crystal reports qr code generator Developing a Custom Control in Font

Painting PDF417 in Font Developing a Custom Control

Developing a Custom Control
PDF 417 Creator In None
Using Barcode generator for Font Control to generate, create PDF417 image in Font applications.
www.OnBarcode.com
Barcode Generator In None
Using Barcode creation for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
To make this discussion concrete, consider a control that implements a simple button. You can use the control from C# inside the Visual Studio designer like the native button, as shown in Figure 11-4.
EAN13 Drawer In None
Using Barcode generator for Font Control to generate, create EAN 13 image in Font applications.
www.OnBarcode.com
Making Universal Product Code Version A In None
Using Barcode encoder for Font Control to generate, create GS1 - 12 image in Font applications.
www.OnBarcode.com
Figure 11-4. The F# button control used in a C# application and the Visual Studio designer
Generating Data Matrix ECC200 In None
Using Barcode creation for Font Control to generate, create Data Matrix 2d barcode image in Font applications.
www.OnBarcode.com
Generate PDF-417 2d Barcode In None
Using Barcode printer for Font Control to generate, create PDF 417 image in Font applications.
www.OnBarcode.com
CHAPTER 11 WORKING WITH WINDOWS FORMS AN D C ONTROLS
Code 128 Code Set B Drawer In None
Using Barcode encoder for Font Control to generate, create Code128 image in Font applications.
www.OnBarcode.com
ISSN - 13 Generation In None
Using Barcode creation for Font Control to generate, create ISSN - 13 image in Font applications.
www.OnBarcode.com
You start your control by inheriting from the UserControl class: 2 open open open open System System.Drawing System.Windows.Forms System.ComponentModel
Encode PDF-417 2d Barcode In Visual C#
Using Barcode maker for .NET framework Control to generate, create PDF 417 image in VS .NET applications.
www.OnBarcode.com
PDF417 Drawer In Visual Studio .NET
Using Barcode encoder for Reporting Service Control to generate, create PDF 417 image in Reporting Service applications.
www.OnBarcode.com
type OwnerDrawButton() = inherit UserControl() You then define the state of the control in terms of the fields of the class: let mutable text = "" let mutable pressed = false let fireClick,clickEvent = IEvent.create() The text field will contain the label of the button. As you did for the movingPoint variable in the Curves example, the pressed field is responsible for remembering whether the button is currently pressed, allowing the paint handler to behave appropriately. The fireClick and clickEvent fields remember the listeners registered to be notified of the click event of the button by using the F# events described in 8. You override the OnPaint method to handle the paint event. You allocate the pens and the brush required to draw and invert the role of the border colors in order to achieve the raised effect when the button is not pressed and the depressed look otherwise. You also measure the size of the label string, since you are interested in drawing the string in the center of your button. You can then draw the lines on the borders, playing with colors to obtain a 3D effect. The pens and brushes are disposed at the end of the function. override x.OnPaint (e:PaintEventArgs) = let g = e.Graphics use pll = new Pen(SystemColors.ControlLightLight) use pl = new Pen(SystemColors.ControlLight) use pd = new Pen(SystemColors.ControlDark) use pdd = new Pen(SystemColors.ControlDarkDark) use bfg = new SolidBrush(x.ForeColor) let szf = g.MeasureString(text, x.Font) let spt = PointF((float32(x.Width) - szf.Width) / 2.0f, (float32(x.Height) - szf.Height) / 2.0f) let ptt = if pressed then pdd else pll let pt = if pressed then pd else pl let pb = if pressed then pl else pd let pbb = if pressed then pll else pdd g.Clear(SystemColors.Control) g.DrawLine(ptt, 0, 0, x.Width - 1, 0) g.DrawLine(ptt, 0, 0, 0, x.Height - 1)
Drawing Code 128 In None
Using Barcode creator for Online Control to generate, create Code 128 Code Set B image in Online applications.
www.OnBarcode.com
Paint Barcode In Java
Using Barcode generator for Eclipse BIRT Control to generate, create Barcode image in BIRT applications.
www.OnBarcode.com
2. Note that this example has not been designed to be entered using F# Interactive.
Code-128 Generation In .NET
Using Barcode maker for Reporting Service Control to generate, create Code 128A image in Reporting Service applications.
www.OnBarcode.com
Drawing Barcode In None
Using Barcode creator for Software Control to generate, create Barcode image in Software applications.
www.OnBarcode.com
CHAPTER 11 WORKING WITH WINDOWS FORMS AN D C ONTR OLS
PDF417 Drawer In Java
Using Barcode generator for Java Control to generate, create PDF417 image in Java applications.
www.OnBarcode.com
Make Barcode In Java
Using Barcode maker for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
g.DrawLine(pt, 1, 1, x.Width - 2, 1) g.DrawLine(pt, 1, 1, 1, x.Height - 2) g.DrawLine(pbb, 0, x.Height - 1, x.Width - 1, x.Height - 1) g.DrawLine(pbb, x.Width - 1, 0, x.Width - 1, x.Height - 1) g.DrawLine(pb, 1, x.Height - 2, x.Width - 2, x.Height - 2) g.DrawLine(pb, x.Width - 2, 1, x.Width - 2, x.Height - 2) g.DrawString(text, x.Font, bfg, spt) It is important to note the use of the colors defined in the SystemColors class: you use the system definition of colors so that your button will use the colors set by the user as display settings. Configuration is an important aspect of a user control, since it s normally performed through a visual editor such as Visual Studio. Well-defined controls are those that can be highly customized without having to extend the control programmatically or, even worse, to change its source code. Now that you ve defined the drawing procedure, you can define the behavior of the control by handling mouse events. You restrict the implementation to mouse events, though a key event handler should be provided in order to react to a press of the Enter key. override x.OnMouseUp (e:MouseEventArgs) = pressed <- false x.Invalidate() fireClick() override x.OnMouseDown (e:MouseEventArgs) = pressed <- true x.Invalidate() The OnMouseDown event simply sets the pressed member and asks the control to repaint by invalidating its content. When the mouse is released, the OnMouseUp gets called, and you reset the flag, ask for repaint, and notify the event to registered listeners by using fireClick. Controls are usually configured through the assignment of properties. If you annotate a property with an attribute of type Category, the property will be displayed by Visual Studio in the control property box. To show this, you have defined the Text property that exposes the label of the button to the users of the control. [<Category("Behavior")>] override x.Text with get() = text and set(t:string) = text <- t; x.Invalidate() You re now ready to test your new control by writing a few lines of F# code as follows: let form = new Form(Visible=true) let c = new OwnerDrawButton(Text="Hello button") c.Click.Add(fun _ -> MessageBox.Show("Clicked!") |> ignore) form.Controls.Add(c)
Code 39 Reader In Visual Studio .NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
EAN 13 Decoder In VS .NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
QR Code Scanner In Visual C#
Using Barcode scanner for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Barcode Generator In None
Using Barcode drawer for Word Control to generate, create Barcode image in Microsoft Word applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.