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CHAPTER 3.1

NOTE

Note that the code in Listing 3.1.3 uses the fully qualified name for the components and methods:

button1.Size = new System.Drawing.Size(408,25);

This longhand form is not always necessary. You could abbreviate the line above to

button1.Size = new Size(408,25);

Layout tools will always give you the longhand version because they never get tired of typing.

Generally, if the object you’re creating is in a namespace you declared you were using, you can use the shorthand.

When you run the file, you will see the application shown in Figure 3.1.2.

3.1

TO NTRODUCTIONI

ORMSF INDOWSW

FIGURE 3.1.2

Using a simple Click Handler.

Defining the Border Style of the Form

The previous examples are both simple, fixed-size forms that have no minimize or restore button. The border style of the form object controls how a form is shown and if it can be resized.

Listing 3.1.4 shows a very simple Windows Forms application with a sizable client area.

LISTING 3.1.4 resize.cs: A Simple Resizable Windows Forms Application

using System;

using System.Drawing;

using System.ComponentModel; using System.WinForms;

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PART III

LISTING 3.1.4 Continued

public class SizeApp : System.WinForms.Form

{

this.Text = “SizeApp”; this.MaximizeBox = true;

this.BorderStyle = FormBorderStyle.Sizable;

}

static void Main()

{

Application.Run(new SizeApp());

}

}

Building and running this application will result in a resizable application that can also be minimized to the taskbar and restored in the normal way.

Adding a Menu

A Windows application without a menu is a rare thing. A Windows Forms application is no exception. Like the button and label you saw earlier, the menu component can be added to

the Menu member of the main application, and events from the menu items can be hooked to handlers.

Menus under .NET come in two forms. MainMenu is applied to a form to provide the main user interface menu, and ContextMenu is used to respond to right mouse clicks. In both cases, the individual items within the menus are objects of type MenuItem. A menu is constructed as a hierarchy of parent and child objects. The main menu owns the individual drop-downs, which in turn own their menu items.

A typical menu creation sequence is seen in Listing 3.1.5.

LISTING 3.1.5 Constructing a Menu

MainMenu menu = new MainMenu();

MenuItem filemenu = new MenuItem(); filemenu.Text = “File”; menu.MenuItems.Add(filemenu);

MenuItem open = new MenuItem(); open.Text = “Open”; filemenu.MenuItems.Add(open);

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PART III

Adding a Menu Shortcut

Placing an ampersand before a character in the menu text will automatically give the menu item an underscore when the Alt key is pressed. The key combination of Alt+F followed by O can be used to invoke the menu handler as if the menu were selected with the mouse.

A direct key combination might also be added to the menu item by using one of the predefined Shortcut enumerations. The File, Open menu item handler can be made to fire in response to a Ctrl+O keypress by adding the shortcut, as shown in Listing 3.1.6.

LISTING 3.1.6 Adding a Shortcut to the File, Open MenuItem

MenuItem filemenu = new MenuItem(); filemenu.Text = “&File”; menu.MenuItems.Add(filemenu);

MenuItem open = new MenuItem(); open.Text = “&Open”; filemenu.MenuItems.Add(open); open.Shortcut = Shortcut.CtrlO; open.ShowShortcut = true;

When you press the Alt key, the F in the File menu is underlined. You can press F to pop up the menu and press O to invoke the menu’s function, as shown in Figure 3.1.4.

FIGURE 3.1.4

Menu shortcuts in action.

Note how the Open menu is appended with the shortcut key press combination Ctrl+O by the

MenuItem.ShowShortcut property setting.