More Control Properties Part 10 dbg

Form Properties that Affect TitleBar ControlBox Property (T/F) Do you display the icon, associated menu to the left, and buttons to right of the Text Property of form? Yes allows keyboard access (Alt + spacebar) to close, move, resize, minimize, maximize, restore. Icon Property (.ico file) Substitute a particular.ico graphic file as the ControlBox icon.  Icon

Form Properties that Affect TitleBar MaximizeBox Property (T/F) determines whether or not the form can be maximized. MaximizeButton is dimmed when false. MinimizeBox Property(T/F) detemines whether or not the form can be minimized. MinimizeButton is dimmed when false.  ControlBox

More Form Properties MinimumSize (Width in pixels, Height in pixels) --- This is the smallest possible size of form. ShowInTaskBar (T/F) --- Do you want this form to display a taskbar button, listing this form as a “running application”? WindowState (Normal, Minimized, Maximized) --- Should this form should have its normal size, be minimized at startup, or be maximized at startup?  TaskBarItem

Position of Controls when Form is Resized When a user resizes a form by dragging the border or SizeGrip, form controls will “float” to new positions on form. To control this “floating”, set Anchor Property (top, left, bottom, right). This keeps control in same place relative to anchored side(s). You may select multiple sides to anchor to. When form is resized, control will stay the original (design) distance from specified side(s).

Position of Controls when Form is Resized Dock Property (top, left, bottom, right, none). This causes the size of control to expand or contract to match the size of docked side. Dock Padding Property (pixels). This distance between control and docked side will not change as form is resized.  Dock

Different Looks for RadioButtons and CheckBoxes You can alter the look of a traditional CheckBox by setting the Appearance Property to Button. Toggling the “Button” will alter the Checked Property of the CheckBox. You can alter the appearance of a RadioButton by setting the Appearance Property to Button. Clicking a “Button” will alter the Checked Property of the RadioButton. The Image and BackColor properties can be adjusted, for effect, if desired.  ToggleCheck  ToggleRadio

TrackBar and ScrollBar Controls Filled with a Number Series

TrackBar Properties A TrackBar is a control that can conveniently display a range of values. How far apart the Ticks appear is set in the TickFrequency Property. The look of the Thumb and Ticks is set in the TickStyle Property. Set lowest value for TrackBar in Minimum Property. Set highest value for TrackBar in Maximum Property. Starting Value of the Thumb is set in the Value Property.

User Interaction with TrackBar The user drags the Thumb to change the TrackBar Value Property. The minimal amount the Value Property can change is determined by the SmallChange Property. The user can also click on the TrackBar. Clicking to left of Thumb decreases the TrackBar Value Property by the LargeChange Property amount. Clicking to the right of Thumb increases TrackBar Value Property by the LargeChange Property amount.

TrackBar When the Value Property of the TrackBar is changed, the Scroll event “fires”. The TrackBar control does not display the actual value chosen. Good design dictates that the Value be displayed in a Label control. Use the prefix tkb with the TrackBar.  NormalTrackBar

Unusual TrackBars Normally the values of a TrackBar are increasing left to right. However, you may have a TrackBar with values decreasing from left to right by setting the RightToLeft Property to Yes. Whether the TrackBar is vertical or horizontal is set in the Orientation Property. To produce a regular series of non- contiguous values, multiply or divide the Value Property, as necessary.  NoncontiguousTrackBar  TrackBar2

The Resize Event Handler The previous example stops working correctly if the form is resized. Program the Resize event handler of the form to update the Maximum Properties of the TrackBar controls with the new ClientSize dimensions.  Resize

ScrollBar There are two separate ScrollBar controls for vertical (vsb prefix) and horizontal (hsb prefix) orientations. The Thumb of the ScrollBar control is a box rather than a pointer. There are no Ticks. The SmallChange Property controls the change produced by clicking on the end arrows of the control. Usage is otherwise similar to the TrackBar.  ScrollBars

Random Numbers

Random The Random object has a pair of methods for generating either random integers or random doubles. For small ranges of values, instantiating a Random object is adequate to generate unique sequences of numbers. For larger random numbers (3, 4, 5, 6, 7 etc digits), it may be necessary to seed the Random object with a value derived from the system clock to insure that a pseudorandom sequence is unique; do this at instantiation.

Next() Method The Next() method of the Random object delivers a random integer. The method is overloaded and can accept 0, 1 or 2 arguments. With no arguments, integers between 0 and 2,147,483,647 are delivered. Random.Next();

Next() Method With a single argument, integers between 0 and argument -1 are delivered. Random.Next(6); //delivers integers in the range 0 to 5 With two arguments, integers between argument1 and argument2 -1 are delivered. Random.Next(2,8); //delivers integers in the range 2 to 7  IfElseRandom  SwitchRandom  RandomInteger

NextDouble() Method NextDouble() does not take arguments. Values produced are greater than or equal to 0.0 and less than 1.0. To obtain double precision values in some other range, multiply the random double by some upper limit value. To adjust the lower limit, subtract the lower limit from the upper limit multiplier and then add the lower limit to the product of the random double and the multiplier.  RandomDoubles