一个使用用户控件（包括组件）的演示。

1.
Imports System.ComponentModel
Public Class pic
Inherits System.Windows.Forms.UserControl
#Region " Windows 窗体设计器生成的代码 "

'UserControl1 重写 dispose 以清理组件列表。
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub
'Windows 窗体设计器所必需的
Private components As System.ComponentModel.IContainer
'注意：以下过程是 Windows 窗体设计器所必需的
'可以使用 Windows 窗体设计器修改此过程。
'不要使用代码编辑器修改它。
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
'
'pic
'
Me.Name = "pic"
Me.Size = New System.Drawing.Size(48, 48)
End Sub
#End Region
Public Const m_maxlen As Integer = 48 '固定的宽和高
Public Const m_maxheight As Integer = 48
Public Sub New(ByVal m As image) '主要是用于在piccontrols组件中创建实例时使用
MyBase.New()
'该调用是 Windows 窗体设计器所必需的。
InitializeComponent()
'在 InitializeComponent() 调用之后添加任何初始化
m_image = m
End Sub
Public Sub New()
MyBase.New()
'该调用是 Windows 窗体设计器所必需的。
InitializeComponent()
'在 InitializeComponent() 调用之后添加任何初始化
End Sub
Private m_image As image = image.FromFile("G:/练习/重要的例程/使用问题（在格子中显示图片）/Gounda Takeshi.ico")
<Category("grid"), Description("设置卡片的图片。")> _
Public Property image() As image
Get
Return m_image
End Get
Set(ByVal Value As image)
m_image = Value
Me.Refresh()
End Set
End Property
'绘制边框和图象
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
Dim g As Graphics = Me.CreateGraphics
Me.BackColor = Color.White
g.DrawRectangle(System.Drawing.Pens.Black, 0, 0, Me.Width - 1, Me.Height - 1)
Dim ic As Image = CType(m_image, Image)
g.DrawImage(ic, 0, 0)
End Sub
'不允许调整大小
Protected Overrides Sub OnSizeChanged(ByVal e As System.EventArgs)
Me.Size = New Size(m_maxlen, m_maxheight)
End Sub
'匹配否标志
Private m_double As Boolean = False
<Category("grid"), Description("是否匹配的标志。")> _
Public Property doubles() As Boolean
Get
Return m_double
End Get
Set(ByVal Value As Boolean)
m_double = Value
End Set
End Property
Private m_id As Integer
<Category("grid"), Description("区分是否来自同一图片的标志。")> _
Public Property id() As Integer
Get
Return m_id
End Get
Set(ByVal Value As Integer)
m_id = Value
End Set
End Property

End Class

2.
Imports my_namespace
Imports System.ComponentModel
Public Class piccontrols
Inherits System.ComponentModel.Component
#Region " 组件设计器生成的代码 "

