Software Expressions
Archive for November, 2008
I am always dazzled with your consistency and your practical approach to issues. You surely must be brilliant for being able to create the architecture we have - QA Lead
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11 14th, 2008Button theory
Author: TroyButtons on Windows applications have been around since the first version of Windows. One would think that the patterns for using buttons would have been firmly established by now. In particular rules for disabling and enabling buttons.
Concerning visibility:
Concerning enable and disable:
11 14th, 2008Serializing images
Author: TroyThe System.Drawing.Image class is not serializable by default. This class can be used to serialize images as well as load the image from the IDataRecord.
1: Imports System.Drawing
2: Imports System.Runtime.Serialization
3: Imports System.Drawing.Imaging
4: Imports System.IO
5:
6: <Serializable()> _
7: Public Class SerializableImage
8: Implements ISerializable
9:
10: Private _master As MasterEnum = MasterEnum.Image
11: Private _imageBuffer As Byte()
12: Private _image As Image
13: Private _serializationFormat As ImageFormat = ImageFormat.Png
14:
15: Public Property Image() As Image
16: Get
17: If _master <> MasterEnum.Image Then
18: CreateImageFromBuffer()
19: End If
20: Return _image
21: End Get
22: Set(ByVal value As Image)
23: If (value Is _image) Then Return
24: _image = value
25: ‘The image becomes the master once the setter is used
26: _master = MasterEnum.Image
27: _imageBuffer = Nothing
28: End Set
29: End Property
30:
31: Private Sub CreateImageFromBuffer()
32: ‘Once this method is called, the image becomes the master
33: _master = MasterEnum.Image
34: ‘Check if there is a buffer
35: If _imageBuffer Is Nothing OrElse _imageBuffer.Length = 0 Then
36: Image = Nothing
37: Else
38: ‘http://support.microsoft.com/?id=814675
39: Using s As New MemoryStream(_imageBuffer)
40: If Not s Is System.IO.Stream.Null Then
41: Dim tempImage As Image = _
42: DirectCast(Bitmap.FromStream(s), Bitmap)
43: Image = New Bitmap(tempImage)
44: Dim g As Graphics = Graphics.FromImage(tempImage)
45: g.DrawImage(Image, New PointF(0, 0))
46: g.Dispose()
47: tempImage.Dispose()
48: End If
49: s.Close()
50: End Using
51: End If
52: End Sub
53:
54: Private Property ImageBuffer() As Byte()
55: Get
56: Select Case _master
57: Case MasterEnum.Image
58: ‘Used for serialization
59: Return CreateBufferFromImage()
60: Case MasterEnum.Buffer
61: Return _imageBuffer
62: End Select
63: Return _imageBuffer
64: End Get
65: Set(ByVal value As Byte())
66: If (value Is _imageBuffer) Then Return
67: _imageBuffer = value
68: ‘The Buffer becomes the master
69: _master = MasterEnum.Buffer
70: _image = Nothing
71: End Set
72: End Property
73:
74: Private Function CreateBufferFromImage() As Byte()
75: If _image Is Nothing Then Return Nothing
76: ‘Convert the image to a byte array using the serialization format
77: Using stream As New MemoryStream
78: _image.Save(stream, SerializationFormat)
79: Dim result As Byte() = stream.ToArray()
80: stream.Close()
81: Return result
82: End Using
83: End Function
84:
85: Public Property SerializationFormat() As ImageFormat
86: Get
87: Return _serializationFormat
88: End Get
89: Set(ByVal value As ImageFormat)
90: _serializationFormat = value
91: End Set
92: End Property
93:
94: Public Sub New()
95:
96: End Sub
97:
98: Public Sub New(ByVal image As Image)
99: Me.Image = image
100: End Sub
101:
102: Public Sub New(ByVal record As IDataRecord, ByVal fieldIndex As Integer)
103: Load(record, fieldIndex)
104: End Sub
105:
106: Public Sub New(ByVal record As IDataRecord, ByVal fieldName As String)
107: Load(record, fieldName)
108: End Sub
109:
110: Private Sub Load(ByVal record As IDataRecord, ByVal fieldName As String)
111: If record Is Nothing Then Throw New ArgumentNullException(“record”)
112: Load(record, record.GetOrdinal(fieldName))
113: End Sub
114:
115: Private Sub Load(ByVal record As IDataRecord, ByVal fieldIndex As Integer)
116: If record Is Nothing Then Throw New ArgumentNullException(“record”)
117: If record.IsDBNull(fieldIndex) Then Return
118: ImageBuffer = DirectCast(record.GetValue(fieldIndex), Byte())
119: End Sub
120:
121: Public Sub New(ByVal info As SerializationInfo, _
122: ByVal context As StreamingContext)
123: ‘Image
124: Dim data As Byte() = _
125: DirectCast(info.GetValue(“image”, GetType(Byte())), Byte())
126: If data IsNot Nothing AndAlso data.Length > 0 Then
127: ‘http://support.microsoft.com/?id=814675
128: Using s As New MemoryStream(data)
129: If Not s Is System.IO.Stream.Null Then
130: Dim tempImage As Image = _
131: DirectCast(Bitmap.FromStream(s), Bitmap)
132: Image = New Bitmap(tempImage)
133: Dim g As Graphics = Graphics.FromImage(tempImage)
134: g.DrawImage(Image, New PointF(0, 0))
135: g.Dispose()
136: tempImage.Dispose()
137: End If
138: s.Close()
139: End Using
140: End If
141: End Sub
142:
143: Public Sub GetObjectData(ByVal info As SerializationInfo, +
144: ByVal context As StreamingContext) Implements ISerializable.GetObjectData
145: info.AddValue(“image”, ImageBuffer, GetType(Byte()))
146: End Sub
147:
148: Private Enum MasterEnum
149: Buffer
150: Image
151: End Enum
152:
153: End Class
11 14th, 2008Some friends were experiencing problems with a virus (run32dll - possibly WhisperB-worm), while searching for the best approach to resolve this issue I came across this really simple and impressive article. I guess I’m rather old-school when it comes to viruses and haven’t dealt much with them for many years. Back in the DOS days you would create a boot disk with your virus software. You would boot up on the clean boot disk, and run the scan on C:. There was nothing else to it. It seems to be rather more complicated these days - and I’m not sure it needs to be. For one thing, how can you download virus scanning software and run it on a machine with a virus? How can you run a Windows virus scanning software on a machine where when Windows starts up it already has the virus loaded. This was evidently the problem in this case because the virus scanners that were downloaded picked up no viruses. Indeed the virus software had cleverly intercepted the scanner. It was obvious because during the scan the machine would reboot. The scanning software couldn’t even download all it’s updated virus signatures…
http://askthegeek.kennyhart.com/2005/12/how-to-make-bootable-thumb-drive-virus.html