c# data matrix barcode generator Compilation Model in C#.NET

Generating Data Matrix 2d barcode in C#.NET Compilation Model

Compilation Model
Print DataMatrix In Visual C#.NET
Using Barcode generation for .NET Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Data Matrix 2d Barcode Recognizer In C#.NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Native
Code 3 Of 9 Maker In Visual C#
Using Barcode printer for .NET framework Control to generate, create Code 3/9 image in Visual Studio .NET applications.
www.OnBarcode.com
Make PDF417 In Visual C#
Using Barcode creator for .NET framework Control to generate, create PDF-417 2d barcode image in Visual Studio .NET applications.
www.OnBarcode.com
__cplusplus_cli
Make Barcode In C#
Using Barcode creator for .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Make QR Code JIS X 0510 In Visual C#
Using Barcode drawer for .NET framework Control to generate, create Denso QR Bar Code image in .NET applications.
www.OnBarcode.com
Not defined 200406 200406 200406
Paint Barcode In Visual C#
Using Barcode printer for Visual Studio .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Making MSI Plessey In C#.NET
Using Barcode printer for VS .NET Control to generate, create MSI Plessey image in .NET applications.
www.OnBarcode.com
_M_CEE
Creating ECC200 In None
Using Barcode creation for Word Control to generate, create Data Matrix ECC200 image in Office Word applications.
www.OnBarcode.com
Data Matrix Recognizer In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Not defined 1 1 1 1
Encode UPC A In .NET Framework
Using Barcode generator for Visual Studio .NET Control to generate, create UPC-A Supplement 5 image in .NET applications.
www.OnBarcode.com
PDF-417 2d Barcode Printer In VS .NET
Using Barcode generation for VS .NET Control to generate, create PDF 417 image in .NET framework applications.
www.OnBarcode.com
_M_CEE_PURE
Data Matrix Creator In None
Using Barcode drawer for Online Control to generate, create Data Matrix image in Online applications.
www.OnBarcode.com
PDF417 Scanner In Visual Studio .NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Not defined Not defined 1 1 Not defined
Generating PDF417 In Java
Using Barcode maker for BIRT Control to generate, create PDF-417 2d barcode image in Eclipse BIRT applications.
www.OnBarcode.com
Code39 Generator In Java
Using Barcode creation for BIRT Control to generate, create Code39 image in BIRT reports applications.
www.OnBarcode.com
_M_CEE_SAFE
Data Matrix ECC200 Generation In None
Using Barcode encoder for Software Control to generate, create Data Matrix ECC200 image in Software applications.
www.OnBarcode.com
ECC200 Drawer In Java
Using Barcode printer for Android Control to generate, create Data Matrix ECC200 image in Android applications.
www.OnBarcode.com
Not defined Not defined Not defined 1 Not defined
Make GS1 - 13 In VS .NET
Using Barcode drawer for .NET framework Control to generate, create GTIN - 13 image in Visual Studio .NET applications.
www.OnBarcode.com
Painting QR In Java
Using Barcode generation for Java Control to generate, create QR Code ISO/IEC18004 image in Java applications.
www.OnBarcode.com
_MANAGED
Not defined 1 1 1 1
/clr /clr:pure /clr:safe
/clr:oldsyntax Not defined
As the following sample shows, checking the different compilation models using these macros is possible however, not in an elegant way: #ifndef _MANAGED #pragma message("Native compilation model chosen") #endif #if (defined(_M_CEE) && !defined(_M_CEE_PURE) && !defined(_M_CEE_SAFE)) #pragma message("compiling with /clr") #endif #if (defined(_M_CEE) && defined(_M_CEE_PURE) && !defined(_M_CEE_SAFE)) #pragma message("compiling with /clr:pure") #endif #ifdef _M_CEE_SAFE #pragma message("compiling with /clr:safe") #endif
Compilation Models and Templates
C++ templates require special attention in mixed-code projects. Templates are typically defined in header files. Before you can use a template type, you have to include the header defining the template type and its members. When a template is used in a file that is compiled to native code, the member functions of the template type are compiled to native code, too. When a source file using a template is compiled to managed code, the template s members are compiled to managed code. When two source files in your project use the same template and both are compiled with different compilation models, the linker will get two variants of the template s functions: one compiled to managed code and one compiled to native code. In this case, it is up to the linker to decide which version should be chosen. To avoid unnecessary method calls across managed-unmanaged boundaries, the linker chooses the native variant of a function if the caller is a native function, and the managed variant if the caller is a managed function. This means that you will likely have both variants of the function in your DLL or EXE file. Sometimes it is argued that #pragma unmanaged should be used to ensure that a template is compiled to native code even though it is called from managed code. As mentioned before,
CHAPTER 7 USING C++/CLI TO EXTEND VISUAL C++ PROJECTS WITH MANAGED CODE
#pragma unmanaged is not recommended. In the context of templates, they are often even more misleading. The following code shows a typical attempt to compile a template to native code even though it is used by managed code: // templatesAndPragmaUnmanaged.cpp // build with: cl /clr templatesAndPragmaUnmanaged.cpp #pragma managed (push, off) #include <vector> #pragma managed (pop) using namespace std; int main() { vector<int> vi; vi.push_back(5); } If you build this application, members of the template std::vector such as the push_back function will be compiled to native code. However, if there is a second source file in the project that compiles vector<int>::push_back to managed code, the linker will choose the managed variant instead of the native one when it generates the code for main. Even though you have included the vector in a native section of your source file, the managed variant will be chosen. If you want to ensure that a template is compiled to native code, make sure that you call it from a source file compiled to native code.
Summary
Before you start migrating a native project so that you can extend it with managed types, you should consider what impacts this has. Using managed constructs in your project implies that your code depends on the CLR 2.0 at runtime and that the managed code parts are executed under the CLR s control. All services of the CLR can be beneficial if you know how to use them, but if you are not aware of these services, they can also imply pitfalls. For example, CAS may prevent you from running your code via a network share. In most cases, these pitfalls can be avoided (e.g., by modifying the .NET security configuration). Once you have finished these up-front considerations, you should follow the step-by-step instructions described in this chapter to migrate the project. Testing is an essential part of this migration because it allows you to detect scenarios that you have not considered up front. Once the project is migrated, C++/CLI s interoperability features allow you to call managed functions from native functions and vice versa. The functions used so far have had void as a return type, and no arguments. The next chapter covers how and why you can also use complex native types at the migration boundary.
Copyright © OnBarcode.com . All rights reserved.