c# generate barcode from string Collections and Generics in C#

Printer QR in C# Collections and Generics

4
Quick Response Code Creation In C#
Using Barcode creation for Visual Studio .NET Control to generate, create QR image in .NET framework applications.
www.OnBarcode.com
QR Code JIS X 0510 Reader In C#
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Collections and Generics
Draw Barcode In Visual C#.NET
Using Barcode drawer for .NET Control to generate, create barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Bar Code Decoder In C#
Using Barcode reader for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
// C# coll.Insert(3, "Hey All"); string[] moreStrings = new string[] { "goodnight", "see ya" }; coll.InsertRange(4, moreStrings);
QR Code ISO/IEC18004 Maker In .NET Framework
Using Barcode printer for ASP.NET Control to generate, create QR-Code image in ASP.NET applications.
www.OnBarcode.com
Generating Denso QR Bar Code In .NET
Using Barcode maker for .NET framework Control to generate, create QR Code ISO/IEC18004 image in .NET framework applications.
www.OnBarcode.com
In addition to the Insert and Add methods, you can also use the indexer to set a specific object in the collection, as shown in the following code:
QR Code Generation In Visual Basic .NET
Using Barcode creator for .NET framework Control to generate, create QR image in Visual Studio .NET applications.
www.OnBarcode.com
Paint EAN-13 Supplement 5 In Visual C#.NET
Using Barcode encoder for Visual Studio .NET Control to generate, create European Article Number 13 image in VS .NET applications.
www.OnBarcode.com
' VB coll(3) = "Hey All" // C# Coll[3] = "Hey All";
Drawing Linear Barcode In Visual C#.NET
Using Barcode generation for VS .NET Control to generate, create Linear image in Visual Studio .NET applications.
www.OnBarcode.com
Code 128C Generation In C#.NET
Using Barcode encoder for VS .NET Control to generate, create Code 128 Code Set B image in .NET applications.
www.OnBarcode.com
Note that using the indexer is not the same as using the Insert method, as it sets the item at that specific location in the collection by overwriting the old object at that position rather than just inserting an object. Finally, the ArrayList supports removing items from the collection. Three methods support removing items: Remove, RemoveAt, and RemoveRange. The Remove method will remove a specific object from the collection. There is no indication if Remove failed to find the item to remove. In other words, if the item is not found in the collection, Remove will return without throwing an exception. The Remove method is demonstrated in the following example:
Print Bar Code In Visual C#.NET
Using Barcode maker for VS .NET Control to generate, create barcode image in .NET framework applications.
www.OnBarcode.com
International Standard Serial Number Printer In Visual C#
Using Barcode drawer for .NET Control to generate, create ISSN - 13 image in .NET applications.
www.OnBarcode.com
' VB coll.Add("Hello") coll.Remove("Hello") // C# coll.Add("Hello"); coll.Remove("Hello");
Scan Barcode In VS .NET
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
UPC-A Supplement 2 Reader In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
In contrast, the RemoveAt method removes an item at a particular index within the collection. In addition, the RemoveRange method supports removing a range of indexes from the collection all at once. Both methods are demonstrated here:
QR Recognizer In VB.NET
Using Barcode scanner for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
QR Code JIS X 0510 Maker In None
Using Barcode encoder for Software Control to generate, create QR Code 2d barcode image in Software applications.
www.OnBarcode.com
' VB ' Removes first item in ArrayList coll.RemoveAt(0) ' Removes first four items in ArrayList coll.RemoveRange(0, 4) // C# // Removes first item in ArrayList coll.RemoveAt(0); // Removes first four items in ArrayList coll.RemoveRange(0, 4);
Decode EAN / UCC - 13 In VB.NET
Using Barcode reader for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Barcode Recognizer In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Lesson 1: Collecting Data Items
EAN 13 Generation In None
Using Barcode printer for Online Control to generate, create EAN13 image in Online applications.
www.OnBarcode.com
Data Matrix Drawer In None
Using Barcode generation for Software Control to generate, create Data Matrix 2d barcode image in Software applications.
www.OnBarcode.com
The ArrayList class also supports some other methods that are useful in adding objects to and removing objects from the collection:
The Clear method is used to empty a collection of all its items. The IndexOf method is used to determine the index of a particular item in the collection. The Contains method is used to test whether a particular object exists in the collection.
By using these methods, you can perform more complex adding and removing of items within the collection, as shown in this example:
' VB Dim myString As String = "My String" If coll.Contains(myString) Then Dim index As Integer = coll.IndexOf(myString) coll.RemoveAt(index) Else coll.Clear() End If // C# string myString = "My String"; if (coll.Contains(myString)) { int index = coll.IndexOf(myString); coll.RemoveAt(index); } else { coll.Clear(); }
You can now manipulate the objects in the collection, but how do you get them out of the collection
Iterating Over Items
A collection is not very useful unless you can walk through the items in it. Luckily, the ArrayList (like most collections in this chapter) supports several ways to iterate over its contents. The ArrayList supports a numeric indexer that allows you to write simple code, such as the following, to show the items in order (much like you can with an array):
' VB Dim x As Integer For x = 0 To coll.Count - 1 Step + 1 Console.WriteLine(coll(x)) Next
4
Collections and Generics
// C# for (int x = 0; x < coll.Count; ++x) { Console.WriteLine(coll[x]); }
By using the ArrayList s Count property and indexer, you can simply walk through the collection. The ArrayList also supports the IEnumerable interface to allow the use of an Enumerator to access the list. The IEnumerable interface dictates that the class supports the GetEnumerator method that returns an IEnumerator interface. In turn, the IEnumerator interface provides a simple interface for iterating in a forward direction. Details of the IEnumerator interface can be seen in Table 4-2 (which shows properties) and 4-3 (which shows methods).
Table 4-2
IEnumerator Properties
Name Current
Table 4-3
Description Gets the current item in the collection being enumerated
IEnumerator Methods
Name MoveNext
Description Moves to the next item in the collection. The return value of the method is used to determine whether the enumerator has reached the end of the collection. Sets the enumerator to before the first item in the collection to allow MoveNext to be called to get the first item in the collection.
Reset
Using the IEnumerator interface allows you to walk through the list of objects in an ordered way, as seen in this example:
' VB Dim enumerator As IEnumerator = coll.GetEnumerator() While enumerator.MoveNext() Console.WriteLine(enumerator.Current) End While // C# IEnumerator enumerator = coll.GetEnumerator(); while (enumerator.MoveNext()) { Console.WriteLine(enumerator.Current); }
Copyright © OnBarcode.com . All rights reserved.