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public static GetAttributes ( |
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| componentType | ||
| Результат | ||
/// <summary>
/// Retrieves custom attributes.
/// </summary>
internal AttributeCollection GetAttributes()
{
// Worst case collision scenario: we don't want the perf hit
// of taking a lock, so if we collide we will query for
// attributes twice. Not a big deal.
if (_attributes == null)
{
// Obtaining attributes follows a very critical order: we must take care that
// we merge attributes the right way. Consider this:
//
// [A4]
// interface IBase;
//
// [A3]
// interface IDerived;
//
// [A2]
// class Base : IBase;
//
// [A1]
// class Derived : Base, IDerived
//
// Calling GetAttributes on type Derived must merge attributes in the following
// order: A1 - A4. Interfaces always lose to types, and interfaces and types
// must be merged in the same order. At the same time, we must be careful
// that we don't always go through reflection here, because someone could have
// created a custom provider for a type. Because there is only one instance
// of ReflectTypeDescriptionProvider created for typeof(object), if our code
// is invoked here we can be sure that there is no custom provider for
// _type all the way up the base class chain.
// We cannot be sure that there is no custom provider for
// interfaces that _type implements, however, because they are not derived
// from _type. So, for interfaces, we must go through TypeDescriptor
// again to get the interfaces attributes.
// Get the type's attributes. This does not recurse up the base class chain.
// We append base class attributes to this array so when walking we will
// walk from Length - 1 to zero.
//
Attribute[] attrArray = ReflectGetAttributes(_type);
Type baseType = _type.BaseType;
while (baseType != null && baseType != typeof(object))
{
Attribute[] baseArray = ReflectGetAttributes(baseType);
Attribute[] temp = new Attribute[attrArray.Length + baseArray.Length];
Array.Copy(attrArray, temp, attrArray.Length);
Array.Copy(baseArray, 0, temp, attrArray.Length, baseArray.Length);
attrArray = temp;
baseType = baseType.BaseType;
}
// Next, walk the type's interfaces. We append these to
// the attribute array as well.
int ifaceStartIdx = attrArray.Length;
Type[] interfaces = _type.GetInterfaces();
for (int idx = 0; idx < interfaces.Length; idx++)
{
Type iface = interfaces[idx];
// Only do this for public interfaces.
if ((iface.Attributes & (TypeAttributes.Public | TypeAttributes.NestedPublic)) != 0)
{
// No need to pass an instance into GetTypeDescriptor here because, if someone provided a custom
// provider based on object, it already would have hit.
AttributeCollection ifaceAttrs = TypeDescriptor.GetAttributes(iface);
if (ifaceAttrs.Count > 0)
{
Attribute[] temp = new Attribute[attrArray.Length + ifaceAttrs.Count];
Array.Copy(attrArray, temp, attrArray.Length);
ifaceAttrs.CopyTo(temp, attrArray.Length);
attrArray = temp;
}
}
}
// Finally, put all these attributes in a dictionary and filter out the duplicates.
OrderedDictionary attrDictionary = new OrderedDictionary(attrArray.Length);
for (int idx = 0; idx < attrArray.Length; idx++)
{
bool addAttr = true;
if (idx >= ifaceStartIdx)
{
for (int ifaceSkipIdx = 0; ifaceSkipIdx < s_skipInterfaceAttributeList.Length; ifaceSkipIdx++)
{
if (s_skipInterfaceAttributeList[ifaceSkipIdx].IsInstanceOfType(attrArray[idx]))
{
addAttr = false;
break;
}
}
}
if (addAttr && !attrDictionary.Contains(attrArray[idx].TypeId))
{
attrDictionary[attrArray[idx].TypeId] = attrArray[idx];
}
}
attrArray = new Attribute[attrDictionary.Count];
attrDictionary.Values.CopyTo(attrArray, 0);
_attributes = new AttributeCollection(attrArray);
}
return(_attributes);
}
public AttributeCollection GetAttributes() => NativeTypeDesc.GetAttributes(_entityType, true);
/// <summary>
/// Retrieves the editor for the given base type.
/// </summary>
internal object GetEditor(object instance, Type editorBaseType)
{
EditorAttribute typeAttr;
// For instances, the design time object for them may want to redefine the
// attributes. So, we search the attribute here based on the instance. If found,
// we then search on the same attribute based on type. If the two don't match, then
// we cannot cache the value and must re-create every time. It is rare for a designer
// to override these attributes, so we want to be smart here.
if (instance != null)
{
typeAttr = GetEditorAttribute(TypeDescriptor.GetAttributes(_type), editorBaseType);
EditorAttribute instanceAttr = GetEditorAttribute(TypeDescriptor.GetAttributes(instance), editorBaseType);
if (typeAttr != instanceAttr)
{
Type editorType = GetTypeFromName(instanceAttr.EditorTypeName);
if (editorType != null && editorBaseType.IsAssignableFrom(editorType))
{
return(CreateInstance(editorType, _type));
}
}
}
// If we got here, we return our type-based editor.
lock (this)
{
for (int idx = 0; idx < _editorCount; idx++)
{
if (_editorTypes[idx] == editorBaseType)
{
return(_editors[idx]);
}
}
}
// Editor is not cached yet. Look in the attributes.
object editor = null;
typeAttr = GetEditorAttribute(TypeDescriptor.GetAttributes(_type), editorBaseType);
if (typeAttr != null)
{
Type editorType = GetTypeFromName(typeAttr.EditorTypeName);
if (editorType != null && editorBaseType.IsAssignableFrom(editorType))
{
editor = CreateInstance(editorType, _type);
}
}
// Editor is not in the attributes. Search intrinsic tables.
if (editor == null)
{
Hashtable intrinsicEditors = GetEditorTable(editorBaseType);
if (intrinsicEditors != null)
{
editor = SearchIntrinsicTable(intrinsicEditors, _type);
}
// As a quick sanity check, check to see that the editor we got back is of
// the correct type.
if (editor != null && !editorBaseType.IsInstanceOfType(editor))
{
Debug.Fail($"Editor {editor.GetType().FullName} is not an instance of {editorBaseType.FullName} but it is in that base types table.");
editor = null;
}
}
if (editor != null)
{
lock (this)
{
if (_editorTypes == null || _editorTypes.Length == _editorCount)
{
int newLength = (_editorTypes == null ? 4 : _editorTypes.Length * 2);
Type[] newTypes = new Type[newLength];
object[] newEditors = new object[newLength];
if (_editorTypes != null)
{
_editorTypes.CopyTo(newTypes, 0);
_editors.CopyTo(newEditors, 0);
}
_editorTypes = newTypes;
_editors = newEditors;
_editorTypes[_editorCount] = editorBaseType;
_editors[_editorCount++] = editor;
}
}
}
return(editor);
}
