Write a DLL

[Erdenemandal]

Hi, ALL

 

I am writing a DLL in VB.NET, But I habe a problem. I want to draw a Graphic

 

This is my DLL class

 

' MyClassLibrary
' 2003/09/04 Copyright 2003, Larry Rebich


Imports System.Drawing

Public Class clsMyClass
       Private mMyName As String

       Property MyName() As String
               Get
                       MyName = mMyName
               End Get
               Set(ByVal Value As String)
                       mMyName = Value
               End Set
       End Property

       Public Function GetDate() As String
               ' Return today's date
               Return "Today is " & Today
       End Function

       Public Sub DrawResult(ByRef Obj As Windows.Forms.Panel, _
                ByRef TotalHit As Integer, _
                ByRef RightHit As Integer, _
                ByRef FormObj As Windows.Forms.TabPage)

               Obj.Visible = False

               ' Get a Graphics object from the current form and clear its background.

               Dim gr As Graphics = FormObj.CreateGraphics

               Dim mPen As New Pen(Color.White, 2)
               Dim mPen2 As New Pen(Color.RoyalBlue.Black, 1)

               Dim TotalProzent, Total2 As Integer


               Dim rr As New Rectangle(Obj.Left, Obj.Top, Obj.Width, Obj.Height)
               gr.FillRectangle(Brushes.White, rr)
               

               TotalProzent = Int(RightHit / TotalHit * 360)

               ' Draw a green filled rectangle.

               Dim x, y, mWidth, mHeight, StartAngle, SweepAngle As Integer

               x = Obj.Left + 10
               y = Obj.Top + 10
               mHeight = Obj.Height - 20
               mWidth = Obj.Width - 20

               ' Draw a red pie (portion of an ellipse).
               Dim i, j As Integer
               For i = 0 To TotalProzent
                       gr.FillPie(Brushes.Blue, x, y, mWidth, mHeight, 0, i)
               Next


               gr.DrawPie(mPen2, x, y, mWidth, mHeight, 0, TotalProzent)

               Total2 = 360 - TotalProzent

               For i = 0 To Total2
                       gr.FillPie(Brushes.Red, x, y, mWidth, mHeight, TotalProzent, i)
               Next

               gr.DrawPie(mPen2, x, y, mWidth, mHeight, TotalProzent, Total2)
               gr.Dispose()
               
       End Sub
End Class

 

and I generate DLL and use it ni another form.

 

Public Class frmMySampleUseClassLibraryProject

       Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

       Public Sub New()
               MyBase.New()

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

               'Add any initialization after the InitializeComponent() call

       End Sub

       'Form overrides dispose to clean up the component list.
       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

       'Required by the Windows Form Designer
       Private components As System.ComponentModel.IContainer

