UISearchBar 的基础设置：

• (void)setBarButtonItem
  {
  //隐藏导航栏上的返回按钮
  [self.navigationItem setHidesBackButton:YES];
  //用来放searchBar的View
  UIView *titleView = [[UIView alloc] initWithFrame:CGRectMake(5, 7, self.view.frame.size.width, 30)];
  //创建searchBar
  UISearchBar *searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(titleView.frame) - 15, 30)];
  //默认提示文字
  searchBar.placeholder = @"搜索内容";
  //背景图片
  searchBar.backgroundImage = [UIImage imageNamed:@"clearImage"];
  //代理
  searchBar.delegate = self;
  //显示右侧取消按钮
  searchBar.showsCancelButton = YES;
  //光标颜色
  searchBar.tintColor = UIColorFromRGB(0x595959);
  //拿到searchBar的输入框
  UITextField *searchTextField = [searchBar valueForKey:@"_searchField"];
  //字体大小
  searchTextField.font = [UIFont systemFontOfSize:15];
  //输入框背景颜色
  searchTextField.backgroundColor = [UIColor colorWithRed:234/255.0 green:235/255.0 blue:237/255.0 alpha:1];
  //拿到取消按钮
  UIButton *cancleBtn = [searchBar valueForKey:@"cancelButton"];
  //设置按钮上的文字
  [cancleBtn setTitle:@"取消" forState:UIControlStateNormal];
  //设置按钮上文字的颜色
  [cancleBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
  [titleView addSubview:searchBar];
  self.searchBar = searchBar;
  self.navigationItem.titleView = titleView;
  }

代理方法：

pragma mark - UISearchBarDelegate

• (BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar{
  return YES;
  }

• (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar {
  searchBar.showsCancelButton = YES;
  }

• (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
  {
  NSLog(@"SearchButton");
  }

• (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
  {
  [self.searchBar resignFirstResponder];
  [self.navigationController popViewControllerAnimated:YES];
  }

• (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar
  {
  searchBar.showsCancelButton = YES;
  }

• (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
  {
  NSString *inputStr = searchText;
  [self.results removeAllObjects];
  for (ElderModel *model in self.dataArray) {
  if ([model.name.lowercaseString rangeOfString:inputStr.lowercaseString].location != NSNotFound) {
  [self.results addObject:model];
  }
  }
  [self.tableView reloadData];
  }

  // 找到searchbar的searchField属性
  UITextField *searchField = [self.searchBar valueForKey:@"searchField"];
  if (searchField) {
  // 背景色
  [searchField setBackgroundColor:[UIColor colorWithRed:0.074 green:0.649 blue:0.524 alpha:1.000]];
  // 设置字体颜色 & 占位符 (必须)
  searchField.textColor = [UIColor whiteColor];
  searchField.placeholder = @"placeholder";
  // 根据@"_placeholderLabel.textColor" 找到placeholder的字体颜色
  [searchField setValue:[UIColor whiteColor] forKeyPath:@"_placeholderLabel.textColor"];
  // 圆角
  searchField.layer.cornerRadius = 10.0f;
  searchField.layer.masksToBounds = YES;

  }

// searchBar 图标设置
[self.searchBar setImage:[UIImage imageNamed:@"magnifier"] forSearchBarIcon:UISearchBarIconSearch state:UIControlStateNormal];