UISearchBar 搜索框

UISearchBar 一般配合UITableView使用，当然也可以配合UITextView或者UIWebView使用。

先看他的几个属性：

 @property(nonatomic)        UIBarStyle              barStyle;              // default is UIBarStyleDefault (blue)
 @property(nonatomic,assign) id<UISearchBarDelegate> delegate;              // weak reference. default is nil
 @property(nonatomic,copy)   NSString               *text;                  // current/starting search text
 @property(nonatomic,copy)   NSString               *prompt;                // default is nil
 @property(nonatomic,copy)   NSString               *placeholder;           // default is nil
 @property(nonatomic)        BOOL                    showsBookmarkButton;   // default is NO
 @property(nonatomic)        BOOL                    showsCancelButton;     // default is NO
 @property(nonatomic)        BOOL                    showsSearchResultsButton __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_2); // default is NO
 @property(nonatomic, getter=isSearchResultsButtonSelected) BOOL searchResultsButtonSelected __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_2); // default is NO
 - (void)setShowsCancelButton:(BOOL)showsCancelButton animated:(BOOL)animated __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0);

 @property(nonatomic,retain) UIColor                *tintColor;             // default is nil
 @property(nonatomic,assign,getter=isTranslucent) BOOL translucent __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0); // Default is NO. Always YES if barStyle is set to UIBarStyleBlackTranslucent

 // available text input traits
 @property(nonatomic) UITextAutocapitalizationType autocapitalizationType;  // default is UITextAutocapitalizationTypeNone
 @property(nonatomic) UITextAutocorrectionType     autocorrectionType;      // default is UITextAutocorrectionTypeDefault
 @property(nonatomic) UITextSpellCheckingType      spellCheckingType;       // default is UITextSpellCheckingTypeDefault
 @property(nonatomic) UIKeyboardType               keyboardType;            // default is UIKeyboardTypeDefault

 @property(nonatomic,copy) NSArray   *scopeButtonTitles        __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0); // array of NSStrings. no scope bar shown unless 2 or more items
 @property(nonatomic)      NSInteger  selectedScopeButtonIndex __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0); // index into array of scope button titles. default is 0. ignored if out of range
 @property(nonatomic)      BOOL       showsScopeBar            __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0); // default is NO. if YES, shows the scope bar. call sizeToFit: to update frame

 // 1pt wide images and resizable images will be scaled or tiled according to the resizable area, otherwise the image will be tiled
 @property(nonatomic,retain) UIImage *backgroundImage __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_5_0) UI_APPEARANCE_SELECTOR;
 @property(nonatomic,retain) UIImage *scopeBarBackgroundImage __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_5_0) UI_APPEARANCE_SELECTOR;

再来看他的委托方法：

 @protocol UISearchBarDelegate <NSObject>

 @optional

 - (BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar;                      // return NO to not become first responder
 - (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar;                     // called when text starts editing
 - (BOOL)searchBarShouldEndEditing:(UISearchBar *)searchBar;                        // return NO to not resign first responder
 - (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar;                       // called when text ends editing
 - (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText;   // called when text changes (including clear)
 - (BOOL)searchBar:(UISearchBar *)searchBar shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0); // called before text changes

 - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar;                     // called when keyboard search button pressed
 - (void)searchBarBookmarkButtonClicked:(UISearchBar *)searchBar;                   // called when bookmark button pressed
 - (void)searchBarCancelButtonClicked:(UISearchBar *) searchBar;                    // called when cancel button pressed
 - (void)searchBarResultsListButtonClicked:(UISearchBar *)searchBar __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_2); // called when search results button pressed

 - (void)searchBar:(UISearchBar *)searchBar selectedScopeButtonIndexDidChange:(NSInteger)selectedScope __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0);

 @end

完了。