How do I display a calculated value on a bound column

[Bill Langlais]

Hi,

I have a read-only column which is bound to a field in a DataTable. I want to claculate the displayed value based on the underlying data in the field. Can I do this without having to create another column and hiding the underlying data?

[Administrator]

One way you can do this is to handle the grid.DrawCellDisplayText and there set e.DisplayText to be what you want.

void gridDataBoundGrid1_DrawCellDisplayText(object sender, Syncfusion.Windows.Forms.Grid.GridDrawCellDisplayTextEventArgs e)
{
    if (e.ColIndex == gridDataBoundGrid1.Binder.NameToColIndex("Col2"))
    {
        e.DisplayText = "someComputedTextFrom " + e.Style.Text;
    }
}

[Bill Langlais]

Hi,

I am using a GridGroupingControl and have been unable to find:

gridDataBoundGrid1.Binder.NameToColIndex("Col2")

I have tried the following code:

System::Void
Form1::srgDrawCellDisplayText(System::Object * sender, Syncfusion::Windows::Forms::Grid::Grouping::GridTableControlDrawCellDisplayTextEventArgs * e)
{
if(e->Inner->ColIndex == e->TableControl->Model->NameToColIndex(S"Run Distance")) {
String *Label = String::Format(S"Indexes {0} {1}", __box(e->Inner->RowIndex), __box(e->Inner->ColIndex));
Debug(Label, S"{0} {1}", e->Inner->Style->CellValue, e->Inner->Style->CellType);
// bool IsRecord = Element::IsRecord(e->Inner);
if(e->Inner->Style->CellType == S"TextBox") {
Double x = Convert::ToDouble(e->Inner->Style->CellValue) / 5280;
String *Value = x.ToString(DistFmt);
e->Inner->DisplayText = Value;
Label = String::Format(S"Value {0} {1}", __box(e->Inner->RowIndex), __box(e->Inner->ColIndex));
Debug(Label, S"{0} {1} {2} {3}", e->Inner->Style->CellValue, e->Inner->Style->CellType, Value, e->Inner->Style->ValueMember);
}
}

I find that the Column Index returned by e->TableControl->Model->NameToColIndex(S"Run Distance") does not always come back with the correct index depending on what level I am in in the nested grid. The column name S"Run Distance" exists in several of the nested tables.

Am I using the wrong code to figure out what the right column is for the data column I am trying to modify the display value?

Thanks!

[Administrator]

In the grouping grid, you can cast e.Inner.Style to a GridTableCellStyleInfo object and get the information you need from it. Here is C# code that makes Col1 display 2 times what is in Col2. (Col2 is a column of doubles.)

private void gridGroupingControl1_TableControlDrawCellDisplayText(object sender, GridTableControlDrawCellDisplayTextEventArgs e)
{
	//make Col1 be 2 times the value in Col2
	GridTableCellStyleInfo style = (GridTableCellStyleInfo)e.Inner.Style;
	if(style.TableCellIdentity.Column != null 
		&& style.TableCellIdentity.Column.MappingName == "Col1")
	{
		GridRecord rec = style.TableCellIdentity.DisplayElement.GetRecord() as GridRecord;
		if(rec != null)
		{
			double d = (double) rec.GetValue("Col2");
			e.Inner.DisplayText = string.Format("{0}", 2 * d);
		}
	}
}