C# Error CS0625 – ‘{0}’: instance field in types marked with StructLayout(LayoutKind.Explicit) must have a FieldOffset attribute

C# Error

CS0625 – ‘{0}’: instance field in types marked with StructLayout(LayoutKind.Explicit) must have a FieldOffset attribute

Reason for the Error & Solution

‘field’: instance field types marked with StructLayout(LayoutKind.Explicit) must have a FieldOffset attribute.

When a struct is marked with an explicit StructLayout attribute, all fields in the struct must have the attribute. For more information, see .

The following sample generates CS0625:

// CS0625.cs  
// compile with: /target:library  
using System;  
using System.Runtime.InteropServices;  
  
[StructLayout(LayoutKind.Explicit)]  
struct A  
{  
   public int i;   // CS0625 not static; an instance field  
}  
  
// OK  
[StructLayout(LayoutKind.Explicit)]  
struct B  
{  
   [FieldOffset(5)]  
   public int i;  
}