//搜索框
    UISearchBar *searchBar = [[UISearchBar alloc] init];
//    searchBar.delegate = self;
    searchBar.frame = CGRectMake(10, 0, screenW-80, titleView.bounds.size.height);
    searchBar.layer.cornerRadius = 17;
    searchBar.layer.masksToBounds = YES;
    [searchBar.layer setBorderWidth:8];
    [searchBar.layer setBorderColor:[UIColor whiteColor].CGColor];  //設置邊框為白色
    searchBar.placeholder = @"請輸入目的地";
    searchBar.translucent = YES;
    searchBar.searchBarStyle = UISearchBarStyleProminent;
    //改變占位符的字體大小顏色
    UITextField * searchField = [searchBar valueForKey:@"_searchField"];
    [searchField setValue:[UIColor lightGrayColor] forKeyPath:@"_placeholderLabel.textColor"];
    [searchField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];
    //改變左邊搜索圖標坐標位置。后面的占位符蘋果已經(jīng)做好約束總是跟隨在搜索??圖標后面。
    [searchBar setPositionAdjustment:UIOffsetMake(60, 0) forSearchBarIcon:UISearchBarIconSearch];
設置搜索欄中圖片的位置偏移，圖片的枚舉如下：
typedef NS_ENUM(NSInteger, UISearchBarIcon) {

    UISearchBarIconSearch, //搜索圖標

    UISearchBarIconClear, // 清除圖標

    UISearchBarIconBookmark, // 書本圖標

    UISearchBarIconResultsList, // 結果列表圖標

};

下面是搜索框控件的一些代理方法：

- (BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar;           

將要開始編輯時的回調(diào)，返回為NO，則不能編輯

- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar;                  

已經(jīng)開始編輯時的回調(diào)

- (BOOL)searchBarShouldEndEditing:(UISearchBar *)searchBar;                

將要結束編輯時的回調(diào)

- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar;                   

已經(jīng)結束編輯的回調(diào)

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText;   編輯文字改變的回調(diào)

- (BOOL)searchBar:(UISearchBar *)searchBar shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text ; 

編輯文字改變前的回調(diào)，返回NO則不能加入新的編輯文字

- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar;       

搜索按鈕點擊的回調(diào)

- (void)searchBarBookmarkButtonClicked:(UISearchBar *)searchBar;             

書本按鈕點擊的回調(diào)

- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar;               

取消按鈕點擊的回調(diào)

- (void)searchBarResultsListButtonClicked:(UISearchBar *)searchBar; 

搜索結果按鈕點擊的回調(diào)

- (void)searchBar:(UISearchBar *)searchBar selectedScopeButtonIndexDidChange:(NSInteger)selectedScope;

搜索欄的附加試圖中切換按鈕觸發(fā)的回調(diào)

D7C05039-1BCD-40EA-801F-F3BD6C8CDE41.png