webView(简单的浏览器)

 #import "MJViewController.h"

 @interface MJViewController () <UISearchBarDelegate, UIWebViewDelegate>

 @property (weak, nonatomic) IBOutlet UIWebView *webView;
 @property (weak, nonatomic) IBOutlet UIBarButtonItem *backButton;
 @property (weak, nonatomic) IBOutlet UIBarButtonItem *forwarButton;

 @end

 @implementation MJViewController

 - (void)viewDidLoad
 {
     [super viewDidLoad];

     [self loadString:@"http://m.baidu.com"];
 }

 // 让浏览器加载指定的字符串,使用m.baidu.com进行搜索
 - (void)loadString:(NSString *)str
 {
     // 1. URL 定位资源,需要资源的地址
     NSString *urlStr = str;
     if (![str hasPrefix:@"http://"]) {
         urlStr = [NSString stringWithFormat:@"http://m.baidu.com/s?word=%@", str];
     }

     NSURL *url = [NSURL URLWithString:urlStr];

     // 2. 把URL告诉给服务器,请求,从m.baidu.com请求数据
     NSURLRequest *request = [NSURLRequest requestWithURL:url];

     // 3. 发送请求给服务器
     [self.webView loadRequest:request];
 }

 #pragma mark - 搜索栏代理
 // 开始搜索
 - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
 {
     NSLog(@"%@", searchBar.text);
     [self loadString:searchBar.text];

     [self.view endEditing:YES];
 }

 // 文本改变
 - (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
 {
     NSLog(@"searchText - %@", searchText);
 }

 #pragma mark - WebView代理方法
 #pragma mark 完成加载,页面链表数据会更新
 - (void)webViewDidFinishLoad:(UIWebView *)webView
 {
     // 根据webView当前的状态,来判断按钮的状态
     self.backButton.enabled = webView.canGoBack;
     self.forwarButton.enabled = webView.canGoForward;
 }

 @end