CIL Code in C#

Encoder PDF-417 2d barcode in C# CIL Code
CIL Code
PDF417 Drawer In Visual C#
Using Barcode creation for .NET framework Control to generate, create PDF-417 2d barcode image in .NET applications.
method private hidebysig static void Main() cil managed { entrypoint // Code size 21 (0x15) maxstack 1 locals init ([0] int32 number, [1] object thing) IL_0000: nop IL_0001: ldci4s 42 IL_0003: stloc0 IL_0004: ldloc0 IL_0005: box [mscorlib]SystemInt32 IL_000a: stloc1 IL_000b: ldloc1 IL_000c: unboxany [mscorlib]SystemInt32 IL_0011: stloc0 IL_0012: brs IL_0014 IL_0014: ret } // end of method Program::Main
Generate Barcode In Visual C#.NET
Using Barcode generator for Visual Studio .NET Control to generate, create bar code image in .NET framework applications.
int number; object thing; number = 42; // Boxing thing = number; // Unboxing number = (int)thing;
Encoding PDF417 In VS .NET
Using Barcode maker for ASP.NET Control to generate, create PDF-417 2d barcode image in ASP.NET applications.
return; }
PDF-417 2d Barcode Creation In .NET Framework
Using Barcode creator for Visual Studio .NET Control to generate, create PDF-417 2d barcode image in .NET applications.
Listing 85: Subtle Box and Unbox Instructions
Drawing PDF 417 In Visual Basic .NET
Using Barcode encoder for VS .NET Control to generate, create PDF417 image in .NET applications.
class DisplayFibonacci { static void Main() { int totalCount; SystemCollectionsArrayList list = new SystemCollectionsArrayList(); ConsoleWrite("Enter a number between 2 and 1000:"); totalCount = intParse(ConsoleReadLine()); // Execution-time error: // listAdd(0); // Cast to double or 'D' suffix required // Whether cast or using 'D' suffix, // CIL is identical listAdd((double)0); listAdd((double)1); for (int count = 2; count < totalCount; count++) { listAdd( ((double)list[count - 1] +
Bar Code Creation In Visual C#.NET
Using Barcode printer for .NET Control to generate, create barcode image in .NET applications.
Boxing
Drawing Bar Code In C#.NET
Using Barcode printer for Visual Studio .NET Control to generate, create bar code image in .NET applications.
(double)list[count - 2]) ); } foreach (double count in list) { ConsoleWrite("{0}, ", count); } } }
USS Code 39 Printer In Visual C#.NET
Using Barcode maker for VS .NET Control to generate, create Code 39 image in Visual Studio .NET applications.
OUTPUT 81:
Encoding Code 128 Code Set C In C#.NET
Using Barcode printer for .NET Control to generate, create Code 128 image in .NET framework applications.
Enter a number between 2 and 1000:42 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229, 832040, 1346269, 2178309, 3524578, 5702887, 9227465, 14930352, 24157817, 39088169, 63245986, 102334155, 165580141,
Painting Data Matrix In Visual C#
Using Barcode generator for .NET framework Control to generate, create Data Matrix 2d barcode image in .NET applications.
The code shown in Listing 85, when compiled, produces five box and three unbox instructions in the resultant CIL 1 The first two box instructions occur in the initial calls to listAdd() The signature for the ArrayList method is int Add(object value) As such, any value type passed to this method is boxed 2 Next are two unbox instructions in the call to Add() within the for loop The return from an ArrayList s index operator is always object because that is what ArrayList collects In order to add the two values, however, you need to cast them back to doubles This cast back from an object to a value type is an unbox call 3 Now you take the result of the addition and place it into the ArrayList instance, which again results in a box operation Note that the first two unbox instructions and this box instruction occur within a loop 4 In the foreach loop, you iterate through each item in ArrayList and assign them to count However, as you already saw, the items within ArrayList are objects, so assigning them to a double is unboxing each of them 5 The signature for ConsoleWriteLine() that is called within the foreach loop is void ConsoleWrite(string format, object arg) As a result, each call to it invokes a box operation back from double and into object
EAN13 Generator In .NET
Using Barcode creator for Visual Studio .NET Control to generate, create EAN-13 image in .NET applications.
8: Value Types
Paint Code 39 Extended In Java
Using Barcode generator for Java Control to generate, create Code 39 Full ASCII image in Java applications.
Obviously, you can easily improve this code by eliminating many of the boxing operations Using an object rather than double in the last foreach loop is one improvement you can make Another would be to change the ArrayList data type to one that supports a concept known as generics (see 11) The point, however, is that boxing can be subtle, so developers need to pay special attention and notice situations where it could potentially occur repeatedly and affect performance There is another unfortunate runtime-boxing-related problem If you wanted to change the initial two Add() calls so they did not use a cast (or a double literal), you would have to insert integers into the array list Since ints will implicitly cast to doubles, this would appear to be an innocuous modification However, the casts to double from within the for loop, and again in the assignment to count in the foreach loops, would fail The problem is that immediately following the unbox operation is an attempt to perform a memory copy of the int into a double You cannot do this without first casting to an int, because the code will throw an InvalidCastException at execution time Listing 86 shows a similar error commented out and followed by the correct cast
UPC-A Supplement 5 Reader In VS .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in .NET framework applications.
Data Matrix ECC200 Printer In Java
Using Barcode creation for Java Control to generate, create ECC200 image in Java applications.
Bar Code Generation In Visual Studio .NET
Using Barcode printer for .NET Control to generate, create barcode image in .NET applications.
Print Code 128B In Visual Basic .NET
Using Barcode generation for .NET Control to generate, create Code 128A image in .NET framework applications.
Code 128 Code Set A Decoder In .NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET framework applications.