For cases where regular expressions are insufficient to express formatting requirements, use the FetchCellStyle event to customize fonts and colors on a per-cell basis. This event will only be fired for columns that have the FetchStyle property set to True.
For example, provide color coding for values that fall within a certain range. The following code assumes that the FetchStyle property is True for a single column of numeric data, and handles the FetchCellStyle event to display values greater than 1000 in blue:
Private Sub C1TrueDBGrid1_FetchCellStyle(ByVal sender As Object, ByVal e As C1.Win.C1TrueDBGrid.FetchCellStyleEventArgs) Handles C1TrueDBGrid1.FetchCellSTyle
Dim N As Integer
N = Val(Me.C1TrueDBGrid1(e.Row, e.Col)
If N > 1000 Then
e.CellStyle.ForeColor = System.Drawing.Color.Blue
End If
End Sub
· C#
private void C1TrueDBGrid1_FetchCellStyle( object sender, C1.Win.C1TrueDBGrid.FetchCellStyleEventArgs e)
{
int N;
N = (int) this.C1TrueDBGrid1[e.Row, e.Col];
if ( N > 1000 )
{
e.CellStyle.ForeColor = System.Drawing.Color.Blue;
}
}
· Delphi
procedure TWinForm.C1TrueDBGrid1_FetchCellStyle(sender: System.Object, e: C1.Win.C1TrueDBGrid.FetchCellStyleEventArgs);
var
N: Integer;
begin
N := Int32.Parse(Self.C1TrueDBGrid1.Columns[e.Col].CellText(e.Row));
if N > 1000 then
e.CellStyle.ForeColor := System.Drawing.Color.Blue;
end;
The Split, Row, and Col properties identify which cell the grid is displaying. The CellStyle property conveys formatting information from the application to the grid. Since the CellStyle property is a Style object, a cell's font characteristics can also be changed in the FetchCellStyle event:
If N > 1000 Then
e.CellStyle.Font.Italic = True
Dim myfont As Font
myfont = New Font (e.CellStyle.Font, FontStyle.Italic)
If N > 1000 Then
e.CellStyle.Font = myfont
· C#
if ( N > 1000 )
{
e.CellStyle.Font.Italic = true
}
Font myfont;
myfont = new Font (e.CellStyle.Font, FontStyle.Italic);
if ( N > 1000 )
{
e.CellStyle.Font = myfont;
}
· Delphi
If N > 1000 Then
e.CellStyle.Font.Italic := True;
var myfont: Font;
myfont := Font.Create(e.CellStyle.Font, FontStyle.Italic);
if N > 1000 then
e.CellStyle.Font := myfont;
The FetchCellStyle event can also be used to apply formatting to one cell based upon the values of other cells, or even other controls. For example, suppose that you want to:
· Make the cell text red in column 4 if column 1 minus column 2 is negative.
· Make the cell text bold in column 7 if it matches the contents of a text box.
In this case, set the FetchStyle property to True for columns 4 and 7, and handle the FetchCellStyle event as follows:
Private Sub C1TrueDBGrid1_FetchCellStyle(ByVal sender As Object, ByVal e As C1.Win.C1TrueDBGrid.FetchCellStyleEventArgs) Handles C1TrueDBGrid1.FetchCellStyle
Select Case e.Col
Case 4
Dim Col1 As Long, Col2 As Long
Col1 = CLng(Me.C1TrueDBGrid1(e.Row, 1))
Col2 = CLng(Me.C1TrueDBGrid1(e.Row, 2))
If Col1 - Col2 < 0 Then
CellStyle.ForeColor = System.Drawing.Color.Red
Case 7
Dim S As String
S = Me.C1TrueDBGrid1(e.Row, 7).ToString()
If S = TextBox1.Text Then
Dim myfont = New Font(CellStyle.Font, FontStyle.Bold)
CellStyle.Font = myfont
End If
Case Else
Debug.WriteLine ("FetchCellStyle not handled: " & e.Col)
End Select
End Sub
· C#
private void C1TrueDBGrid1_FetchCellStyle( object sender, C1.Win.C1TrueDBGrid.FetchCellStyleEventArgs e)
{
switch (e.Col)
{
case 4:
long Col1, long Col2;
Col1 = (long)this.C1TrueDBGrid1[e.Row, 1];
Col2 = (long)this.C1TrueDBGrid1[e.Row, 2];
if ( Col1 - Col2 < 0 )
CellStyle.ForeColor = System.Drawing.Color.Red
break;
case 7:
string S;
S = this.C1TrueDBGrid1[e.Row, 7].ToString();
if ( S == TextBox1.Text )
{
Font myfont = new Font(CellStyle.Font, FontStyle.Bold);
CellStyle.Font = myfont;
}
break;
default:
Console.WriteLine ("FetchCellStyle not handled: " + e.Col);
}
}
· Delphi
procedure TWinForm.C1TrueDBGrid1_FetchCellStyle(sender: System.Object; e: C1.Win.C1TrueDBGrid.FetchCellStyleEventArgs);
var
Col1, Col2: LongInt;
S: String;
begin
case e.Col of
4: begin
Col1 := LongInt(Self.C1TrueDBGrid1.Columns[1].CellText(e.Row));
Col2 := LongInt(Self.C1TrueDBGrid1.Columns[2].CellText(e.Row));
if Col1 - Col2 < 0 then
CellStyle.ForeColor := System.Drawing.Color.Red;
end;
7: begin
S := Self.C1TrueDBGrid1.Columns[7].CellText(e.Row);
if S := TextBox1.Text then
begin
Dim myfont := New Font(CellStyle.Font, FontStyle.Bold);
CellStyle.Font := myfont;
end;
end
else
Debug.WriteLine ('FetchCellStyle not handled: ');
end;
end;
For efficiency reasons, only set FetchStyle to True for columns that you plan to handle in the FetchCellStyle event.
Note: The preceding examples use the CellText method for simplicity. However, the CellText and CellValue methods always create and destroy an internal clone of the dataset each time they are called, which may make them too inefficient to use in the FetchCellStyle event. To improve the performance of the grid's display cycle, try an unbound application. Unbound applications can access the underlying data source directly, which is generally faster than calling CellText or CellValue.
To customize fonts and colors on a per-row instead of a per-cell basis, use the FetchRowStyle event, which will only be fired once per row for grids that have the FetchRowStyles property set to True. The syntax for this event is as follows:
Private Sub TDBGrid1_FetchRowStyle(ByVal sender As Object, ByVal e As C1.Win.C1TrueDBGrid.FetchRowStyleEventArgs) Handles C1TrueDBGrid1.FetchRowStyle
· C#
private void TDBGrid1_FetchRowStyle( object sender, C1.Win.C1TrueDBGrid.FetchRowStyleEventArgs e)
· Delphi
procedure TDBGrid1_FetchRowStyle(sender: System.Object; e: C1.Win.C1TrueDBGrid.FetchRowStyleEventArgs);
Although the FetchRowStyle event can be used to implement an alternating row color scheme, an easier and more efficient way to accomplish the same task would be to use the AlternatingRows property, together with the built-in EvenRow and OddRow styles.
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