Changing the Appearance of a Form

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Take a moment to browse the rest of the form's properties in the Properties window. In this hour , I'll show you how to use the more common properties of the form to tailor its appearance.

Remember, to get help on any property at any time, select the property in the Properties window and press F1.

Displaying Text on a Form's Title Bar

You should always set the text in a form's title bar to something meaningful. (Note: Not all forms have title bars, as you'll see later in this hour.) The text displayed in the title bar is the value placed in the form's Text property. Generally , the text should be one of the following:

• The name of the program. This is most appropriate when the form is the program's main or only form.

• The purpose of the form. This is perhaps the most common type of text displayed in a title bar. For example, if a form is used to select a printer, consider setting the Text property to Select Printer. When you take this approach, use active voice (for instance, don't use Printer Select).

• The name of the form. If you choose to place the name of the form into the form's title bar, use the "English" name, not the actual form name. For instance, if you've used a naming convention and named a form fclsLogin, use the text Login or Login Form.

Change the Text property of your form to Building Forms Example. Your form should now look like the one in Figure 5.1.

Figure 5.1. Use common sense when setting title bar text.

As with most other form properties, you can change the Text property at any time using C# code.

Changing a Form's Background Color

Although most forms appear with a gray background (this is part of the standard 3D color scheme in Windows ), you can change a form's background to any color you like. To change a form's background color, you change its BackColor property. The BackColor property is a unique property in that you can specify a named color or an RGB value in the format Red, Green, Blue.

By default, the BackColor is set to the color named Control. This color is a system color and may not be gray. When Windows is first installed, it's configured to a default color scheme. In the default scheme, the color for forms and other objects is the familiar "battleship" gray. However, as a Windows user , you're free to change any system color you desire . For instance, some people with color blindness prefer to change their system colors to colors that have more contrast than the defaults so that objects are more clearly distinguishable . When you assign a system color to a form or control, the appearance of the object adjusts itself to the current user's system color scheme. This doesn't just occur when a form is first displayed; changes to the system color scheme are immediately propagated to all objects that use the affected colors.

Change the background color of your form to blue now by deleting the word Control in the BackColor property in the Properties window; in its place enter 0,0,255 and press Enter or Tab to commit your entry. Your form should now be blue because you entered an RGB value in which you specified no red, no green, and maximum blue (color values range from 0 to 255). In reality, you'll probably rarely enter RGB values. Instead, you'll select colors from color palettes. To view color palettes from which you can select a color for the BackColor property, click the drop-down arrow in the BackColor property in the Properties window (see Figure 5.2).

Figure 5.2. All color properties have palettes from which you can choose a color.

System colors are discussed in detail in Hour 10, "Drawing and Printing."

When the drop-down list appears, the color Blue on the Web tab is selected. This occurs because when you entered the RGB value 0,0,255, C# looked for a named color composed of the same values and it found blue. The color palettes were explained in Hour 2, "Navigating C#," so I'm not going to go into detail about them here. For now, select the System tab to see a list of the available system colors and choose Control from the list to change the BackColor of your form back to the default Windows color.

Adding an Image to a Form's Background

In addition to changing the color of a form's background, you can also place a picture on it. To add a picture to a form, set the form's BackgroundImage property. When you add an image to a form, the image is " painted " on the form's background. All the controls that you place on the form appear on top of the picture.

Add an image to your form now by following these steps:

1. Select the form.

2. Click the BackgroundImage property in the Properties window.

3. Click the Build button that appears next to the property (the small button with three dots).

4. Use the Open dialog box that appears to locate and select an image file from your hard drive. (I used Blue Lace 16.BMP, which I found in my \WinNT folder.)

C# always tiles an image specified in a BackgroundImage property (see Figure 5.3). This means that if the selected picture isn't big enough to fill the form, C# will display additional copies of the picture, creating a tiled effect. If you want to display a single copy of an image on a form, anywhere on the form, you should use a picture box, as discussed in Hour 10.

Figure 5.3. Images are tiled to fill the form.

Notice that to the left of the BackgroundImage property is a small box containing a plus sign. This indicates that there are related properties, or subproperties , of the BackgroundImage property. Click the plus sign now to expand the list of subproperties (see Figure 5.3). In the case of the BackgroundImage property, C# shows you a number of properties related to the image assigned to the property, such as its dimensions and image format.

Adding background images to forms can add pizzazz to a program, but it can also confuse users by making forms unnecessarily busy. Try to avoid adding images just because you can. Use discretion, and add an image to a form only when the image adds value to the interface.

Removing an image from a form is just as easy as adding the image in the first place. To remove the picture that you just added to your form, right-click the BackgroundImage property name and choose Reset from the shortcut menu that appears.

