Replace GCHandle.Alloc with fixed statements (#274)

Author: Marioalexsan

src/SFML.Audio/Music.cs

@@ -74,15 +74,14 @@ public Music(Stream stream) :
         public Music(byte[] bytes) :
             base(IntPtr.Zero)
         {
-            var pin = GCHandle.Alloc(bytes, GCHandleType.Pinned);
-            try
+            unsafe
             {
-                CPointer = sfMusic_createFromMemory(pin.AddrOfPinnedObject(), (UIntPtr)bytes.Length);
-            }
-            finally
-            {
-                pin.Free();
+                fixed (void* ptr = bytes)
+                {
+                    CPointer = sfMusic_createFromMemory((IntPtr)ptr, (UIntPtr)bytes.Length);
+                }
             }
+
             if (IsInvalid)
             {
                 throw new LoadingFailedException("music");

src/SFML.Audio/SoundBuffer.cs

@@ -72,15 +72,14 @@ public SoundBuffer(Stream stream) :
         public SoundBuffer(byte[] bytes) :
             base(IntPtr.Zero)
         {
-            var pin = GCHandle.Alloc(bytes, GCHandleType.Pinned);
-            try
-            {
-                CPointer = sfSoundBuffer_createFromMemory(pin.AddrOfPinnedObject(), (UIntPtr)bytes.Length);
-            }
-            finally
+            unsafe
             {
-                pin.Free();
+                fixed (void* ptr = bytes)
+                {
+                    CPointer = sfSoundBuffer_createFromMemory((IntPtr)ptr, (UIntPtr)bytes.Length);
+                }
             }
+
             if (IsInvalid)
             {
                 throw new LoadingFailedException("sound buffer");

src/SFML.Graphics/Font.cs

@@ -62,15 +62,14 @@ public Font(Stream stream) : base(IntPtr.Zero)
         public Font(byte[] bytes) :
             base(IntPtr.Zero)
         {
-            var pin = GCHandle.Alloc(bytes, GCHandleType.Pinned);
-            try
+            unsafe
             {
-                CPointer = sfFont_createFromMemory(pin.AddrOfPinnedObject(), (UIntPtr)bytes.Length);
-            }
-            finally
-            {
-                pin.Free();
+                fixed (void* ptr = bytes)
+                {
+                    CPointer = sfFont_createFromMemory((IntPtr)ptr, (UIntPtr)bytes.Length);
+                }
             }
+
             if (IsInvalid)
             {
                 throw new LoadingFailedException("font");

src/SFML.Graphics/Image.cs

@@ -87,15 +87,14 @@ public Image(Stream stream) :
         public Image(byte[] bytes) :
             base(IntPtr.Zero)
         {
-            var pin = GCHandle.Alloc(bytes, GCHandleType.Pinned);
-            try
-            {
-                CPointer = sfImage_createFromMemory(pin.AddrOfPinnedObject(), (UIntPtr)bytes.Length);
-            }
-            finally
+            unsafe
             {
-                pin.Free();
+                fixed (void* ptr = bytes)
+                {
+                    CPointer = sfImage_createFromMemory((IntPtr)ptr, (UIntPtr)bytes.Length);
+                }
             }
+
             if (IsInvalid)
             {
                 throw new LoadingFailedException("image");

src/SFML.Graphics/Texture.cs

@@ -205,21 +205,19 @@ public Texture(byte[] bytes, bool srgb = false) :
         public Texture(byte[] bytes, IntRect area, bool srgb = false) :
             base(IntPtr.Zero)
         {
-            var pin = GCHandle.Alloc(bytes, GCHandleType.Pinned);
-            try
+            unsafe
             {
-                if (srgb)
+                fixed (void* ptr = bytes)
                 {
-                    CPointer = sfTexture_createSrgbFromMemory(pin.AddrOfPinnedObject(), (UIntPtr)bytes.Length, ref area);
+                    if (srgb)
+                    {
+                        CPointer = sfTexture_createSrgbFromMemory((IntPtr)ptr, (UIntPtr)bytes.Length, ref area);
+                    }
+                    else
+                    {
+                        CPointer = sfTexture_createFromMemory((IntPtr)ptr, (UIntPtr)bytes.Length, ref area);
+                    }
                 }
-                else
-                {
-                    CPointer = sfTexture_createFromMemory(pin.AddrOfPinnedObject(), (UIntPtr)bytes.Length, ref area);
-                }
-            }
-            finally
-            {
-                pin.Free();
             }
 
             if (IsInvalid)