.net pdf 417 reader ReadOnlyListBase in VB.NET

Maker PDF 417 in VB.NET ReadOnlyListBase

ReadOnlyListBase
Draw PDF-417 2d Barcode In Visual Basic .NET
Using Barcode creator for .NET framework Control to generate, create PDF 417 image in .NET applications.
www.OnBarcode.com
PDF417 Scanner In Visual Basic .NET
Using Barcode scanner for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Not only do applications sometimes need read-only business objects, but they also commonly require immutable collections of objects. The ReadOnlyListBase class lets you create strongly typed collections of objects whereby the object and collection are both read-only. <Serializable()> _ Public Class StaticList Inherits ReadOnlyListBase(Of StaticList, ChildType) End Class As with ReadOnlyBase, this object supports only the retrieval of data. It has no provision for updating data or handling changes to its data. While the child objects in such a collection may inherit from ReadOnlyBase, they don t have to. More commonly, the child objects in a read-only collection are just simple .NET objects that merely expose read-only properties.
1D Barcode Creation In VB.NET
Using Barcode creation for Visual Studio .NET Control to generate, create 1D Barcode image in .NET framework applications.
www.OnBarcode.com
ECC200 Printer In Visual Basic .NET
Using Barcode maker for .NET Control to generate, create Data Matrix image in VS .NET applications.
www.OnBarcode.com
NameValueListBase
Code 39 Generation In VB.NET
Using Barcode drawer for VS .NET Control to generate, create Code 39 Full ASCII image in VS .NET applications.
www.OnBarcode.com
Barcode Generator In Visual Basic .NET
Using Barcode creator for Visual Studio .NET Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
The NameValueListBase class is designed specifically to support the idea of lookup tables or lists of read-only key/value data such as categories, customer types, product types, and so forth. The goal of this class is to simplify the process of retrieving such data and displaying it in common controls like drop-down lists, combo boxes, and other list controls.
Paint Matrix 2D Barcode In Visual Basic .NET
Using Barcode printer for .NET Control to generate, create Matrix 2D Barcode image in .NET applications.
www.OnBarcode.com
Postnet Creation In Visual Basic .NET
Using Barcode generation for .NET framework Control to generate, create USPS POSTal Numeric Encoding Technique Barcode image in VS .NET applications.
www.OnBarcode.com
CHAPTER 2 s FRAMEWORK DESIGN
Paint PDF-417 2d Barcode In Visual C#
Using Barcode creator for Visual Studio .NET Control to generate, create PDF 417 image in Visual Studio .NET applications.
www.OnBarcode.com
PDF-417 2d Barcode Encoder In None
Using Barcode generation for Online Control to generate, create PDF-417 2d barcode image in Online applications.
www.OnBarcode.com
<Serializable()> _ Public Class CodeList Inherits NameValueListBase(Of Integer, String) End Class While the business developer does need to create a specific class for each type of name/value data, inheriting from this base class largely trivializes the process.
Print Matrix 2D Barcode In Visual C#.NET
Using Barcode encoder for VS .NET Control to generate, create Matrix image in .NET applications.
www.OnBarcode.com
Encode GTIN - 12 In Java
Using Barcode generator for Java Control to generate, create GS1 - 12 image in Java applications.
www.OnBarcode.com
N-Level Undo Functionality
Data Matrix 2d Barcode Creator In Objective-C
Using Barcode creator for iPad Control to generate, create ECC200 image in iPad applications.
www.OnBarcode.com
Barcode Recognizer In C#.NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
The implementation of n-level undo functionality is quite complex, and involves heavy use of reflection. Fortunately, we can use inheritance to place the implementation in a base class, so that no business object needs to worry about the undo code. In fact, to keep things cleaner, this code is in its own base class, separate from any other business object behaviors, as shown in Figure 2-11.
GTIN - 128 Scanner In Visual Basic .NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Generating ECC200 In C#
Using Barcode generation for .NET framework Control to generate, create DataMatrix image in Visual Studio .NET applications.
www.OnBarcode.com
Figure 2-11. Separating n-level undo into Core.UndoableBase
Quick Response Code Generator In C#.NET
Using Barcode generator for VS .NET Control to generate, create QR Code JIS X 0510 image in .NET framework applications.
www.OnBarcode.com
Make Code 128A In Java
Using Barcode creator for BIRT Control to generate, create Code 128 Code Set B image in BIRT reports applications.
www.OnBarcode.com
At first glance, it might appear that you could use .NET serialization to implement undo functionality: what easier way to take a snapshot of an object s state than to serialize it into a byte stream Unfortunately, this isn t as easy as it might sound, at least when it comes to restoring the object s state. Taking a snapshot of a <Serializable()> object is easy, and can be done with code similar to this:
Quick Response Code Generation In None
Using Barcode creator for Office Excel Control to generate, create QR Code 2d barcode image in Office Excel applications.
www.OnBarcode.com
EAN 13 Creation In Objective-C
Using Barcode generator for iPhone Control to generate, create UPC - 13 image in iPhone applications.
www.OnBarcode.com
CHAPTER 2 s FRAMEWORK DESIGN
<Serializable()> _ Public Class Customer Public Function Snapshot() As Byte() Using m As New MemoryStream Dim f As New BinaryFormatter f.Serialize(m, Me) m.Position = 0 return m.ToArray() End Using End Function End Class This converts the object into a byte stream, returning that byte stream as an array of type Byte. That part is easy it s the restoration that s tricky. Suppose that the user now wants to undo the changes, requiring that the byte stream be restored back into the object. The code that deserializes a byte stream looks like this: <Serializable()> _ Public Class Customer Public Function Deserialize(ByVal state As Byte()) As Customer Using m As New MemoryStream(state) Dim f As New BinaryFormatter Return CType(f.Deserialize(m), Customer) End Using End Function End Class Notice that this function returns a new customer object. It doesn t restore the existing object s state; it creates a new object. Somehow, you would have to tell any and all code that has a reference to the existing object to use this new object. In some cases, that might be easy to do, but it isn t always trivial. In complex applications, it s hard to guarantee that other code elsewhere in the application doesn t have a reference to the original object and if you don t somehow get that code to update its reference to this new object, it will continue to use the old one. What s needed is some way to restore the object s state in place, so that all references to the current object remain valid, but the object s state is restored. This is the purpose of the UndoableBase class.
Copyright © OnBarcode.com . All rights reserved.