You must right-click the Name column of the property, not the Value column. If you right-click the value of the property, you get a different shortcut menu that doesn't have a Reset option.

Giving a Form an Icon

The icon assigned to a form appears in the left side of the form's title bar, in the taskbar when the form is minimized, and in the iconic list of tasks when you press Alt+Tab to switch to another application. The icon often represents the application; therefore, you should assign an icon to any form a user can minimize. If you don't assign an icon to a form, C# supplies a default icon to represent it when the form is minimized. This default icon is generic and unattractive, and you should avoid it.

In the past, it was recommended that every form have a unique icon related to the form's purpose. This has proved very difficult to accomplish in large applications. As an alternative, I recommend that you set the icon of the main form in your program to the icon that you want to represent your application, and then assign that icon to other forms as they are loaded rather than assigning them at design time. If this proves to be a hassle, just assign the same icon to all your forms.

You assign an icon to a form in much the same way you assign an image to the BackgroundImage property. Add an icon to your form now by clicking the form's Icon property in the Properties window, clicking the Build button that appears, and selecting an icon file from your hard drive. After you've selected the icon, it appears in the form's title bar to the left.

Run your project by pressing F5, and then click the form's Minimize button to minimize it to the taskbar. Look at the form in the taskbar; you'll see both the form's caption and the form's icon displayed (see Figure 5.4).

Figure 5.4. Assigning meaningful icons to your forms makes your application easier to use.

Stop the project now by choosing Stop Debugging from the Debug menu.

Preventing a Form from Appearing in the Taskbar

Being able to display an icon for a minimized form is nice, but sometimes it's necessary to prevent a form from even appearing in the taskbar. For instance, if your application has a number of palette windows that float over a main form, it's unlikely that you'd want all but your main form to appear in the taskbar. To prevent a form from appearing in the taskbar, set the form's ShowInTaskbar property to false. If the user minimizes a form with its ShowInTaskbar property set to false, the user can still get to the application by pressing Alt+Tab, even though the program can't be accessed via the taskbar; C# won't allow the application to become completely inaccessible to the user.

Changing the Appearance and Behavior of a Form's Border

You may have noticed while working with other Windows programs that the borders of forms can vary. Some forms have borders that you can click and drag to change the size of the form, some have fixed borders that can't be changed, and still others have no borders at all. The appearance and behavior of a form's border is controlled by its FormBorderStyle property.

The FormBorderStyle property can be set to one of the following values:

• None

• FixedSingle

• Fixed3D

• FixedDialog

• Sizable

• FixedToolWindow

• SizableToolWindow

Run your project now by pressing F5, and move the mouse pointer over one of the borders of your form. This form has a sizable border, which means that the border can be resized by the user. Notice how the pointer changes from a large arrow to a line with arrows pointing on either side, indicating the direction you can stretch the border. When you move the pointer over a corner, you get a diagonal cursor that indicates you can stretch both of the sides that meet at the corner.

Stop the project now by choosing Stop Debugging from the Debug menu (or click the Close button on the form) and change the form's FormBorderStyle property to None. Your form should look like the one in Figure 5.5. When you choose to not give a form a border, the title bar of the form is removed. Of course, when the title bar is gone, there is no visible title bar text, no control box, and no Minimize or Maximize buttons . Run your project by pressing F5, and notice how the form appears as it did in Form Design viewwith no border or title bar. Without a border, the form cannot be resized by the user, and without a title bar, the form cannot be repositioned. Rarely is it appropriate to specify None for a form's BorderStyle, but in the event you need to do this, it's entirely possible.

Figure 5.5. You can create forms without borders.

Stop the project (you should know how by now) and change the FormBorderStyle to FixedDialog. Press F5 to run the project again, and move the mouse pointer over a border of the form; the mouse pointer won't change, and you won't be able to stretch the borders of the form. Stop the project again and set the form's FormBorderStyle property to FixedToolWindow. This setting causes the title bar of the form to appear smaller than normal and the text to display in a smaller font (see Figure 5.6). In addition, the only thing displayed on the title bar besides the text is a Close button. C#'s various design windows, such as the Properties window and the toolbox, are good examples of tool windows.

Figure 5.6. A tool window is a special window whose title bar takes up the minimum space possible.

The FormBorderStyle is a good example of how changing a single property can greatly affect the look and behavior of an object. Set the FormBorderStyle of the form back to Sizable, the default setting for new forms.

