初始化：UISearchBar继承于UIView，我们可以像创建View那样创建searchBar
    UISearchBar * bar = [[UISearchBar alloc]initWithFrame:CGRectMake(20, 100, 250, 40)];    [self.view addSubview:bar];

@property(nonatomic)        UIBarStyle              barStyle; 
这个属性可以设置searchBar的搜索框的风格，枚举如下：
typedef NS_ENUM(NSInteger, UIBarStyle) {    UIBarStyleDefault          = 0,//默认风格 白色搜索框，多出的背景为灰色    UIBarStyleBlack            = 1,//黑色风格，黑色的搜索框    //下面两个枚举已经被禁用，作用和黑色风格一样    UIBarStyleBlackOpaque      = 1, // Deprecated. Use UIBarStyleBlack    UIBarStyleBlackTranslucent = 2, // Deprecated. Use UIBarStyleBlack and set the translucent property to YES};

 
@property(nonatomic,copy)   NSString               *text; 
设置搜索框中的文字
 
@property(nonatomic,copy)   NSString               *prompt; 
这个属性的官方解释是在搜索框顶部显示一行文字，其实就是背景文字，上图说明：
   bar.prompt = @"搜索框";   bar.text=@"321111111111111111111111111"

效果如下：
![](http://upload-images.jianshu.io/upload_images/646265-bb7c2dc22740103c.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
 
@property(nonatomic,copy)   NSString               *placeholder;  
和其他文本输入控件的placeholder相同，在输入文字时就会消失
@property(nonatomic)        BOOL                    showsBookmarkButton; 
是否在搜索框右侧显示一个图书的按钮，默认为NO，YES的效果如下：
![](http://upload-images.jianshu.io/upload_images/646265-4f15754a1bf8623c.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
@property(nonatomic)        BOOL                    showsCancelButton;
是否显示取消按钮，默认为NO，YES的效果如下：
![](http://upload-images.jianshu.io/upload_images/646265-67324056d98301d5.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
@property(nonatomic)        BOOL                    showsSearchResultsButton;
是否显示搜索结果按钮，默认为NO，YES效果如下：
![](http://upload-images.jianshu.io/upload_images/646265-1155a7f69205cab0.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
 
@property(nonatomic, getter=isSearchResultsButtonSelected) BOOL searchResultsButtonSelected ;
设置搜索结果按钮的选中状态
- (void)setShowsCancelButton:(BOOL)showsCancelButton animated:(BOOL)animated;
设置显示取消按钮
@property(nonatomic,retain) UIColor *tintColor;
设置这个颜色值会影响搜索框中的光标的颜色
 
@property(nonatomic,retain) UIColor *barTintColor;
设置这个颜色会影响搜索框的背景颜色
 
@property (nonatomic) UISearchBarStyle searchBarStyle;
设置搜索框整体的风格，枚举如下：
typedef NS_ENUM(NSUInteger, UISearchBarStyle) {    UISearchBarStyleDefault,    // currently UISearchBarStyleProminent    UISearchBarStyleProminent,  // 显示背景    UISearchBarStyleMinimal     // 不显示背景} NS_ENUM_AVAILABLE_IOS(7_0);

 
@property(nonatomic,assign,getter=isTranslucent) BOOL translucent;
设置是否半透明
@property(nonatomic)      BOOL       showsScopeBar ;
是否显示搜索栏的附件选择按钮试图，要想显示这个试图，首先要将这个属性设置为YES，之后给按钮数组中添加按钮，使用下面这个属性：
@property(nonatomic,copy) NSArray   *scopeButtonTitles ；
设置选择按钮试图的按钮标题
@property(nonatomic)      NSInteger  selectedScopeButtonIndex;
设置一个默认的选中按钮
    bar = [[UISearchBar alloc]initWithFrame:CGRectMake(20, 100, 250, 200)];    bar.showsScopeBar=YES;    bar.scopeButtonTitles = @[@"12",@"2",@"3",@"4"];

