Scribble application buffered by Bitmap : Painter « GUI Applications « VB.Net Tutorial

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2. GUI Applications
3. Painter

Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports System.Math

public class ScribbleApplication
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class

Public Class Form1
    Private m_Bitmap As Bitmap
    Private m_Graphics As Graphics

    Private m_Drawing As Boolean
    Private m_X As Integer
    Private m_Y As Integer

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

    Private Sub mnuFileClear_Click(ByVal sender As System.Object, _
     ByVal e As System.EventArgs) Handles mnuFileClear.Click
        MakeNewBitmap()
    End Sub

    Private Sub MakeNewBitmap()
        Dim wid As Integer = picCanvas.ClientSize.Width
        Dim hgt As Integer = picCanvas.ClientSize.Height

        m_Bitmap = New Bitmap(wid, hgt)
        m_Graphics = Graphics.FromImage(m_Bitmap)

        m_Graphics.Clear(Me.BackColor)

        picCanvas.Image = m_Bitmap
    End Sub

    Private Sub picCanvas_MouseDown(ByVal sender As Object, _
     ByVal e As System.Windows.Forms.MouseEventArgs) Handles picCanvas.MouseDown
        m_Drawing = True
        m_X = e.X
        m_Y = e.Y
    End Sub

    Private Sub picCanvas_MouseMove(ByVal sender As Object, _
     ByVal e As System.Windows.Forms.MouseEventArgs) Handles picCanvas.MouseMove
        If Not m_Drawing Then Exit Sub

        m_Graphics.DrawLine(Pens.Black, m_X, m_Y, e.X, e.Y)
        m_X = e.X
        m_Y = e.Y

        picCanvas.Image = m_Bitmap
    End Sub

    Private Sub picCanvas_MouseUp(ByVal sender As Object, _
     ByVal e As System.Windows.Forms.MouseEventArgs) Handles picCanvas.MouseUp
        m_Drawing = False
    End Sub
End Class
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Public Class Form1
    Inherits System.Windows.Forms.Form

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing AndAlso components IsNot Nothing Then
            components.Dispose()
        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.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.picCanvas = New System.Windows.Forms.PictureBox
        Me.MenuStrip1 = New System.Windows.Forms.MenuStrip
        Me.mnuFile = New System.Windows.Forms.ToolStripMenuItem
        Me.mnuFileClear = New System.Windows.Forms.ToolStripMenuItem
        CType(Me.picCanvas, System.ComponentModel.ISupportInitialize).BeginInit()
        Me.MenuStrip1.SuspendLayout()
        Me.SuspendLayout()
        '
        'picCanvas
        '
        Me.picCanvas.Dock = System.Windows.Forms.DockStyle.Fill
        Me.picCanvas.Location = New System.Drawing.Point(0, 24)
        Me.picCanvas.Name = "picCanvas"
        Me.picCanvas.Size = New System.Drawing.Size(303, 246)
        Me.picCanvas.TabIndex = 0
        Me.picCanvas.TabStop = False
        '
        'MenuStrip1
        '
        Me.MenuStrip1.Items.AddRange(New System.Windows.Forms.ToolStripItem() {Me.mnuFile})
        Me.MenuStrip1.Location = New System.Drawing.Point(0, 0)
        Me.MenuStrip1.Name = "MenuStrip1"
        Me.MenuStrip1.Size = New System.Drawing.Size(303, 24)
        Me.MenuStrip1.TabIndex = 1
        Me.MenuStrip1.Text = "MenuStrip1"
        '
        'mnuFile
        '
        Me.mnuFile.DropDownItems.AddRange(New System.Windows.Forms.ToolStripItem() {Me.mnuFileClear})
        Me.mnuFile.Name = "mnuFile"
        Me.mnuFile.Text = "&File"
        '
        'mnuFileClear
        '
        Me.mnuFileClear.Name = "mnuFileClear"
        Me.mnuFileClear.Text = "&Clear"
        '
        'Form1
        '
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(303, 270)
        Me.Controls.Add(Me.picCanvas)
        Me.Controls.Add(Me.MenuStrip1)
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle
        Me.MainMenuStrip = Me.MenuStrip1
        Me.Name = "Form1"
        Me.Text = "Scribble"
        CType(Me.picCanvas, System.ComponentModel.ISupportInitialize).EndInit()
        Me.MenuStrip1.ResumeLayout(False)
        Me.ResumeLayout(False)
        Me.PerformLayout()

    End Sub
    Friend WithEvents picCanvas As System.Windows.Forms.PictureBox
    Friend WithEvents MenuStrip1 As System.Windows.Forms.MenuStrip
    Friend WithEvents mnuFile As System.Windows.Forms.ToolStripMenuItem
    Friend WithEvents mnuFileClear As System.Windows.Forms.ToolStripMenuItem

End Class

15.13.Painter
	15.13.1.	Scribble 1
	15.13.2.	Scribble application buffered by Bitmap
	15.13.3.	Shape Painter