Build Page, Project Designer (C#)
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
Use the Build page of the Project Designer to specify the project's build configuration properties. This page applies to Visual C# projects only.
To access the Build page, choose a project node (not the Solution node) in Solution Explorer. Then choose View, Property Pages on the menu. When the Project Designer appears, choose the Build tab.
Note
Your computer might show different names or locations for some of the Visual Studio user interface elements in this article. You may be using a different edition of Visual Studio or different environment settings. For more information, see Personalize the IDE.
Configuration and Platform
The following options enable you to select the configuration and platform to display or modify.
Note
With simplified build configurations, the project system determines whether to build a debug or release version. Therefore, these options are not displayed. For more information, see How to: Set debug and release configurations.
Configuration
Specifies which configuration settings to display or modify. The settings can be Active (Debug) (this is the default), Debug, Release, or All Configurations.
Platform
Specifies which platform settings to display or modify. The default setting is Active (Any CPU). You can change the active platform using the Configuration Manager. For more information, see How to: Create and Edit Configurations.
General
The following options enable you to configure several C# compiler settings.
Conditional compilation symbols
Specifies symbols on which to perform conditional compilation. Separate symbols with a semi-colon (";"). For more information, see /define (C# Compiler Options).
Define DEBUG constant
Defines DEBUG as a symbol in all source code files in your app. Selecting this is equivalent to using the /define:DEBUG command-line option.
Define TRACE constant
Defines TRACE as a symbol in all source code files in your app. Selecting this is equivalent to using the /define:TRACE command-line option.
Platform Target
Specifies the processor to be targeted by the output file. Choose x86 for any 32-bit Intel-compatible processor, choose x64 for any 64-bit Intel-compatible processor, choose ARM for ARM processors, or choose Any CPU to specify that any processor is acceptable. Any CPU is the default value for projects, because it allows the application to run on the broadest range of hardware.
For more information, see /platform (C# Compiler Options).
Nullable
Specifies the project-wide C# nullable context. This UI option was introduced in Visual Studio 16.5, and is only enabled for projects that use C# 8.0 or later.
For more information, see Nullable Contexts.
Prefer 32-bit
If the Prefer32-bit check box is selected, the application runs as a 32-bit application on both 32-bit and 64-bit versions of Windows. If the check box is cleared, the application runs as a 32-bit application on 32-bit versions of Windows and as a 64-bit application on 64-bit versions of Windows.
If you run an application as a 64-bit application, the pointer size doubles, and compatibility problems can occur with other libraries that are exclusively 32-bit. It is useful to run a 64-bit application only if it needs more than 4 GB of memory or 64-bit instructions provide a significant performance improvement.
This check box is available only if all of the following conditions are true:
On the Build Page, the Platform target list is set to Any CPU.
On the Application Page, the Output type list specifies that the project is an application.
On the Application Page, the Target framework list specifies the .NET Framework 4.5.
Allow unsafe code
Allows code that uses the unsafe keyword to compile. For more information, see /unsafe (C# Compiler Options).
Optimize code
Enable or disable optimizations performed by the compiler to make your output file smaller, faster, and more efficient. For more information, see /optimize (C# Compiler Options).
Errors and Warnings
The following settings are used to configure the error and warning options for the build process.
Warning level
Specifies the level to display for compiler warnings. For more information, see /warn (C# Compiler Options).
Suppress warnings
Blocks the compiler's ability to generate one or more warnings. Separate multiple warning numbers with a comma or semicolon. For more information, see /nowarn (C# Compiler Options).
Treat Warnings as Errors
The following settings are used to specify which warnings are treated as errors. Select one of the following options to indicate under what conditions to return an error when the build encounters a warning. For more information, see /warnaserror (C# Compiler Options).
None - Treats no warnings as errors.
All - Treats all warnings as errors.
Specific warnings - Treats the specified warnings as errors. Separate multiple warning numbers with a comma or semicolon.
Tip
If you don't want code analysis warnings to be treated as errors, see Code analysis FAQ.
Output
The following settings are used to configure the output options for the build process.
Output path
Specifies the location of the output files for this project's configuration. Enter the path of the build output in this box, or choose the Browse button to specify a path. The path is relative; if you enter an absolute path, it will be saved as relative. The default path is bin\Debug or bin\Release\.
With simplified build configurations, the project system determines whether to build a debug or release version. The Build command from the Debug menu (F5) will put the build in the debug location regardless of the Output path you specify. However, the Build command from the Build menu puts it in the location you specify. For more information, see Understanding Build Configurations.
XML documentation file
Specifies the name of a file into which documentation comments will be processed. For more information, see /doc (C# Compiler Options).
Register for COM interop
Indicates that your managed application will expose a COM object (a COM callable wrapper) that allows a COM object to interact with your managed application. The Output type property in the Application page of the Project Designer for this application must be set to Class Library in order for the Register for COM interop property to be available. For an example class that you might include in your Visual C# application and expose as a COM object, see Example COM Class.
Generate serialization assembly
Specifies whether the compiler will use the XML Serializer Generator Tool (Sgen.exe) to create XML serialization assemblies. Serialization assemblies can improve the startup performance of XmlSerializer if you have used that class to serialize types in your code. By default, this option is set to Auto, which specifies that serialization assemblies be generated only if you have used XmlSerializer to encode types in your code to XML. Off specifies that serialization assemblies never be generated, regardless of whether your code uses XmlSerializer. On specifies that serialization assemblies always be generated. Serialization assemblies are named TypeName.XmlSerializers.dll. For more information, see XML Serializer Generator Tool (Sgen.exe).
Advanced
Click to display the Advanced Build Settings Dialog Box (C#) dialog box.