Книга: Beginning Android
Step #3: Declare the Properties
Step #3: Declare the Properties
Remember those properties you referenced when you were using a content provider in the previous chapter? Well, you need to have those too for your own content provider.
Specifically, you want a public static class implementing BaseColumns that contains your property names, such as this example from Provider:
public static final class Constants implements BaseColumns {
public static final Uri CONTENT_URI =
Uri.parse("content://com.commonsware.android.constants.Provider/constants");
public static final String DEFAULT_SORT_ORDER = "title";
public static final String TITLE = "title";
public static final String VALUE = "value";
}
If you are using SQLite as a data store, the values for the property name constants should be the corresponding column name in the table, so you can just pass the projection (array of properties) to SQLite on a query(), or pass the ContentValues on an insert() or update().
Note that nothing in here stipulates the types of the properties. They could be strings, integers, or whatever. The biggest limitation is what a Cursor can provide access to via its property getters. The fact that there is nothing in code that enforces type safety means you should document the property types well so people attempting to use your content provider know what they can expect.
Оглавление книги
- 4.4.4 The Dispatcher
- About the author
- Chapter 7. The state machine
- Appendix E. Other resources and links
- Example NAT machine in theory
- The final stage of our NAT machine
- Compiling the user-land applications
- The conntrack entries
- Untracked connections and the raw table
- Basics of the iptables command
- Other debugging tools
- Setting up user specified chains in the filter table