实例说明
在本实例中将自行制作一个用户自定义控件并在另外的一个应用程序中加以引用。程序运行后，可以更改其中的内容，然后单击save即可。程序运行结果如图58-1所示。
图58-1 运行结果
技术要点
l 定制用户控件界面
l 编译用户控件
l 引用用户控件
实现过程
■ 新建项目
打开Visual Studio.NET，选择"新建项目"，在项目类型窗口中选择"Visual Basic项目"，在模板窗口中选择"Windows控件库"，在名称域中输入"CustomControl"，然后选择保存路径。单击"确认"。
■ 添加控件
向当前用户控件UserControl1上添加五个Label控件和五个TexbBox控件。
■ 设置属性
对用户控件UserControl1上的控件设置属性，如表58-1所示。
表58-1 各控件的属性值
窗体/控件 属性 值
UserControl BackColor &H00C00000
Text5 Text
ScrollBars 2-Vertical
MultiLine True
Label1 Text ID
Text1 Text
其余Label、TextBox控件 Text 跟界面一致
■ 添加组件类
通过菜单"项目|添加新项"，在弹出的对话框中选择"组件类"，在名称栏中输入Customer，单击"确定"。
Imports System
Imports System.Windows.Forms
Imports System.Drawing
Namespace Microsoft.Samples.WinForms.VB.CustomerControl
Public Class CustomerControl
Inherits System.Windows.Forms.UserControl
Private customer1 As Customer
Public Sub New()
MyBase.New()
' required by the Windows Forms Designer
InitializeComponent()
' TODO: Add any constructor code after InitializeComponent call
End Sub
Public Property Customer() As Customer
Get
Return customer1
End Get
Set(ByVal Value As Customer)
customer1 = Value
LoadCustomer()
End Set
End Property
Public Sub AcceptChanges()
customer1.Title = textBoxTitle.Text
customer1.FirstName = textBoxFirstName.Text
customer1.LastName = textBoxLastName.Text
customer1.Address = textBoxAddress.Text
End Sub
Public Sub RejectChanges()
LoadCustomer()
End Sub
Private Sub LoadCustomer()
textBoxID.Text = customer1.ID
textBoxTitle.Text = customer1.Title
textBoxFirstName.Text = customer1.FirstName
textBoxLastName.Text = customer1.LastName
textBoxAddress.Text = customer1.Address
End Sub
Public Overloads Overrides Sub Dispose()
MyBase.Dispose()
End Sub
End Class
End Namespace
■ 测试用户控件
右键单击"解决方案"，选择"添加|新建项目"，为解决方案添加一个测试用户控件的项目。并在窗体上添加一个CustomerControl控件和两个Button控件。
'这些必不可少
Imports System
Imports System.ComponentModel
Imports System.Drawing
Imports System.Windows.Forms
Imports Microsoft.Samples.WinForms.VB.CustomerControl
Imports Microsoft.VisualBasic.ControlChars
Namespace Microsoft.Samples.WinForms.VB.HostApp
Public Class HostApp
Inherits System.Windows.Forms.Form
Public Sub New()
MyBase.New()
HostApp = Me
'This call is required by the Windows Forms Designer.
InitializeComponent()
'TODO: Add any initialization after the InitializeComponent() call
CustomerControl1.Customer = Customer.ReadCustomer()
' Set the minimum form size to the client size + the height of the title bar
Me.MinimumSize = New Size(400,(373 + SystemInformation.TextHeight))
End Sub
'Form overrides dispose to clean up the component list.
Public Overloads Overrides Sub Dispose()
MyBase.Dispose()
components.Dispose()
End Sub
Private Sub buttonCancel_Click(ByVal sender As Object,ByVal e As System.EventArgs) Handles buttonCancel.Click
CustomerControl1.RejectChanges()
End Sub
Private Sub buttonSave_Click(ByVal sender As Object,ByVal e As System.EventArgs) Handles buttonSave.Click
CustomerControl1.AcceptChanges()
MessageBox.Show("Customer Changes Saved: " & CrLf & CustomerControl1.Customer.ToString)
End Sub
<STAThread()> Shared Sub Main()
Application.Run(New HostApp())
End Sub
End Class 'HostApp
End Namespace
■ 运行程序
单击菜单"调试|启动"或单击 图标运行程序。
小结
我们在本实例中自制了一个AcitveX控件，此控件具有定时提示的作用。读者可以自行开发控件，最后将该控件发布即可。