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148 Project 1 CREATING A CUSTOMER MAINTENANCE PROJECT
After you create a Windows application with the name SampleWindowsApplication, Visual Studio .NET creates a solution and a project with the same name. The Windows application opens in the Windows Forms Design view. A default form, Form1, is created for you in the design view. Form1 is an instance of the Form class of the .NET class library and is an interface for your application.
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The Form class lies in the System.Windows.Forms namespace. |
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In addition to creating a default form, Visual Studio .NET creates the default files |
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and references that you require to create your project. Table 8-1 lists some of these |
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files. |
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Table 8-1 The Windows Application Files |
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Files |
Description |
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AssemblyInfo.cs |
The AssemblyInfo.cs file contains assembly information,such as the |
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versions of the assembly. |
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Form.cs |
The Form.cs file contains the code for the default form. |
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References |
The References folder includes references to the namespaces that you |
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use for the de velopment of an application. For example, the References |
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folder contains System, System.Data, System.Drawing, System.Windows.Forms, and System.XML files that contain references to the respective namespaces.
Figure 8-6 displays the default files that are included in the SampleWindowsApplication project.
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FIGURE 8-6 Windows application files
Visual Studio .NET also creates the code for the default form, Form1, which is created in the Windows application. To view the code behind the form, you can either double-click on the form or select the form and press the F7 key. The following sample shows the code that is automatically generated when you create a Windows application.
using System;
using System.Drawing; using System.Collections;
using System.ComponentModel; using System.Windows.Forms; using System.Data;
namespace SampleWindowsApplication
{
public class Form1 : System.Windows.Forms.Form
{
private System.ComponentModel.Container components = null; public Form1()
{
InitializeComponent();
}
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protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code private void InitializeComponent()
{
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); this.ClientSize = new System.Drawing.Size(292, 273); this.Name = “Form1”;
this.Text = “Form1”;
this.Load += new System.EventHandler(this.Form1_Load);
}
#endregion
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void Form1_Load(object sender, System.EventArgs e)
{
--------
}
}
}
When you create a Windows application in Visual Studio .NET, a default namespace with the same name as that of your application is also created. In this case,
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a default namespace is created with the name SampleWindowsApplication. In addition, Visual Studio .NET includes some of the existing namespaces in the appli-
cation, such as System, System.Drawing, System.Collections, and so on. Inside the
SampleWindowsApplication namespace, a public class named Form1 is created. When you add controls to the form, the declarations of the controls are added to this class. You will learn to add controls to a form later in this chapter.
The Form1 class contains a default constructor named Form1. The constructor includes the InitializeComponent() method. This method contains the statements required to initialize the Windows form used in the application. For example, the InitializeComponent() method includes the name of the form. The declaration for the InitializeComponent() method is included in the #region preprocessor directive.
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#region preprocessor directives are used to demarcate regions.
In addition, the Form1 class contains the Dispose() method, which is called to deallocate the memory occupied by the components that are no longer used by the application.The class also includes the Main() method, which is the starting point of the execution of the program. Finally, the public class includes the declaration of the Form1_Load method, which is used in the InitializeComponent() method.
This previous code creates a blank form for your application to which you need to add functionality through various controls.The following section discusses how to add controls to your form.
Adding Controls to a Windows Form
Visual Studio .NET provides you with various Windows form controls that you can add to your application by just dragging the controls to your form. Figure 8-7 displays the Windows form controls available with Visual Studio .NET.
152 Project 1 CREATING A CUSTOMER MAINTENANCE PROJECT
FIGURE 8-7 Windows form controls available with Visual Studio .NET
You will now add a button to SampleWindowsApplication. To add a button, drag a Button control to the form. You can place the Button control anywhere in the form. Figure 8-8 shows a Windows form with a Button control.
FIGURE 8-8 Windows form with a Button control
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As discussed earlier, when you add a control to the form, the declaration of the control is added to the Form1 class. The following code shows the declaration of the Button control:
private System.Windows.Forms.Button button1;
As you can see, the button has the text button1 on it. To change the text displayed on the button, you must change its properties.
