Programming iOS 6, 3rd Edition

UISearchBar

A search bar (UISearchBar) is essentially a wrapper for a text field; it has a text field as one of its subviews, though there is no official access to it. It is displayed by default as a rounded rectangle containing a magnifying glass icon, where the user can enter text (Figure 25-5). It does not, of itself, do any searching or display the results of a search; a common interface involves displaying the results of a search as a table, and the UISearchDisplayController class makes this easy to do (see Chapter 21).

Figure 25-5. A search bar with a search results button

A search bar’s current text is its text property. It can have a placeholder, which appears when there is no text. A prompt can be displayed above the search bar to explain its purpose. Delegate methods (UISearchBarDelegate) notify you of editing events; for their use, compare the text field and text view delegate methods discussed in Chapter 23:

• searchBarShouldBeginEditing:
• searchBarTextDidBeginEditing:
• searchBar:textDidChange:
• searchBar:shouldChangeTextInRange:replacementText:
• searchBarShouldEndEditing:
• searchBarTextDidEndEditing:

A search bar has a barStyle, for which your choices are UIBarStyleDefault or UIBarStyleBlack, and either translucent or not. Alternatively, the search bar may have a tintColor. The bar style and tint color are the same as for a navigation bar or toolbar (see later in this chapter), ...