Tutorial 11 - Using Styles to Highlight Related Data

In this tutorial, you will learn how to change the grid's display to highlight rows by creating row styles depending upon a value in the grid. True DBGrid uses the FetchRowStyle event to create style characteristics and apply them to rows dynamically.

1. Start with the project used in Tutorial 10 - Enhancing the User Interface with In-Cell Bitmaps.

2. Add thee buttons to the form. Change the caption of Button1 to Prospective Customers, Button2 to Distributors, and Button3 to Reset the Grid so that the form appears as follows.

3. Add the following declarations to the General section of Form1:

· Visual Basic

Dim bflag As Integer

· C#

int bflag;

· Delphi

var bflag: Integer;

4. Enter the following code in the Click event of Button1:

· Visual Basic

' Prospective Customers.

Me.C1TrueDBGrid1.FetchRowStyles = True

bFlag = 1

Me.C1TrueDBGrid1.Refresh()

· C#

// Prospective Customers.

this.C1TrueDBGrid1.FetchRowStyles = true;

bFlag = 1;

this.C1TrueDBGrid1.Refresh();

· Delphi

// Prospective Customers.

Self.C1TrueDBGrid1.FetchRowStyles := True;

FFlag := 1;

Self.C1TrueDBGrid1.Refresh;

5. Enter the following code in the Click event of Button2:

· Visual Basic

' Distributors.

Me.C1TrueDBGrid1.FetchRowStyles = True

bFlag = 2

Me.C1TrueDBGrid1.Refresh()

· C#

// Distributors.

this.C1TrueDBGrid1.FetchRowStyles = true;

bFlag = 2;

this.C1TrueDBGrid1.Refresh();

· Delphi

// Distributors.

Self.C1TrueDBGrid1.FetchRowStyles := true;

FFlag := 2;

Self.C1TrueDBGrid1.Refresh;

6. Enter the following code in the Click event of Button3:

· Visual Basic

' Reset the grid.

Me.C1TrueDBGrid1.FetchRowStyles = False

Me.C1TrueDBGrid1.Refresh()

· C#

// Reset the grid.

this.C1TrueDBGrid1.FetchRowStyles = false;

this.C1TrueDBGrid1.Refresh();

· Delphi

// Reset the grid.

Self.C1TrueDBGrid1.FetchRowStyles := False;

Self.C1TrueDBGrid1.Refresh;

7. Next enter the following code into the FetchRowStyles event. This code interacts with the setting of the FetchRowStyles property in the click event. When the FetchRowStyles is set to True, the grid fires the FetchRowStyle event when it needs to repaint the cells. Thus the row style is applied according to the value of the bflag flag integer:

· Visual Basic

Private Sub C1TrueDBGrid1_FetchRowStyle(ByVal sender As Object, ByVal e As C1.Win.C1TrueDBGrid.FetchRowStyleEventArgs) Handles C1TrueDBGrid1.FetchRowStyle

If bFlag = 1 And Me.C1TrueDBGrid1 (e.Row,"CustType") = 1 Then

Dim fntFont As New Font(e.CellStyle.Font.Name, e.CellStyle.Font.Size, FontStyle.Bold)

e.CellStyle.Font = fntFont

e.CellStyle.ForeColor = System.Drawing.Color.Blue

End If

If bFlag = 2 And Me.C1TrueDBGrid1 (e.Row, "CustType") = 4 Then

e.CellStyle.ForeColor = System.Drawing.Color.White

e.CellStyle.BackColor = System.Drawing.Color.Red

End If

End Sub

· C#

private void C1TrueDBGrid1_FetchRowStyle( object sender, C1.Win.C1TrueDBGrid.FetchRowStyleEventArgs e)

{

if ( bFlag == 1 && (int)this.C1TrueDBGrid1 [e.Row, "CustType"] == 1 )

{

Font fntFont = new Font(e.CellStyle.Font.Name, e.CellStyle.Font.Size, FontStyle.Bold);

e.CellStyle.Font = fntFont;

e.CellStyle.ForeColor = System.Drawing.Color.Blue;

}

if ( bFlag == 2 && this.C1TrueDBGrid1 [e.Row, "CustType"] == 4 )

{

e.CellStyle.ForeColor = System.Drawing.Color.White;

e.CellStyle.BackColor = System.Drawing.Color.Red;

}

· Delphi

procedure TWinForm.c1TrueDBGrid1_FetchRowStyle(sender: System.Object; e: C1.Win.C1TrueDBGrid.FetchRowStyleEventArgs);

var

MyFont: System.Drawing.Font;

begin

if ((FFlag = 1) and (c1TrueDBGrid1.Columns['CustType'].CellValue(e.Row).ToString = '1')) then

begin

MyFont := System.Drawing.Font.Create(e.CellStyle.Font.Name, e.CellStyle.Font.Size, FontStyle.Bold);

e.CellStyle.Font := MyFont;

e.CellStyle.ForeColor := System.Drawing.Color.Blue;

end

else if ((FFlag = 2) and (c1TrueDBGrid1.Columns['CustType'].CellValue(e.Row).ToString = '4')) then

begin

e.CellStyle.ForeColor := System.Drawing.Color.White;

e.CellStyle.BackColor := System.Drawing.Color.Red;

end;

Run the program and observe the following:

· C1TrueDBGrid1 displays data as in Tutorial 10 - Enhancing the User Interface with In-Cell Bitmaps.

· Click the Prospective Customers button. The grid should appear as follows.

· Click the Distributors button. The grid should now appear as follows:

· Finally, click the Reset the Grid button. The grid should now clear itself of the styles.

This concludes the tutorial.