所检查的对象。
For editors that support multi-object editing, the target property should not be used inside OnInspectorGUI since it only refers to the first of the edited objects.
This method is similar to CreateCachedEditor except that the SerializedObject is created with the context object passed as a parameter. This context object stores and retrieves the value for the ExposedReference types declared on the SerializedObject.
另请参阅：targets、serializedObject、Editor 类。