Adding Minimize, Maximize, and Control Box Buttons to a Form

Minimize and Maximize buttons make it easy for a user to quickly hide a form or make it fill the entire display. Adding a Minimize or Maximize button to your forms is as easy as setting a property (or two). To add a Minimize button to a form's title bar, set the form's MinimizeBox property to true. To add a Maximize button to a form, set its MaximizeBox property to true. Conversely, set the appropriate property to false to hide a button.

The form's ControlBox property must be set to true to display a Maximize and/or Minimize button on a form. When the ControlBox property of a form is set to true, a button with an X appears in the title bar at the right side, which the user can click to close the form. In addition, the form's icon is displayed in the left side of the title bar, and clicking it opens the form's System menu.

Notice that the title bar of your form shows all three buttons to the far right. From left to right, these are Minimize, Maximize, and Close. Run the project now and right-click the title bar to open the control box's menu, as shown in Figure 5.7. Notice that the icon isn't visible in the form's title bar. Some FormBorderStyle settings cause the icon to be hidden. When this occurs, right-clicking the title bar causes the menu to appear as though you clicked the icon. Close the form now by either selecting Close from the menu or clicking the Close button on the far right of the title bar.

Figure 5.7. Clicking the icon of a form with a control box (or right-clicking a title bar) displays a system menu.

Changing the MaximizeBox or MinimizeBox properties of a form enables or disables the corresponding item on the system menu in addition to the button on the toolbar. Save your project now by clicking the Save All button on the toolbar.

Specifying the Initial Display Position of a Form

The location on the display (monitor) where a form first appears isn't random but is controlled by the form's StartPosition property. The StartPosition property can be set to one of the values in Table 5.1.

Table 5.1. Values for the StartPosition Property

Value	Description
Manual	The Location property of the form determines where the form first appears.
CenterScreen	The form appears centered in the display.
WindowsDefaultLocation	The form appears in the Windows default location, which is toward the upper left of the display.
WindowsDefaultBounds	The form appears in the Windows default location with its bounds (size) set to the Windows default bounds.
CenterParent	The form is centered within the bounds of its parent form.

Generally, it's best to set the StartPosition property of all your forms to CenterParent, unless you have a specific reason to do otherwise . For the very first form that appears in you project, you might consider using the WindowsDefaultLocation (but I generally prefer CenterScreen).

Displaying a Form in a Normal, Maximized, or Minimized State

Using the Size and Location properties of a form in conjunction with the StartPosition property enables you to display forms at any location and at any size. You can also force a form to appear minimized or maximized. Whether a form is maximized, minimized, or shown normally is known as the form's state, and it's determined by the WindowState property.

Look at your form's WindowState property now. New forms have their WindowState property set to Normal by default. When you run the project, as you have several times, the form displays in the same size as it appears in the form designer, at the location specified by the form's Location property. Change the WindowState property now to Minimized. Nothing happens in the Form Design view, but run your project by pressing F5 and you'll see that the form is immediately minimized to the taskbar.

Stop the project and change the WindowState property to Maximized. Again, nothing happens in the Form Design window. Press F5 to run the project and notice how the form immediately maximizes to fill the entire screen.

When a form is maximized, it fills the entire screen regardless of the current screen resolution being used in Windows.

Stop the project and change the WindowState property back to Normal. Rarely will you set a form's WindowState property at design time to Minimize, but you'll probably encounter situations in which you need to change (or determine) the WindowState at runtime. As with most properties, you can accomplish this using code. For example, the following statement would minimize a form: this.WindowState = FormWindowState. Minimized . You don't have to remember the names of the values when entering code; you'll get an IntelliSense drop-down list when you type the period.

Changing the Mouse Pointer

You've no doubt used a program that altered the cursor when the pointer was moved over an object. This behavior is prevalent in Web browsers, in which the cursor is changed to the shape of a pointing hand when moved over a hyperlink. Using the Cursor property, you can specify the image of the pointer displayed when the pointer is over a form (or control).

Click the Cursor property of the form in the Properties window now and a drop-down arrow appears. Click the arrow to view a list of cursors (see Figure 5.8). Selecting a cursor from the list causes the pointer to change to that cursor when positioned over the form. Change the Cursor property of the form to AppStarting and press F5 to run the project. Move the pointer over the form and notice that the cursor changes to the AppStarting cursor while over the form and reverts to the default cursor when moved off the form. Stop the project now and click Save All on the toolbar to save your work.

Figure 5.8. Use the Cursor property to designate the image of the pointer when it's moved over the object.

Rarely will you want to change the cursor for a form, but you may find occasion to change the Cursor property for specific controls. Whenever you find yourself changing the default cursor for a form or control, choose a cursor that is consistent in purpose with well-known commercial applications.

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