![](http://upload-images.jianshu.io/upload_images/646265-2124acef46e94782.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
@property (nonatomic, readwrite, retain) UIView *inputAccessoryView;
键盘的附属试图
@property(nonatomic,retain) UIImage *backgroundImage;
设置搜索框的背景图案
@property(nonatomic,retain) UIImage *scopeBarBackgroundImage;
设置附属选择按钮视图的背景图案
 
- (void)setBackgroundImage:(UIImage *)backgroundImage forBarPosition:(UIBarPosition)barPosition barMetrics:(UIBarMetrics)barMetrics ;  
- (UIImage *)backgroundImageForBarPosition:(UIBarPosition)barPosition barMetrics:(UIBarMetrics)barMetrics
这一对方法可以设置和获取某个状态枚举下的搜索框的背景图案
 
 
- (void)setSearchFieldBackgroundImage:(UIImage *)backgroundImage forState:(UIControlState)state;
- (UIImage *)searchFieldBackgroundImageForState:(UIControlState)state;
这一对方法用于设置和获取搜索框中TextField的背景图案
 
- (void)setImage:(UIImage *)iconImage forSearchBarIcon:(UISearchBarIcon)icon state:(UIControlState)state ;
- (UIImage *)imageForSearchBarIcon:(UISearchBarIcon)icon state:(UIControlState)state ;
这一对方法用于获取和设置搜索栏icon图片的图案
- (void)setScopeBarButtonBackgroundImage:(UIImage *)backgroundImage forState:(UIControlState)state; 
- (UIImage *)scopeBarButtonBackgroundImageForState:(UIControlState)state;
这一对方法用于设置和获取搜索框的附加选择按钮视图的背景图案
 
 
- (void)setScopeBarButtonDividerImage:(UIImage *)dividerImage forLeftSegmentState:(UIControlState)leftState rightSegmentState:(UIControlState)rightState;
- (UIImage *)scopeBarButtonDividerImageForLeftSegmentState:(UIControlState)leftState rightSegmentState:(UIControlState)rightState;
这一对方法用于获取和设置附加选择按钮视图中切换按钮的图案
 
- (void)setScopeBarButtonTitleTextAttributes:(NSDictionary *)attributes forState:(UIControlState)state;
- (NSDictionary *)scopeBarButtonTitleTextAttributesForState:(UIControlState)state;
这一对方法用于设置和获取切换按钮标题文字的字体属性字典
 
 
@property(nonatomic) UIOffset searchFieldBackgroundPositionAdjustment;
搜索文字在搜索框中的位置偏移
@property(nonatomic) UIOffset searchTextPositionAdjustment;
textfield在搜索框中的位置偏移
 
- (void)setPositionAdjustment:(UIOffset)adjustment forSearchBarIcon:(UISearchBarIcon)icon;
- (UIOffset)positionAdjustmentForSearchBarIcon:(UISearchBarIcon)icon;
设置搜索栏中图片的位置偏移，图片的枚举如下：
typedef NS_ENUM(NSInteger, UISearchBarIcon) {    UISearchBarIconSearch, //搜索图标    UISearchBarIconClear, // 清除图标    UISearchBarIconBookmark, // 书本图标    UISearchBarIconResultsList, // 结果列表图标};

 
下面是搜索框控件的一些代理方法：
 
- (BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar;           
将要开始编辑时的回调，返回为NO，则不能编辑
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar;                  
已经开始编辑时的回调
- (BOOL)searchBarShouldEndEditing:(UISearchBar *)searchBar;                
将要结束编辑时的回调
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar;                   
已经结束编辑的回调
- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText;   编辑文字改变的回调
- (BOOL)searchBar:(UISearchBar *)searchBar shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text ; 
编辑文字改变前的回调，返回NO则不能加入新的编辑文字
- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar;       
搜索按钮点击的回调
- (void)searchBarBookmarkButtonClicked:(UISearchBar *)searchBar;             
书本按钮点击的回调
- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar;               
取消按钮点击的回调
- (void)searchBarResultsListButtonClicked:(UISearchBar *)searchBar; 
搜索结果按钮点击的回调
 
- (void)searchBar:(UISearchBar *)searchBar selectedScopeButtonIndexDidChange:(NSInteger)selectedScope;
搜索栏的附加试图中切换按钮触发的回调