Changing the Properties of a Windows Form Control
You can view the properties of a button in the Properties window. Figure 8-9 displays the Properties window.
FIGURE 8-9 The Properties window
To change the properties of the button, perform the following steps:
1.Select the button to make it active.
2.In the Properties window, make the following changes to the properties of a button:
Text: Welcome
Name: sampleButton
154 Project 1 CREATING A CUSTOMER MAINTENANCE PROJECT
Font:
Name: Arial
Your button now displays the text Welcome. The button that you created, however, does not perform any action. To add some functionality to the button, you need to add code to button1_Click() method. You can add code to display a message box when the button is clicked.
private void button1_Click(object sender, System.EventArgs e)
{
MessageBox.Show(“This is a sample Windows Application”);
}
The sample Windows application that you created in the preceding code is shown in Figure 8-10.
FIGURE 8-10 Sample Windows application
In addition to the Button control, you can create other controls in a Windows application.The following section discusses some of these controls.
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Types of Windows Forms Controls
Windows forms controls are used with Windows forms to accept user input. In addition to using Windows controls that are provided by Visual Studio .NET, you can create custom controls. In this section, you will look at some of the controls provided by Visual Studio .NET.
Button Control
A Button control is used to allow a user to perform a specified action on the click of a mouse. You can specify the action to be performed in the click event of the button. The following steps will create a Button control in a Windows form, Form1, which displays another form, Form2, when the button is clicked. In addition, Form1 is hidden when the button is pressed. To create the Button control, perform the following steps:
1.Drag a Button control from the Windows Forms toolbox to Form1.
2.Change the following properties of the Button control:
Name: btnShow
Text: &Show
3.Double-click on the Button control to display the code.
4.Add the following code to the Click event of the control:
private void button1_Click(object sender, System.EventArgs e)
{
Form2 newForm = new Form2(); newForm.Show();
this.Hide();
}
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If you prefix a letter in the Text property of a Button control with an ampersand (&), Visual Studio .NET creates the letter as the access key for the Button control. You can then access the button by using the Alt key in combination with the access key. For example, prefixing an ampersand with the letter S in the text property of the Show button allows you to click the Show button by using Alt and S keys.
156 Project 1 CREATING A CUSTOMER MAINTENANCE PROJECT
Label Control
A Label control is used to display static text or images. You can use a Label control to display the descriptions of controls used in a form. For example, you can create a Label control to specify the description of the Button control that you created in the previous example. To create the Label control, perform the following steps:
1.Drag a Label control from the Windows Forms toolbox to Form1.
2.Change the following properties of the Label control.
Name: lblDescription
Text: Click on the Show button to display Form 2
Font:
Name: Arial
Size: 10
Bold: True
Figure 8-11 shows Form1.
FIGURE 8-11 Form1
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TextBox Control
A TextBox control is used to allow a user to input values to a form. You can also use a TextBox control to display dynamic text. This implies that you can change the value in the text box at run time.
MainMenu Control
A MainMenu control is used to create menu items in a form. You can drag the MainMenu control to the form to create menu items at run time. You can use the Checked property of the MainMenu control to find whether the control is selected or not. The following steps show you how to create the File menu for Form1.
1.Drag a MainMenu control from the Windows Forms toolbox to the form.
A menu item is added to the form.
2.Click on the text Type Here and type the name of the first menu item as
&File.
3.In the text area below the File menu, type &New to create the New option.
Similarly, you can create the Open, Save, Save As, and Exit options.
4.To add a menu item adjacent to the File option, type &Edit in the text area to the right of the File menu.
Similarly, you can create Cut, Copy, and Paste options on the Edit menu.
However, the menu items that you have created so far do not perform any function. To add functionality to the menu item, you need to add code to the click event of the menu option.
5.Double-click the New option to display the code window.
6.Type the following code in the click event of the New option.
private void menuItem2_Click_1(object sender, System.EventArgs e)
{
Form2 newForm = new Form2(); newForm.Show();
this.Hide();
}