfalse); } private void PaintText(Graphics grRectangle bndstring txtBrush bbBrush fbbool rtl) { StringFormat fmt=new StringFormat(); switch(this.Alignment) { case HorizontalAlignment.Left: fmt.Alignment=StringAlignment.Near; break; case HorizontalAlignment.Right: fmt.Alignment=StringAlignment.Far; break; case HorizontalAlignment.Center: fmt.Alignment=StringAlignment.Center; break; } fmt.FormatFlags=StringFormatFlags.NoWrap; if(rtl) fmt.FormatFlags|=StringFormatFlags.DirectionRightToLeft; gr.FillRectangle(bbbnd); Rectangle rct=new Rectangle(bnd.X+2bnd.Y+3bnd.Width-5bnd.Height); gr.DrawString(txtthis.DataGridTableStyle.DataGrid.Fontfbrctfmt); }