See Also: BrowsableAttribute Members
A visual designer typically displays in the Properties window those members that either have no browsable attribute or are marked with the BrowsableAttribute.#ctor(bool) constructor's browsable parameter set to true. These members can be modified at design time. Members marked with the BrowsableAttribute.#ctor(bool) constructor's browsable parameter set to false are not appropriate for design-time editing and therefore are not displayed in a visual designer. The default is true.
When you mark a property with Browsable(true), the value of this attribute is set to the constant member BrowsableAttribute.Yes. For a property marked with Browsable(false), the value is BrowsableAttribute.No. Therefore, when you check the value of this attribute in your code, you must specify the attribute as BrowsableAttribute.Yes or BrowsableAttribute.No.
For more information, see Extending Metadata Using Attributes.