UI控件---UIWebView

UIWebView是內置瀏覽器控件，能夠用來瀏覽網頁，文檔等，今天就試着作一個簡易的瀏覽器！

 

 

 

定義url的初始化方法和返回，前進，刷新三個方法，實現UIWebViewDelegate協議

@interface WebViewController : BaseViewController<UIWebViewDelegate>{
    
    NSString *_url;
}

-(id)initWithUrl:(NSString*)url;    //建立viewController的時候初始化url
- (IBAction)goBack:(id)sender;      //返回
- (IBAction)goForward:(id)sender;   //前進

- (IBAction)reload:(id)sender;      //刷新
@property (retain, nonatomic) IBOutlet UIWebView *webView;

@end

 

UIWebView的loadRequest方法能夠加載一個url地址，須要把url地址變成NSURLRequest參數

- (void)viewDidLoad
{
    [super viewDidLoad];

    NSURL *url = [NSURL URLWithString:_url];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    [_webView loadRequest:request];
    
    self.title = @"正在加載";
    
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;  //風火輪

}

 

3個方法的實現

- (IBAction)goBack:(id)sender{
    
    if ([_webView canGoBack]) {
        [_webView goBack];
    }
}
- (IBAction)goForward:(id)sender{

    if ([_webView canGoForward]) {
        [_webView goForward];
    }
    
}

- (IBAction)reload:(id)sender{
    
    [_webView reload];
}

實現協議方法，加載成功和加載失敗後調用的方法

#pragma mark - WebView Delegate
- (void)webViewDidFinishLoad:(UIWebView *)webView{
    
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;  //關閉風火輪
    NSString *title = [webView stringByEvaluatingJavaScriptFromString:@"document.title"];//解析JS代碼
    self.title = title;
    
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error{
    
    UIAlertView *alterview = [[UIAlertView alloc] initWithTitle:@"" message:[error localizedDescription]  delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
    [alterview show];
    [alterview release];
}

總結：瞭解了webView所須要的參數，加載過程，以及須要實現的協議方法