colortypeeditorcontrol.vb

ASP.NET服务器控件高级编程电子书

imports System
imports System.Collections
imports System.ComponentModel
imports System.Drawing
imports System.Data
imports System.Windows.Forms
imports System.Windows.Forms.Design
imports System.Web.UI.WebControls

Namespace WroxDesignVB.Design

    '/ <summary>
    '/ A custom UI editor for colors.
    '/ </summary>
    <ToolboxItem(False)> _
    Public Class ColorTypeEditorControl : Inherits System.Windows.Forms.UserControl

        Private label1 As System.Windows.Forms.Label
        Private label2 As System.Windows.Forms.Label
        Private label3 As System.Windows.Forms.Label
        Private pnlSample As System.Windows.Forms.Panel
        Private WithEvents trkAlpha As System.Windows.Forms.TrackBar
        Private WithEvents trkRed As System.Windows.Forms.TrackBar
        Private WithEvents trkGreen As System.Windows.Forms.TrackBar
        Private WithEvents trkBlue As System.Windows.Forms.TrackBar
        Private label5 As System.Windows.Forms.Label
        Private txtSample As System.Windows.Forms.Label
        Private WithEvents btnPicker As System.Windows.Forms.Button
        '/ <summary> 
        '/ Required designer variable.
        '/ </summary>
        Private components As System.ComponentModel.Container = Nothing

        'Variable keeping the current color selection. It is initialized to black.
        Private _color As Color = Color.Black
        Private _component As WebControl

        '/ <summary>
        '/ Constructor of the user control.
        '/ </summary>
        '/ <param name="colorToEdit">The color which is going to be edited.</param>
        Public Sub New(ByVal colorToEdit As Color, ByVal component As WebControl)

            ' me call is required by the Windows.Forms Form Designer.
            InitializeComponent()

            _component = component

            'Initialize controls.
            _color = colorToEdit
            trkAlpha.Value = _color.A
            trkBlue.Value = _color.B
            trkGreen.Value = _color.G
            trkRed.Value = _color.R
            pnlSample.BackColor = _color
        End Sub

        '/ <summary> 
        '/ Clean up any resources being used.
        '/ </summary>
        Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
            If (disposing) Then
                If Not (components Is Nothing) Then
                    components.Dispose()
                    MyBase.Dispose(disposing)
                End If
            End If
        End Sub

