#import "WebViewController.h"@interface WebViewController (){    UIWebView *_webView;    UITextField *_textField;    UIActivityIndicatorView *_activityIndicatorView;}@end@implementation WebViewController-(void)dealloc{    [_webView release];    [_textField release];    [_activityIndicatorView release];    [super dealloc];}//webView获取url地址- (void)loadWebPageWithString:(NSString *)urlstring{    NSURL *url = [NSURL URLWithString:urlstring];    NSURLRequest *request = [NSURLRequest requestWithURL:url];    [_webView loadRequest:request];}//点击按钮,网页加载- (void)buttonPress:(id)sender{    [_textField resignFirstResponder];    [self loadWebPageWithString:_textField.text];}//代理中的方法-(void)webViewDidStartLoad:(UIWebView *)webView{    //网页加载时  进度轮开始启动    [_activityIndicatorView startAnimating];}- (void)webViewDidFinishLoad:(UIWebView *)webView{    //网页加载完成  进度轮停止    [_activityIndicatorView stopAnimating];}//请求页面出现错误:- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error{    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:@"网址输入错误或网络断开" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];    [alertView show];    [alertView release];}- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // Custom initialization    }    return self;}- (void)viewDidLoad{    [super viewDidLoad];    _textField = [[UITextField alloc] initWithFrame:CGRectMake(10, 20, 270, 30)];    _textField.borderStyle = UITextBorderStyleRoundedRect;    //输入框默认显示http://www.baidu.com    _textField.text = @"http://www.baidu.com";    //点击button进入网页    UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];    button.frame = CGRectMake(280, 20, 30, 30);    [button setTitle:@"GO" forState:UIControlStateNormal];    [button addTarget:self action:@selector(buttonPress:) forControlEvents:UIControlEventTouchUpInside];    //网页显示    _webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 50, 320, 425)];    _webView.delegate = self;    [self.view addSubview:_webView];    [self.view addSubview:_textField];    [self.view addSubview:button];    //设置进度轮    _activityIndicatorView = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 32, 32)];    //进度轮中心位置    [_activityIndicatorView setCenter:self.view.center];    //进度轮显示类型    [_activityIndicatorView setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleWhite];    [self.view addSubview:_activityIndicatorView];    //没有点击按钮时,执行方法进入默认显示网页    [self buttonPress:nil];        // Do any additional setup after loading the view.}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}/*#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{    // Get the new view controller using [segue destinationViewController].    // Pass the selected object to the new view controller.}*/@end