How To Tutorials

How to Create a .NET Button (Program)

1.

To add text to the button, enter the syntax below.

Syntax:

     net_button'text$="Save"

2.

Ensure that the button is enabled.

Syntax:

     net_button'Enabled=1

3.

Ensure that the button is visible.

Syntax:

     net_button'Visible=1

1.

You need to define a Color object to change the appearance of the button.

Syntax:

     def object color,"[.NET]System.Drawing,System.Drawing.Color"

2.

Set BackColor$ for the background color of the button. For this example, the background color will be LemonChiffon.

The PvxHandle$ property is used for assigning or passing in a .NET object to a .NET object constructor, property or method.

Syntax:

     net_button'BackColor$=color'LemonChiffon'pvxhandle$

1.

Define another object called img. This image object (img) will allow the placement of an image.

Syntax:

     def object img,"[.NET]System.Drawing,System.Drawing.Image"

2.

Create a variable to hold the path to the image file using the PTH() function.

For this example, the variable name is image_path$. The path will be dependent on the location of the image you will be using.

Syntax:

     image_path$=pth("*plus\inomads\sysimage\checkmark.png")

3.

The FromFile object will look for the specified image location.

The Image will default to the center of the text. In the next set of steps, you will be changing the alignment.

Syntax:

     net_button'Image$=img'FromFile(image_path$)'pvxhandle$

1.

Define another object called ContentAlignment. This object will allow the alignment of an image. The default is centered.

Syntax:

     def object imgalign,"[.NET]System.Drawing,System.Drawing.ContentAlignment"

2.

For this example, you will be applying a Left alignment. Use the property called MiddleLeft.

Syntax:

     net_button'ImageAlign$=imgalign'MiddleLeft'pvxhandle$

3.

Before going any further, enter START on the Command line to drop all objects.

1.

Copy and paste the following lines of code into a program to be executed.

! dotnet_button - .Net button programmatically
!
! Create and initialize a Button
      def object net_button,@(20,20,18,2.8),"[.NET]System.Windows.Forms,System.Windows.Forms.Button"
!
! Define the object for Color
      def object color,"[.NET]System.Drawing,System.Drawing.Color"
      net_button'BackColor$=color'LemonChiffon'pvxhandle$ ! Set the color of the background
      net_button'ForeColor$= color'FromArgb(220,20,60)'pvxhandle$ ! Add color of the text
!
! Button properties
      net_button'Text$="Save" ! Add text on the button
      net_button'Enabled=1 ! Enable Net_BSave'Enabled=0 ! Disable
      net_button'Visible=1 ! Visible Net_BSave'Visible=0 ! Hide
!
      def object img,"[.NET]System.Drawing,System.Drawing.Image" ! Add an image to the button
      def object imgalign,"[.NET]System.Drawing,System.Drawing.ContentAlignment" ! Align an image
      image_path$=PTH("*plus\inomads\sysimage\checkmark.png")
      net_button'Image$=img'FromFile(image_path$)'pvxhandle$
      net_button'ImageAlign$=imgalign'MiddleLeft'pvxhandle$ ! Re-align to the left of the text
!
  ! Wait for user to click the button
      while 1
      obtain (0,siz=1)'ME',*,'MN'
      if ctl=-1999 \
       then break ! If user closes the dialog using the 'X' top right corner
      wend 
!
! Clean up the object
      drop object color,err=*next
      drop object img,err=*next
      drop object imgalign,err=*next
      drop object Click,err=*next
      drop object net_button,err=*next
!
      end

2.

Save the program as "dotnet_button".

3.

Run the program.

4.

The button will display on the screen. The program will wait for input, at the WHILE/WEND loop, until the dialog is exited via the X (Close button) in the top right corner.

1.

Load the dotnet_button program and insert these lines prior to the WHILE/WEND loop:

Syntax:

     Click=new("ClickEvent")
     on event from Net_Button process Click

2.

Save the program.

3.

Create an object program for the main program to invoke with the lines of code shown below. This program must be called ClickEvent.pvc and be saved in the same directory as the main program.

Insert these lines:

     def class "ClickEvent"
     function Click(sender,evtArgs)Click for event "Click"
     end def
Click:
     enter sender,evtArgs
     msgbox "Information has been updated!","Save Confirmation"
     return

4.

Save and close the program.

5.

To test this event, reload and run the dotnet_button program.

6.

When the button is clicked, the following message box displays: