Introduction to Application Design

Visual Control Addition

Introduction

To add a control to your application, you can select it from the Toolbox and click the desired area on the form. Once added, the control is positioned where your mouse landed. In the same way, you can add other controls as you judge them necessary for your application. Here is an example of a few controls added to a form:

Alternatively, to add a control, you can also double-click it from the Toolbox and it would be added to the top-left section of the form.

If you want to add a certain control many times, before selecting it on the Toolbox, press and hold Ctrl. Then click it in the Toolbox. This permanently selects the control. Every time you click the form, the control would be added. Once you have added the desired number of this control, on the Toolbox, click the Pointer button to dismiss the control.

1. Start Microsoft Visual C#
2. To create a new application, on the main menu, click File -> New Project...
3. In the Templates list, click Windows Application
4. Set the Name to DesignPractice1 and click OK
5. On the main menu, click View -> Toolbox.
   Position the mouse on the Toolbox word and wait for the Toolbox to expand
6. Click the Label button and position the mouse on the form
    
   
7. Click the form
8. Click the middle of the form to select it (the form)
9. To add another control, position the mouse again on the Toolbox word until the Toolbox has expanded
10. Find and double-click the TextBox button
11. To use a hidden area of the form, position the mouse on the Toolbox word. When the Toolbox has expanded, click the Auto Hide button
12. On the Toolbox, click the TreeView button and click the left section of the form
13. After using the Toolbox, to hide it, click the Auto Hide button
14. To execute the application, on the main menu, click Debug -> Start Without Debugging
15. After using it, close the form and return to your programming environment

We mentioned earlier how you could add a control many times. An alternative is to copy a control. To do this, on the form:

• Right-click the control and click Copy. Right-click another area of the form and click Paste
• Click (once) the control you want to copy
   
  
  
  Press and hold Ctrl. Then drag the selected control to another area of the form. The mouse cursor would display a + plus indicating that the control is being duplicated:
   
  
  
  Once you get to another area of the form, release the mouse and Ctrl

You can use these two techniques to copy a group of controls.

When designing an application, you will manipulate the windows controls on a form. After adding a control to a form, before performing any operation on that control, you must first select it. You can also manipulate many controls at the same time. To do that, you will have to select all those controls.

To select one control on the form, you can simply click it. A control that is selected indicates this by displaying 8 small squares, also called handles, around it. Between these handles, the control is surrounded by dotted rectangles. In the following picture, the selected rectangle displays 8 small squares around its shape:

After selecting a control, you can manipulate it or change its characteristics, also called properties.

To select more than one control on the form, click the first. Press and hold either Shift or Ctrl. Then click each of the desired controls on the form. If you click a control that should not be selected, click it again. After selecting the group of controls, release either Shift or Ctrl that you were holding.

When a group of controls is selected, the last selected control displays 8 square handles around but its handles are white while the others are black. Another technique you can use to select various controls consists of clicking on an unoccupied area on the form, holding the mouse down, drawing a fake rectangle, and releasing the mouse:

Every control touched by the fake rectangle or included in it would be selected:

If there is a control on your form but you don't need it, you can remove it from the application. To delete a control, first select it and then click or press Delete. You can also right-click a control and click Cut. To remove a group of controls, first select them, then click or press Delete or right-click the selection and click Cut.

When adding a control to a form, it assumes a position based on where the mouse landed when you clicked the form. Most of the time, that position will not be convenient. Moving a control consists of specifying its position by changing its previous left and top values. You can do this either graphically or programmatically.

To move a control graphically:

• Position the mouse on it until the cursor changes into a cross:
   
  
  Then click and drag left, right, up or down, until you get to the desired location
• Click the control (once) to select it. Using your keyboard, press either the left, the up, the right, or the down arrow keys to move the control until you get the desired position

You can also move various controls at the same time. To do this, first select the controls:

• Position the mouse on one of the selected controls:
   
  
  
  Then click and drag left, right, up, down, or diagonally, until you get the desired position
• Press the left, the up, the right, or the down arrow keys to move the control until you get the desired position

After adding a control to a form, you can move the control to change its position, as we will learn in the next few sections. In the next lesson, we will learn how you can change the size of a control. The availability of these two operations is controlled by a Boolean property named Locked. The default value of this property is False. Therefore, to prevent the control from being moved or resized, access its Properties window and set the Locked property to True.

Microsoft Visual Studio 2005 provides various tools to assist you with aligning your controls on a form. You can first add a control to a form and position the control the way you want. Here is an example:

Once you have a control on your form, you can add another control as we saw in the previous lesson. To position the other control, you can use the previous one as a reference. To assist you with this, when moving the new control to position it, a guiding vertical line would show you the alignment to follow with regards to an existing control. Here is an example:

Using this approach, once the control is aligned fine, you can release the mouse. As another technique, after positioning one or a few controls, to align a control with reference to another, press and hold Ctrl. Then press the left, the up, the right, or the down arrow key. When you press one of these keys, the control would move to align itself with the next control in that direction. Once the alignment is to your liking, release Ctrl.

There are various other techniques you can use to align the controls. We will review them.

If you have a certain control on the form and want to position it exactly at equal distance between the left and the right borders of the form, select the control, then click the Center Horizontally button on the Layout toolbar :

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Horizontal alignment affects controls whose distance from the left border of the parent must be the same. To perform this type of alignment, the Layout toolbar provides the necessary buttons. The same actions can be performed using menu items of the Format group on the main menu. The options are as follows:

Button	Name	Format Menu	Description
	Align Lefts	Align -> Lefts	All selected controls will have their left border coincide with the left border of the base control
	Align Centers	Align -> Centers	The middle handles of the selected controls will coincide with the middle handles of the base control
	Align Rights	Align -> Rights	All selected controls will have their right border coincide with the right border of the base control

As seen above, the horizontal-oriented buttons allow moving controls left or right. Another option you have consists of moving controls up or down for better alignment. Once again you must first select the controls. Then on the Layout toolbar or the Format group of the main menu, use the following options:

Button	Name	Format Menu	Description
	Align Tops	Align -> Tops	All selected controls will have their top border coincide with the top border of the base control but their left border would have the same distance with the left border of the parent
	Align Middles	Align -> Middles	The top handles of the selected controls will align vertically with the top handle of the base control
	Align Bottoms	Align -> Bottoms	All selected controls will have their bottom border coincide with the bottom border of the base control but their left border would have the same distance with the left border of the parent

Another valuable option you have consists of controlling the alignment of objects with regards to the extreme borders of controls of the selected group.

You can also position one or more controls in the middle of the form. To do that, select the control, then click the Center Vertically button on the Layout toolbar :

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Suppose you have a group of horizontally aligned controls as follows:

Obviously the buttons on this form are not enjoying the most professional alignment. For one thing, the distance between the Continue and the Submit buttons is longer than the distance between the Submit and the Deny buttons. The Layout toolbar and the Format group of the main menu allow you to specify a better horizontal alignment of controls with regards to each other. The options available are:

Button	Name	Format
	Make Horizontal Spacing Equal	Horizontal Spacing -> Make Equal

Result: The Forms Designer will calculate the horizontal distances that separate each combination of two controls and find their average. This average is applied to the horizontal distance of each combination of two controls:

The left control is used as reference

Button	Name	Format
	Increase Horizontal Spacing	Horizontal Spacing -> Increase

Result: The Forms Designer will move each control horizontally, except the base control (the control that has white squares) by one unit away from the base control. This will be done every time you click the Increase Horizontal Spacing button or the Format -> Horizontal Spacing -> Increase menu item:

The left control is used as reference

The middle control is used as reference

The right control is used as reference

Button	Name	Format
	Decrease Horizontal Spacing	Horizontal Spacing -> Decrease

Result: The Forms Designer will move each control horizontally, except the base control (the control that has darker handles) by one unit towards the base control. This will be done every time you click the Decrease Horizontal Spacing button or the Format -> Horizontal Spacing -> Decrease menu item:

The left control is used as reference

The middle control is used as reference

The right control is used as reference

Button	Name	Format
	Remove Horizontal Spacing	Horizontal Spacing -> Remove

Result: The Forms Designer will move all controls (horizontally), except for the left control, to the left so that the left border of a control touches the right border of the next control:

The left control is used as reference

Suppose you have a group of horizontally positioned controls as follows:

The buttons on this form are not professionally aligned with regards to each other. Once again, the Layout toolbar and the Format group of the main menu allow you to specify a better vertical alignment of controls relative to each other. The options available are:

Button	Name	Format
	Make Vertical Spacing Equal	Vertical Spacing -> Make Equal

Result: The Forms Designer will calculate the total vertical distances that separate each combination of two controls and find their average. This average is applied to the vertical distance of each combination of two controls:

The top control is used as reference
	=>

Button	Name	Format
	Increase Vertical Spacing	Vertical Spacing -> Increase

Result: The Forms Designer will move each control vertically, except the base control (the control that has darker handles) by one unit away from the base control. This will be done every time you click the Increase Horizontal Spacing button or the Format -> Horizontal Spacing -> Increase menu item:

The top control is used as reference
	=>
The middle control is used as reference
	=>
The bottom control is used as reference
	=>

Button	Name	Format
	Decrease Vertical Spacing	Vertical Spacing -> Decrease

Result: The Forms Designer will move each control, except the base control (the control that has darker handles) by one unit towards the base control. This will be done every time you click the Decrease Horizontal Spacing button or the Format -> Horizontal Spacing -> Decrease menu item:

The top control is used as reference
	=>
The middle control is used as reference
	=>
The bottom control is used as reference
	=>

Button	Name	Format
	Remove Vertical Spacing	Vertical Spacing -> Remove

Result: The Forms Designer will move all controls vertically, except for the top control, to the top so that the top border of a control touches the bottom border of the next control towards the top:

The top control is used as reference
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