       'NOTE: The following procedure is required by the Windows Form Designer
       'It can be modified using the Windows Form Designer.  
       'Do not modify it using the code editor.
       Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
       Friend WithEvents Label1 As System.Windows.Forms.Label
       Friend WithEvents Label2 As System.Windows.Forms.Label
       Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
       Friend WithEvents TabControl1 As System.Windows.Forms.TabControl
       Friend WithEvents TabPage1 As System.Windows.Forms.TabPage
       Friend WithEvents Panel1 As System.Windows.Forms.Panel
       <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
               Me.TextBox1 = New System.Windows.Forms.TextBox
               Me.Label1 = New System.Windows.Forms.Label
               Me.Label2 = New System.Windows.Forms.Label
               Me.TextBox2 = New System.Windows.Forms.TextBox
               Me.TabControl1 = New System.Windows.Forms.TabControl
               Me.TabPage1 = New System.Windows.Forms.TabPage
               Me.Panel1 = New System.Windows.Forms.Panel
               Me.TabControl1.SuspendLayout()
               Me.TabPage1.SuspendLayout()
               Me.SuspendLayout()
               '
               'TextBox1
               '
               Me.TextBox1.Location = New System.Drawing.Point(96, 16)
               Me.TextBox1.Name = "TextBox1"
               Me.TextBox1.ReadOnly = True
               Me.TextBox1.Size = New System.Drawing.Size(328, 20)
               Me.TextBox1.TabIndex = 0
               Me.TextBox1.Text = "TextBox1"
               '
               'Label1
               '
               Me.Label1.AutoSize = True
               Me.Label1.Location = New System.Drawing.Point(40, 24)
               Me.Label1.Name = "Label1"
               Me.Label1.Size = New System.Drawing.Size(38, 16)
               Me.Label1.TabIndex = 1
               Me.Label1.Text = "Name:"
               Me.Label1.TextAlign = System.Drawing.ContentAlignment.MiddleRight
               '
               'Label2
               '
               Me.Label2.AutoSize = True
               Me.Label2.Location = New System.Drawing.Point(40, 56)
               Me.Label2.Name = "Label2"
               Me.Label2.Size = New System.Drawing.Size(31, 16)
               Me.Label2.TabIndex = 3
               Me.Label2.Text = "Date:"
               Me.Label2.TextAlign = System.Drawing.ContentAlignment.MiddleRight
               '
               'TextBox2
               '
               Me.TextBox2.Location = New System.Drawing.Point(96, 48)
               Me.TextBox2.Name = "TextBox2"
               Me.TextBox2.ReadOnly = True
               Me.TextBox2.Size = New System.Drawing.Size(328, 20)
               Me.TextBox2.TabIndex = 2
               Me.TextBox2.Text = "TextBox2"
               '
               'TabControl1
               '
               Me.TabControl1.Controls.Add(Me.TabPage1)
               Me.TabControl1.Location = New System.Drawing.Point(32, 104)
               Me.TabControl1.Name = "TabControl1"
               Me.TabControl1.SelectedIndex = 0
               Me.TabControl1.Size = New System.Drawing.Size(416, 200)
               Me.TabControl1.TabIndex = 4
               '
               'TabPage1
               '
               Me.TabPage1.Controls.Add(Me.Panel1)
               Me.TabPage1.Location = New System.Drawing.Point(4, 22)
               Me.TabPage1.Name = "TabPage1"
               Me.TabPage1.Size = New System.Drawing.Size(408, 174)
               Me.TabPage1.TabIndex = 0
               Me.TabPage1.Text = "TabPage1"
               '
               'Panel1
               '
               Me.Panel1.BackColor = System.Drawing.SystemColors.ControlText
               Me.Panel1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
               Me.Panel1.Location = New System.Drawing.Point(24, 16)
               Me.Panel1.Name = "Panel1"
               Me.Panel1.Size = New System.Drawing.Size(360, 144)
               Me.Panel1.TabIndex = 0
               '
               'frmMySampleUseClassLibraryProject
               '
               Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
               Me.ClientSize = New System.Drawing.Size(464, 314)
               Me.Controls.Add(Me.TabControl1)
               Me.Controls.Add(Me.Label2)
               Me.Controls.Add(Me.TextBox2)
               Me.Controls.Add(Me.Label1)
               Me.Controls.Add(Me.TextBox1)
               Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedToolWindow
               Me.MaximizeBox = False
               Me.Name = "frmMySampleUseClassLibraryProject"
               Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
               Me.Text = "frmMySampleUseClassLibraryProject"
               Me.TabControl1.ResumeLayout(False)
               Me.TabPage1.ResumeLayout(False)
               Me.ResumeLayout(False)

       End Sub

#End Region

       Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
               UseMyClass()

       End Sub

       Private Sub UseMyClass()

               Dim yy1, yy2 As Integer

               yy1 = 100
               yy2 = 50


               Dim obj As New MyClassLibrary.clsMyClass
               With obj
                       .MyName = "Larry Rebich"
                       Me.TextBox1.Text = .MyName
                       Me.TextBox2.Text = .GetDate()
                       .DrawResult(Panel1, yy1, yy2, Me.TabControl1.TabPages(0))
               End With

       End Sub
End Class

 

 

Everything works fine with String and Integer type. But I can not see any Graphic ni my new form

 

Can somebody help me

 

Thanks,

Erdenemandal

[mutant]

You are calling the drawing routine during the Form's load event, when none of the controls is yet visible. When they do become visible, they will be redrawn in their original appearance since GDI+ does not keep the drawn modifications on controls. Try drawing on your control when the form is visible. But even then, if the control needs to be redrawn, it will loose any appearance modifications, so the best way to keep something drawn on the form/control is to draw it in the Paint event of the object.

[DiverDan]

To add to Mutant's reply:

Or reference the DrawResult sub from the form's/control's Paint event.

[Erdenemandal]

Thanks,

 

I call DrawResult in Paint event of the Form. It works as I wish

:p

Thanks,

Erdenemandal

[Kurt]

I seem to remember that when you draw to a picturebox, the graphics are retained and automatically redrawn when for example another form covered your form and is then minimized...