C# XamlType.IsContentValue方法代码示例

		public override void WriteStartObject (XamlType xamlType)
		{
			if (xamlType == null)
				throw new ArgumentNullException ("xamlType");

			manager.StartObject ();

			var xm = members.Count > 0 ? members.Peek () : null;
			var pstate = xm != null ? object_states.Peek () : null;
			var wpl = xm != null && xm != XamlLanguage.Items ? pstate.WrittenProperties : null;
			if (wpl != null && wpl.Contains (xm))
				throw new XamlDuplicateMemberException (String.Format ("Property '{0}' is already set to this '{1}' object", xm, pstate.Type));

			var cstate = new ObjectState () {Type = xamlType, IsInstantiated = false};
			object_states.Push (cstate);

			if (!xamlType.IsContentValue ()) // FIXME: there could be more conditions e.g. the type requires Arguments.
				InitializeObjectIfRequired (true);
			
			if (wpl != null) // note that this adds to the *owner* object's properties.
				wpl.Add (xm);
		}

		// It expects that it is not invoked when there is no value to 
		// assign.
		// When it is passed null, then it returns a default instance.
		// For example, passing null as Int32 results in 0.
		// But do not immediately try to instantiate with the type, since the type might be abstract.
		object DoGetCorrectlyTypedValue (XamlMember xm, XamlType xt, object value)
		{
			if (value == null) {
				if (xt.IsContentValue (service_provider)) // it is for collection/dictionary key and item
					return null;
				else
					return xt.IsNullable ? null : xt.Invoker.CreateInstance (new object [0]);
			}
			if (xt == null)
				return value;

			// Not sure if this is really required though...
			var vt = sctx.GetXamlType (value.GetType ());
			if (vt.CanAssignTo (xt))
				return value;

			// FIXME: this could be generalized by some means, but I cannot find any.
			if (xt.UnderlyingType == typeof (XamlType) && value is string)
				value = ResolveTypeFromName ((string) value);

			// FIXME: this could be generalized by some means, but I cannot find any.
			if (xt.UnderlyingType == typeof (Type))
				value = new TypeExtension ((string) value).ProvideValue (service_provider);
			if (xt == XamlLanguage.Type && value is string)
				value = new TypeExtension ((string) value);
			
			if (IsAllowedType (xt, value))
				return value;

			var xtc = xm?.TypeConverter ?? xt.TypeConverter;
			if (xtc != null && value != null) {
				var tc = xtc.ConverterInstance;
				if (tc != null && tc.CanConvertFrom (value.GetType ()))
					value = tc.ConvertFrom (service_provider, null, value);
				return value;
			}

			throw new XamlObjectWriterException (String.Format ("Value '{0}' (of type {1}) is not of or convertible to type {0} (member {3})", value, value != null ? (object) value.GetType () : "(null)", xt, xm));
		}

		public override void WriteStartObject (XamlType xamlType)
		{
			if (xamlType == null)
				throw new ArgumentNullException ("xamlType");

			manager.StartObject ();

			var xm = members.Count > 0 ? members.Peek () : null;
			var pstate = xm != null ? object_states.Peek () : null;
			var wpl = xm == null || xm.Type.IsCollection || xm.Type.IsDictionary ? null : pstate.WrittenProperties;
			if (wpl != null && wpl.Contains (xm))
				throw new XamlDuplicateMemberException (String.Format ("Property '{0}' is already set to this '{1}' object", xm, pstate.Type));

			var cstate = new ObjectState () {Type = xamlType, IsInstantiated = false};
			object_states.Push (cstate);

			if (!xamlType.IsContentValue (service_provider))
				InitializeObjectIfRequired (true);
			
			if (wpl != null) // note that this adds to the *owner* object's properties.
				wpl.Add (xm);
		}