barcode printing vb.net Part IV in C#

Encoder PDF 417 in C# Part IV

Part IV
Generating PDF417 In Visual C#
Using Barcode creator for .NET Control to generate, create PDF 417 image in .NET applications.
www.OnBarcode.com
Decode PDF417 In Visual C#
Using Barcode scanner for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Core Facilities
Barcode Generation In Visual C#.NET
Using Barcode generator for .NET Control to generate, create barcode image in .NET framework applications.
www.OnBarcode.com
Read Barcode In Visual C#
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Because the FileStream class also offers a public Close method, the earlier code could be written as follows with identical results:
PDF 417 Generator In .NET Framework
Using Barcode generator for ASP.NET Control to generate, create PDF417 image in ASP.NET applications.
www.OnBarcode.com
PDF417 Drawer In .NET
Using Barcode drawer for .NET Control to generate, create PDF417 image in VS .NET applications.
www.OnBarcode.com
using System; using System.IO; public static class Program { public static void Main() { // Create the bytes to write to the temporary file. Byte[] bytesToWrite = new Byte[] { 1, 2, 3, 4, 5 }; // Create the temporary file. FileStream fs = new FileStream("Temp.dat", FileMode.Create); // Write the bytes to the temporary file. fs.Write(bytesToWrite, 0, bytesToWrite.Length); // Explicitly close the file when finished writing to it. fs.Close(); // Delete the temporary file. File.Delete("Temp.dat"); // This always works now. } }
PDF417 Generator In Visual Basic .NET
Using Barcode maker for VS .NET Control to generate, create PDF 417 image in Visual Studio .NET applications.
www.OnBarcode.com
Code39 Generator In C#.NET
Using Barcode creation for VS .NET Control to generate, create Code39 image in Visual Studio .NET applications.
www.OnBarcode.com
Note Again, remember that the Close method isn t officially part of the dispose pattern; some
Print Universal Product Code Version A In C#
Using Barcode creator for .NET framework Control to generate, create Universal Product Code version A image in VS .NET applications.
www.OnBarcode.com
Matrix Barcode Generator In Visual C#
Using Barcode generation for VS .NET Control to generate, create 2D Barcode image in VS .NET applications.
www.OnBarcode.com
types will offer it and some won t .
Generating Code 128 Code Set B In C#
Using Barcode encoder for .NET Control to generate, create USS Code 128 image in .NET applications.
www.OnBarcode.com
Draw GTIN - 12 In Visual C#.NET
Using Barcode drawer for Visual Studio .NET Control to generate, create UPCE image in Visual Studio .NET applications.
www.OnBarcode.com
Keep in mind that calling Dispose or Close simply gives the programmer a way to force the object to do its cleanup at a deterministic time; these methods have no control over the lifetime of the memory used by the object in the managed heap . This means you can still call methods on the object even though it has been cleaned up . The following code calls the Write method after the file is closed, attempting to write more bytes to the file . Obviously, the bytes can t be written, and when the code executes, the second call to the Write method throws a System.ObjectDisposedException exception with the following string message:
Make GS1 - 13 In Java
Using Barcode drawer for Java Control to generate, create European Article Number 13 image in Java applications.
www.OnBarcode.com
PDF-417 2d Barcode Creator In VB.NET
Using Barcode maker for Visual Studio .NET Control to generate, create PDF417 image in .NET framework applications.
www.OnBarcode.com
"Cannot access a closed file."
Code 128 Code Set B Encoder In None
Using Barcode creation for Word Control to generate, create Code 128 Code Set B image in Office Word applications.
www.OnBarcode.com
Decode EAN 13 In .NET
Using Barcode reader for .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
using System; using System.IO; public static class Program { public static void Main() { // Create the bytes to write to the temporary file. Byte[] bytesToWrite = new Byte[] { 1, 2, 3, 4, 5 }; // Create the temporary file. FileStream fs = new FileStream("Temp.dat", FileMode.Create); // Write the bytes to the temporary file.
Scan Code 3/9 In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Linear 1D Barcode Printer In Visual Basic .NET
Using Barcode generation for Visual Studio .NET Control to generate, create Linear Barcode image in .NET framework applications.
www.OnBarcode.com
21
Barcode Reader In Java
Using Barcode Control SDK for BIRT reports Control to generate, create, read, scan barcode image in Eclipse BIRT applications.
www.OnBarcode.com
EAN / UCC - 13 Drawer In None
Using Barcode drawer for Online Control to generate, create EAN128 image in Online applications.
www.OnBarcode.com
Automatic Memory Management (Garbage Collection)
fs.Write(bytesToWrite, 0, bytesToWrite.Length); // Explicitly close the file when finished writing to it. fs.Close(); // Try to write to the file after closing it. // The following line throws an ObjectDisposedException. fs.Write(bytesToWrite, 0, bytesToWrite.Length); // Delete the temporary file. File.Delete("Temp.dat"); } }
No memory corruption has occurred here because the memory for the FileStream object still exists; it s just that the object can t successfully execute its methods after it is explicitly disposed . Important When defining your own type that implements the dispose pattern, be sure to write
code in all of your methods and properties to throw a System.ObjectDisposedException if the object has been explicitly cleaned up . The Dispose and Close methods should never throw an ObjectDisposedException if called multiple times, though; these methods should just return .
Important In general, I strongly discourage calling a Dispose or Close method . The reason is
that the CLR s garbage collector is well written, and you should let it do its job . The garbage collector knows when an object is no longer accessible from application code, and only then will it collect the object . When application code calls Dispose or Close, it is effectively saying that it knows when the application no longer has a need for the object . For many applications, it is impossible to know for sure when an object is no longer required . For example, if you have code that constructs a new object, and you then pass a reference to this object to another method, the other method could save a reference to the object in some internal field variable (a root) . There is no way for the calling method to know that this has happened . Sure, the calling method can call Dispose or Close, but later, some other code might try to access the object, causing an ObjectDisposedException to be thrown . I recommend that you call Dispose or Close either at a place in your code where you know you must clean up the resource (as in the case of attempting to delete an open file) or at a place where you know it is safe to call one of the methods and you want to improve performance by removing the object from the finalization list, thus preventing object promotion .
Copyright © OnBarcode.com . All rights reserved.