Color
All controls have backcolor and forecolor
Ways to make color:
- ARBG(alpha, red, green, blue) (0-255)
- Predefined .net color name
- Html color name
- OLE color name
- Win32 color code
- Choose name from systemcolors class
Argb Example
Dim alpha as integer=255, red as integer=0
Dim green as integer=255, blue as integer=0
Control.forecolor=color.fromArgb(alpha, red, green, blue)
Color from environment setting:
Control.backcolor=system.color.highlighttext
.net name:
control.backcolor=color.blue
html name:
control.backcolor=colorTranslator.fromHTML(“red”)
Forecolor and backcolor of controls are ambient properties
If not set they inherit from their parent container
Font and cursor are also ambient properties
Alphablending
Alpha is transparency from 0-255
Example (first number in fromARGB is alpha number)
Label1.backcolor=color.fromargb(0,label1,backcolor)
Basic .net controls do not handle transparency well
Fonts and text
Font property determines the Font of a control’s text
Controlname.font=new font(“verdana”,10,fontstyle.bold)
Font family is set with a string
If font is not installed, it reverts to Microsoft’s san serif font
You should check the font first
Example:
- Start a new project
- Add a listbox
- Add this code to the form_load event:
Dim fonts As New System.Drawing.Text.InstalledFontCollection()
For Each fontName As FontFamily In fonts.families
ListBox1.Items.Add(fontName.Name)
Next
AccessKeys
Buttons and menus allow a character in the text to be highlighted as an access key
Placing an ampersand (&) in front of a letter underlines that letter and makes it an access key
The user can press ALT and the key to activate it
Tab Sequence and Focus
One control at a time has the focus
A focused control gets the user’s key presses
A user clicks another control with the mouse or the tab key to move the focus to another control
The tab should move the focus in a predictable way
Most controls have a tabStop property
If true that control can receive the focus
Tabindex property lets you set the tab order
Tabindex of 0 gets the focus first
From the menu select View | tab order
Then you can assign tab order by clicking the controls in order you want them.
Example:
- Start a new project:
- Add 8 button controls
- Mix them up so they tab order is wrong
- Click the View menu and select tab order
- Click them in the order you want them:
- Click View and tab order again to exit it
Hide controls
Set the visible property
Disable a control
Set the enabled property