Specifies which version of the common language runtime (CLR) can run the assembly.
/platform:string
Parameters
- string
 anycpu (default), anycpu32bitpreferred, ARM, x64, x86, or Itanium.
Remarks
- anycpu (default) compiles your assembly to run on any platform. Your application runs as a 64-bit process whenever possible and falls back to 32-bit when only that mode is available. 
- anycpu32bitpreferred compiles your assembly to run on any platform. Your application runs in 32-bit mode on systems that support both 64-bit and 32-bit applications. You can specify this option only for projects that target the .NET Framework 4.5. 
- ARM compiles your assembly to run on a computer that has an Advanced RISC Machine (ARM) processor. 
- x64 compiles your assembly to be run by the 64-bit common language runtime on a computer that supports the AMD64 or EM64T instruction set. 
- x86 compiles your assembly to be run by the 32-bit, x86-compatible common language runtime. 
- Itanium compiles your assembly to be run by the 64-bit common language runtime on a computer with an Itanium processor. 
On a 64-bit Windows operating system:
- Assemblies compiled with /platform:x86 execute on the 32-bit CLR running under WOW64. 
- A DLL compiled with the /platform:anycpu executes on the same CLR as the process into which it is loaded. 
- Executables that are compiled with the /platform:anycpu execute on the 64-bit CLR. 
- Executables compiled with /platform:anycpu32bitpreferred execute on the 32-bit CLR. 
The anycpu32bitpreferred setting is valid only for executable (.EXE) files, and it requires the .NET Framework 4.5.
For more information about developing an application to run on a Windows 64-bit operating system, see 64-bit Applications.
To set this compiler option in the Visual Studio development environment
- Open the Properties page for the project. 
- Click the Build property page. 
- Modify the Platform target property and, for projects that target the .NET Framework 4.5, select or clear the Prefer 32-bit check box. 
Note /platform is not available in the development environment in Visual C# Express.
For information on how to set this compiler option programmatically, see PlatformTarget.
Example
The following example shows how to use the /platform option to specify that the application should be run by the 64-bit CLR on a 64-bit Windows operating system.
csc /platform:anycpu filename.cs
See Also
Tasks
How to: Modify Project Properties and Configuration Settings