#Region "Component Designer generated code"
        '/ <summary> 
        '/ Required method for Designer support - do not modify 
        '/ the contents of me method with the code editor.
        '/ </summary>
        Private Sub InitializeComponent()
            Me.btnPicker = New System.Windows.Forms.Button()
            Me.label1 = New System.Windows.Forms.Label()
            Me.label2 = New System.Windows.Forms.Label()
            Me.label3 = New System.Windows.Forms.Label()
            Me.trkRed = New System.Windows.Forms.TrackBar()
            Me.pnlSample = New System.Windows.Forms.Panel()
            Me.txtSample = New System.Windows.Forms.Label()
            Me.trkBlue = New System.Windows.Forms.TrackBar()
            Me.trkAlpha = New System.Windows.Forms.TrackBar()
            Me.label5 = New System.Windows.Forms.Label()
            Me.trkGreen = New System.Windows.Forms.TrackBar()
            CType(Me.trkRed, System.ComponentModel.ISupportInitialize).BeginInit()
            CType(Me.trkBlue, System.ComponentModel.ISupportInitialize).BeginInit()
            CType(Me.trkAlpha, System.ComponentModel.ISupportInitialize).BeginInit()
            CType(Me.trkGreen, System.ComponentModel.ISupportInitialize).BeginInit()
            Me.SuspendLayout()
            '
            'btnPicker
            '
            Me.btnPicker.FlatStyle = System.Windows.Forms.FlatStyle.Flat
            Me.btnPicker.Location = New System.Drawing.Point(148, 160)
            Me.btnPicker.Name = "btnPicker"
            Me.btnPicker.Size = New System.Drawing.Size(48, 20)
            Me.btnPicker.TabIndex = 4
            Me.btnPicker.Text = "Picker"
            '
            'label1
            '
            Me.label1.Location = New System.Drawing.Point(8, 48)
            Me.label1.Name = "label1"
            Me.label1.Size = New System.Drawing.Size(40, 16)
            Me.label1.TabIndex = 0
            Me.label1.Text = "Red: inherits"
            '
            'label2
            '
            Me.label2.Location = New System.Drawing.Point(8, 80)
            Me.label2.Name = "label2"
            Me.label2.Size = New System.Drawing.Size(40, 16)
            Me.label2.TabIndex = 0
            Me.label2.Text = "Green: inherits"
            '
            'label3
            '
            Me.label3.Location = New System.Drawing.Point(8, 112)
            Me.label3.Name = "label3"
            Me.label3.Size = New System.Drawing.Size(40, 16)
            Me.label3.TabIndex = 0
            Me.label3.Text = "Blue: inherits"
            '
            'trkRed
            '
            Me.trkRed.AutoSize = False
            Me.trkRed.Location = New System.Drawing.Point(52, 44)
            Me.trkRed.Maximum = 255
            Me.trkRed.Name = "trkRed"
            Me.trkRed.Size = New System.Drawing.Size(144, 45)
            Me.trkRed.SmallChange = 10
            Me.trkRed.TabIndex = 3
            '
            'pnlSample
            '
            Me.pnlSample.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
            Me.pnlSample.Location = New System.Drawing.Point(8, 184)
            Me.pnlSample.Name = "pnlSample"
            Me.pnlSample.Size = New System.Drawing.Size(188, 16)
            Me.pnlSample.TabIndex = 2
            '
            'txtSample
            '
            Me.txtSample.Location = New System.Drawing.Point(8, 164)
            Me.txtSample.Name = "txtSample"
            Me.txtSample.Size = New System.Drawing.Size(76, 16)
            Me.txtSample.TabIndex = 1
            Me.txtSample.Text = "Sample Color: inherits"
            '
            'trkBlue
            '
            Me.trkBlue.AutoSize = False
            Me.trkBlue.Location = New System.Drawing.Point(52, 108)
            Me.trkBlue.Maximum = 255
            Me.trkBlue.Name = "trkBlue"
            Me.trkBlue.Size = New System.Drawing.Size(144, 45)
            Me.trkBlue.SmallChange = 10
            Me.trkBlue.TabIndex = 3
            '
            'trkAlpha
            '
            Me.trkAlpha.AutoSize = False
            Me.trkAlpha.Location = New System.Drawing.Point(52, 12)
            Me.trkAlpha.Maximum = 255
            Me.trkAlpha.Name = "trkAlpha"
            Me.trkAlpha.Size = New System.Drawing.Size(144, 45)
            Me.trkAlpha.SmallChange = 10
            Me.trkAlpha.TabIndex = 3
            '
            'label5
            '
            Me.label5.Location = New System.Drawing.Point(8, 16)
            Me.label5.Name = "label5"
            Me.label5.Size = New System.Drawing.Size(40, 16)
            Me.label5.TabIndex = 0
            Me.label5.Text = "Alpha: inherits"
            '
            'trkGreen
            '
            Me.trkGreen.AutoSize = False
            Me.trkGreen.Location = New System.Drawing.Point(52, 76)
            Me.trkGreen.Maximum = 255
            Me.trkGreen.Name = "trkGreen"
            Me.trkGreen.Size = New System.Drawing.Size(144, 45)
            Me.trkGreen.SmallChange = 10
            Me.trkGreen.TabIndex = 3
            '
            'ColorTypeEditorControl
            '
            Me.BackColor = System.Drawing.Color.FromArgb(CType(153, Byte), CType(153, Byte), CType(255, Byte))
            Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.btnPicker, Me.txtSample, Me.trkBlue, Me.trkGreen, Me.trkRed, Me.pnlSample, Me.label3, Me.label2, Me.label1, Me.label5, Me.trkAlpha})
            Me.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
            Me.Name = "ColorTypeEditorControl"
            Me.Size = New System.Drawing.Size(204, 208)
            CType(Me.trkRed, System.ComponentModel.ISupportInitialize).EndInit()
            CType(Me.trkBlue, System.ComponentModel.ISupportInitialize).EndInit()
            CType(Me.trkAlpha, System.ComponentModel.ISupportInitialize).EndInit()
            CType(Me.trkGreen, System.ComponentModel.ISupportInitialize).EndInit()
            Me.ResumeLayout(False)

        End Sub
#End Region

        Private Sub OnColorChanged(ByVal sender As Object, ByVal e As EventArgs) Handles trkAlpha.ValueChanged, _
            trkBlue.ValueChanged, trkGreen.ValueChanged, trkRed.ValueChanged
            _color = Color.FromArgb(trkAlpha.Value, trkRed.Value, trkGreen.Value, trkBlue.Value)
            pnlSample.BackColor = _color
            '_component.BackColor = _color	'me won't work!
            'PropertyDescriptorCollection col = TypeDescriptor.GetProperties(_component)
            'col"BackColor", _.SetValue(_component, _color)
            'Resumed version of the previous 2 lines
            TypeDescriptor.GetProperties(_component).Item("BackColor").SetValue(_component, _color)
        End Sub

        Private Sub btnPicker_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnPicker.Click

            '			ColorDialog dlg = new ColorDialog()
            '			dlg.Color = _color
            '			if (dlg.ShowDialog() == DialogResult.OK) _color = dlg.Color

            Dim tc As TypeConverter = TypeDescriptor.GetConverter(_color)

            Dim res As String = System.Web.UI.Design.ColorBuilder.BuildColor(_component, _
                    Me, tc.ConvertToString(_color))

            If (res <> String.Empty And res <> Nothing) Then
                _color = CType(tc.ConvertFromString(res), Color)
            End If
        End Sub

        Friend ReadOnly Property SelectedColor() As Color
            Get
                Return _color
            End Get
        End Property

    End Class
End Namespace