MonoMobile.Views.BindingExpression.GetSourceValue C# (CSharp) Method

        public virtual object GetSourceValue()
        {
            object value = null;

            if (SourceProperty != null)
            {
                value = SourceProperty.GetValue(Binding.Source);
            }

            if (value == null && _ViewProperty != null)
            {
                value = _ViewProperty.GetValue(Binding.ViewSource);
            }

            if (value != null) return value;

            return Binding.FallbackValue;
        }

		public static IBindingExpression SetBinding(IBindable target, Binding binding)
		{
			if (target == null)
				throw new ArgumentNullException("target");

			if (binding == null)
				throw new ArgumentNullException("binding");
			
			var targetProperty = binding.TargetPath;

			IBindingExpression bindingExpression = null;
			
			object dataBinding = target.DataBinding;
			object nestedTarget = dataBinding;
			var element = target as IElement;

			MemberInfo memberInfo = null;
			FieldInfo bindablePropertyInfo = null;

			if (dataBinding != null)
			{
				var name = string.Concat(targetProperty, "Property");
				bindablePropertyInfo = dataBinding.GetType().GetField(name, BindingFlags.Public | BindingFlags.Static | BindingFlags.Instance | BindingFlags.FlattenHierarchy);
				
				name = string.Concat(name, ".ControlValue");			
				memberInfo = dataBinding.GetType().GetNestedMember(ref nestedTarget, name, false);
				if (memberInfo != null)
				{
					binding.TargetPath = name;
					binding.Target = nestedTarget;
				}
			}

			var targetReady = memberInfo != null && nestedTarget != null && binding.Source != null;

			if (targetReady)
			{
				if (_BindingExpressions == null)
					_BindingExpressions = new List<IBindingExpression>();
				
				bindingExpression = GetBindingExpression(binding);

				if (bindingExpression != null)
				{
					_BindingExpressions.Remove(bindingExpression);
				}
			
				bindingExpression = new BindingExpression(binding, memberInfo, nestedTarget) { Element = element };

				_BindingExpressions.Add(bindingExpression);
					
				var vmINPC = bindingExpression.Binding.Source as INotifyPropertyChanged;
				if (vmINPC != null)
				{
					vmINPC.PropertyChanged -= HandleDataContextPropertyChanged;
					vmINPC.PropertyChanged += HandleDataContextPropertyChanged;
				}

				var viewINPC = bindingExpression.Binding.ViewSource as INotifyPropertyChanged;
				if (viewINPC != null)
				{
					viewINPC.PropertyChanged -= HandleDataContextPropertyChanged;
					viewINPC.PropertyChanged += HandleDataContextPropertyChanged;
				}
				
				var sourceValue = bindingExpression.GetSourceValue();
				 
				var sourceCollection = sourceValue as INotifyCollectionChanged;
				if (sourceCollection != null)
				{	
					SetNotificationCollectionHandler(bindingExpression, sourceCollection);
				}	
			}
			else
			{
				var binderKey =_Bindings.SingleOrDefault((kvp)=>kvp.Key.Object == target && kvp.Key.Property == targetProperty).Key;

				if (binderKey == null)
					_Bindings.Add(new PropertyBinder() { Object = target, Property = targetProperty }, binding);
				else
					_Bindings[binderKey] = binding;
			}
			
			if (bindablePropertyInfo != null)
			{
				var bindableProperty = bindablePropertyInfo.GetValue(dataBinding) as BindableProperty;
				if (bindableProperty != null)
					bindableProperty.BindingExpression = bindingExpression;
			}

			return bindingExpression;
		}