Add C# code examples (salvage of VinnNo's PRs)

tutorials/ui/gui_containers.rst

@@ -161,8 +161,8 @@ it as if it was an image (via :ref:`ViewportContainer <class_ViewportContainer>`
 Creating custom Containers
 --------------------------
 
-It is possible to easily create a custom container using script. Here is an example of a container that fits children
-to its rect size:
+It is possible to create a custom container using a script.
+Here is an example of a container that fits children to its rect size:
 
 .. tabs::
  .. code-tab:: gdscript GDScript
@@ -174,8 +174,34 @@ to its rect size:
             # Must re-sort the children
             for c in get_children():
                 # Fit to own size
-                fit_child_in_rect( c, Rect2( Vector2(), rect_size ) )
+                fit_child_in_rect(c, Rect2(Vector2(), rect_size))
 
     func set_some_setting():
-        # Some setting changed, ask for children re-sort
+        # Some setting changed, ask for children re-sort.
         queue_sort()
+
+ .. code-tab:: csharp
+
+    using Godot;
+
+    public class CustomContainer : Container
+    {
+        public override void _Notification(int what)
+        {
+            if (what == NotificationSortChildren)
+            {
+                // Must re-sort the children
+                foreach (Control c in GetChildren())
+                {
+                    // Fit to own size
+                    FitChildInRect(c, new Rect2(new Vector2(), RectSize));
+                }
+            }
+        }
+
+        public void SetSomeSetting()
+        {
+            // Some setting changed, ask for children re-sort.
+            QueueSort();
+        }
+    }

tutorials/ui/size_and_anchors.rst

@@ -63,7 +63,8 @@ To center a control in its parent, set its anchors to 0.5 and each margin
 to half of its relevant dimension. For example, the code below shows how
 a TextureRect can be centered in its parent:
 
-::
+.. tabs::
+ .. code-tab:: gdscript GDScript
 
     var rect = TextureRect.new()
     rect.texture = load("res://icon.png")
@@ -72,12 +73,30 @@ a TextureRect can be centered in its parent:
     rect.anchor_top = 0.5
     rect.anchor_bottom = 0.5
     var texture_size = rect.texture.get_size()
-    rect.margin_left = -texture_size.x / 2
-    rect.margin_right = -texture_size.x / 2
-    rect.margin_top = -texture_size.y / 2
-    rect.margin_bottom = -texture_size.y / 2
+    rect.offset_left = -texture_size.x / 2
+    rect.offset_right = texture_size.x / 2
+    rect.offset_top = -texture_size.y / 2
+    rect.offset_bottom = texture_size.y / 2
     add_child(rect)
 
+ .. code-tab:: csharp
+
+    var rect = new TextureRect();
+
+    rect.Texture = ResourceLoader.Load<Texture>("res://icon.png");
+    rect.AnchorLeft = 0.5f;
+    rect.AnchorRight = 0.5f;
+    rect.AnchorTop = 0.5f;
+    rect.AnchorBottom = 0.5f;
+
+    var textureSize = rect.Texture.GetSize();
+
+    rect.OffsetLeft = -textureSize.x / 2;
+    rect.OffsetRight = textureSize.x / 2;
+    rect.OffsetTop = -textureSize.y / 2;
+    rect.OffsetBottom = textureSize.y / 2;
+    AddChild(rect);
+
 Setting each anchor to 0.5 moves the reference point for the margins to
 the center of its parent. From there, we set negative margins so that
 the control gets its natural size.