mono/tests/marshal10.cs

   1 // A demonstration of a custom marshaler that marshals
   2 // unmanaged to managed data.
   3
   4 using System;
   5 using System.Runtime.InteropServices;
   6
   7 public class MyMarshal: ICustomMarshaler
   8 {
   9
  10         // GetInstance() is not part of ICustomMarshaler, but
  11         // custom marshalers are required to implement this
  12         // method.
  13         public static ICustomMarshaler GetInstance (string s)
  14         {
  15                 Console.WriteLine ("GetInstance called");
  16                 return new MyMarshal ();
  17         }
  18
  19         public void CleanUpManagedData (object managedObj)
  20         {
  21                 Console.WriteLine ("CleanUpManagedData called");
  22         }
  23
  24         public void CleanUpNativeData (IntPtr pNativeData)
  25         {
  26                 Console.WriteLine("CleanUpNativeData called");
  27                 if (pNativeData != IntPtr.Zero)
  28                         Marshal.FreeHGlobal (pNativeData);
  29         }
  30
  31
  32         // I really do not understand the purpose of this method
  33         // or went it would be called. In fact, Rotor never seems
  34         // to call it.
  35         public int GetNativeDataSize ()
  36         {
  37                 Console.WriteLine("GetNativeDataSize() called");
  38                 return 4;
  39         }
  40
  41         public IntPtr MarshalManagedToNative (object managedObj)
  42         {
  43                 Console.WriteLine("MarshalManagedToNative()");
  44                 return IntPtr.Zero;
  45         }
  46
  47
  48         // Convert a pointer to unmanaged data into a System.Object.
  49         // This method simply converts the unmanaged Ansi C-string
  50         // into a System.String and surrounds it with asterisks
  51         // to differentiate it from the default marshaler.
  52         public object MarshalNativeToManaged (IntPtr pNativeData)
  53         {
  54                 Console.WriteLine("MarshalNativeToManaged()");
  55                 return "*" + Marshal.PtrToStringAnsi( pNativeData ) + "*";
  56         }
  57 }
  58
  59 public class Testing
  60 {
  61         [DllImport("libtest.so")]
  62         [return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(MyMarshal))]
  63         private static extern string functionReturningString();
  64
  65         public static int Main()
  66         {
  67                 string res = functionReturningString();
  68                 Console.WriteLine ("native string function returns {0}", res);
  69
  70                 if (res != "*ABC*")
  71                         return 1;
  72                 return 0;
  73         }
  74
  75
  76
  77 }