'组件重写 dispose 以清理组件列表。
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub
'组件设计器所必需的
Private components As System.ComponentModel.IContainer
'注意：以下过程是组件设计器所必需的
'可以使用组件设计器修改此过程。
'不要使用代码编辑器修改它。
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
End Sub
#End Region
Public Sub New(ByVal Container As System.ComponentModel.IContainer)
MyClass.New()
'Windows.Forms 类撰写设计器支持所必需的
Container.Add(Me)
changepic() '如果选择的图片发生了变化，那么创建卡片集合也要相应的变化。
End Sub
Public Sub New()
MyBase.New()
'该调用是组件设计器所必需的。
InitializeComponent()
'在 InitializeComponent() 调用之后添加任何初始化
changepic() '如果选择的图片发生了变化，那么创建卡片集合也要相应的变化。
End Sub
'////////////////////////////////////////////////////////////////
Dim m_piccontrols As New System.Collections.ArrayList()
'总数量
<Category("grid"), Description("集合内卡片的总数。")> _
Public ReadOnly Property count() As Integer
Get
Return m_piccontrols.Count
End Get
End Property
'指定位置的卡片(这个对于vb.net是比较特殊的，具有带参数的属性)
Default Public ReadOnly Property items(ByVal index As Integer) As pic
Get
If index >= 0 And index < m_piccontrols.Count Then
Return CType(m_piccontrols(index), pic)
End If
End Get
End Property
Public Sub shuffle() ' 混卡片,也就是生成一组随机的卡片集合。(这里的算法不错！)
Dim r As New System.Random()
Dim d As New System.Collections.ArrayList()
Dim p As pic
While (m_piccontrols.Count > 0)
Dim removeindex As Integer = r.Next(0, m_piccontrols.Count - 1)
p = CType(m_piccontrols(removeindex), my_namespace.pic)
m_piccontrols.RemoveAt(removeindex)
d.Add(p)
End While
m_piccontrols = d
End Sub
Private m_image As imagelist
<Category("grid"), Description("选择相应的imagelist控件。")> _
Public Property imagelist() As imagelist
Get
Return m_image
End Get
Set(ByVal Value As imagelist)
m_image = Value
changepic()
End Set
End Property
'/////////
'这个事件比较重要，主要是根据图片的变动来生成不同的卡片集合。
Private Sub changepic()
If m_image Is Nothing Then Exit Sub
Dim i As Integer
For i = 0 To m_piccontrols.Count - 1
CType(m_piccontrols(i), pic).Dispose() '注意这里。
Next
m_piccontrols.Clear()
Dim j As Integer
For i = 0 To m_image.Images.Count - 1
For j = 0 To 3
Dim p As New pic(m_image.Images(i))
p.id = i
m_piccontrols.Add(p)
Next
Next
End Sub
'由于在排列好后，每个在集合中的卡片的doubles属性都会被设置成true,
'所以要在开始一次新的排序时设置所有的卡片该属性为false
Public Sub setfalse()
Dim i As Integer
For i = 0 To m_piccontrols.Count - 1
Dim apic As pic = CType(m_piccontrols(i), pic)
apic.doubles = False
Next
End Sub
End Class

3.
Imports System.ComponentModel
Public Class picshow
Inherits System.Windows.Forms.UserControl
#Region " Windows 窗体设计器生成的代码 "
Public Sub New()
MyBase.New()
'该调用是 Windows 窗体设计器所必需的。
InitializeComponent()
'在 InitializeComponent() 调用之后添加任何初始化
End Sub
'UserControl 重写 dispose 以清理组件列表。
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub
'Windows 窗体设计器所必需的
Private components As System.ComponentModel.IContainer
'注意：以下过程是 Windows 窗体设计器所必需的
'可以使用 Windows 窗体设计器修改此过程。
'不要使用代码编辑器修改它。
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
End Sub
#End Region
'// 这个程序的原理 //
'//先做一个pic控件，可以为其设置相应的图片，不允许改变大小，要重写sizechange,onpait事件 //
'//做一个集合组件piccontrols来容纳一定数量的pic卡片，但并不显示它，因为是组件。只是容器 //
'//最后做一个picshow控件，用于显示piccontrols.count数量的卡片集合。 //
'//比较重要的地方就是如何对卡片进行随机混排（piccontrols的shuffle方法）和picshow控件的 //
'//contrains，start方法。尤其注意这里进行排序的方法：是将卡片在集合里就弄混（随机），这样//
'//我们取得的每个卡片都是随机的了，然后在picshow控件里根据每个卡片的doubles,id属性来进行 //
'//排序，把随机和排序分开了。当然也可以把他们合并写到picshow控件里。不过这里不建议这样。 //
'//因为对于piccontrols组件来说，它的集合就是一个随机产生的卡片集合。这样比较好理解。 //
Private Const m_spacing As Integer = 10 '间隔设置的常量
Private m_rows As Integer = 2 ' 对于一个阵列来讲，2行应该更有意义。
<Category("grid"), Description("矩阵的行。"), DefaultValue(2)> _
Public Property row() As Integer
Get
Return m_rows
End Get
Set(ByVal Value As Integer)
If Value > 0 Then
m_rows = Value
Me.Refresh()
End If
End Set
End Property
Private m_columns As Integer = 2
<Category("grid"), Description("矩阵的列。"), DefaultValue(2)> _
Public Property columns() As Integer
Get
Return m_columns
End Get
Set(ByVal Value As Integer)
If (Value > 0) And (Value Mod 2 = 0) Then
m_columns = Value
Me.Refresh()
Else
Throw New Exception("不是有效的列值！请输入2的倍数的列值。")
End If
End Set
End Property
Private m_collection As piccontrols
<Category("grid"), Description("指定相应的piccontrols组件。")> _
Public Property getcontrols() As piccontrols
Get
Return m_collection
End Get
Set(ByVal Value As piccontrols)
m_collection = Value
End Set
End Property
'绘制边框，由于还没有将卡片加入到me.controls集合，所以只有边框。
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
Dim height As Integer = my_namespace.pic.m_maxheight
Dim width As Integer = my_namespace.pic.m_maxlen
Me.Width = (width + m_spacing) * m_columns + m_spacing
Me.Height = (height + m_spacing) * m_rows + m_spacing
Dim g As Graphics = Me.CreateGraphics
Dim row, column As Integer
For row = 0 To m_rows - 1
For column = 0 To m_columns - 1
g.DrawRectangle(System.Drawing.Pens.Gray, column * (width + m_spacing) + m_spacing, _
row * (height + m_spacing) + m_spacing, width, height)
Next
Next
End Sub
Private m_double As pic '记录相同的那个卡片
Private m_last As Integer '记录格子中的最后一个卡片
'开始排列
Public Sub start()
Me.Controls.Clear() '先清空容器
If Not IsNothing(m_collection) Then '判断行列之积和卡片数量是否相等
If (m_collection.count <> m_rows * m_columns) Then
Throw New Exception("卡片数量为：" & CStr(m_collection.count) & "格子数量为：" & CStr(m_rows * m_columns))
End If
'///////////////////////////////////
m_last = -2 '初始化，因为从0开始是第一个格子，所以初始值为-2
m_collection.setfalse() '因为开始一次排序就会把所有的卡片pic的double属性全都设置为true。所以，这里要全都设置回false
m_collection.shuffle() '将卡片弄混
Dim cardcount As Integer = 0 '卡片指针
Dim row, column As Integer
For row = 0 To m_rows - 1
For column = 0 To m_columns - 1
Dim apic As pic = CType(m_collection(cardcount), pic)
'加入到me的控件集合
Me.Controls.Add(apic)
'控件集合中的原有卡片进行遍历，看是否有单个的与新加入的同一个图片的卡片
Dim rint As Integer = contrains(apic)
Select Case rint
Case 0 '匹配排列
apic.Left = m_double.Left + m_spacing + my_namespace.pic.m_maxlen
apic.Top = m_double.Top
Case 1 '没有匹配项，间隔排列
'行,注意一定要使用int进行转化，否则会四舍五入。
Dim r As Integer = Int(m_last / (m_rows))
'列
Dim c As Integer = m_last Mod (m_rows)
'取得行列后就可以直接设置位置了。
apic.Left = c * (pic.m_maxlen + m_spacing) + m_spacing
apic.Top = r * (pic.m_maxheight + m_spacing) + m_spacing
End Select
cardcount += 1 '下一个卡片
Next
Next
MessageBox.Show("排序完成！")
End If
End Sub
'排序的函数
Public Function contrains(ByVal p As pic) As Integer
m_double = Nothing '初始值为空，每次排序前要设置为空。
Dim apic As pic
Dim i As Integer
Dim count As Integer = Me.Controls.Count - 1
For i = 0 To count - 1 '从0到末尾-1，把自己排除掉，自己和自己不必要去比较
apic = CType(Me.Controls(i), pic)
If (apic.id = p.id) And apic.doubles = False Then 'And i <> count
apic.doubles = True '匹配
p.doubles = True '匹配
m_double = apic
End If
Next
'找到匹配的了
If Not (m_double Is Nothing) Then
Return 0
Else
m_last += 2 '分隔开一个格子( 这里的格子开始为0，最后为m_collection的count-1)
Return 1
End If
End Function
End Class