將活動指示器添加到Web視圖

Question

我想將活動指示器添加到Web視圖。 但我不知道什麼時候瀏覽網頁完成加載。 我開始在viewdidload中進行動畫製作。

Answer 1

你不應該開始viewDidLoad中動畫。順應

UIWebViewDelegate 

協議，能讓您的網絡視圖的委託您的視圖控制器，然後使用委託方法：

@interface MyVC: UIViewController <UIWebViewDelegate> { 
    UIWebView *webView; 
    UIActivityIndicatorView *activityIndicator; 
} 

@end 

@implementation MyVC 

- (id)init 
{ 
    self = [super init]; 
    // ... 

    activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite]; 
    activityIndicator.frame = CGRectMake(x, y, w, h); 
    [self.view addSubview:activityIndicator]; 

    webView = [[UIWebView alloc] initWithFrame:CGRectMake(x, y, w, h)]; 
    webView.delegate = self; 
    // ... 
    return self; 
} 

- (BOOL)webView:(UIWebView *)wv shouldStartLoadWithRequest:(NSURLRequest *)rq 
{ 
    [activityIndicator startAnimating]; 
    return YES; 
} 

- (void)webViewDidFinishLoading:(UIWebView *)wv 
{ 
    [activityIndicator stopAnimating]; 
} 

- (void)webView:(UIWebView *)wv didFailLoadWithError:(NSError *)error 
{ 
    [activityIndicator stopAnimating]; 
} 

@end 

Answer 2

您將希望聽取網絡視圖委託回調以正確顯示您的活動指示器。

具體來說，你會想傾聽：

webViewDidStartLoad：（啓動活動的指標動畫）

webViewDidFinishLoad：（到底）

web視圖：didFailLoadWithError：（到底）

http://developer.apple.com/library/ios/#documentation/uikit/reference/UIWebViewDelegate_Protocol/Reference/Reference.html

Answer 3

執行UIWebViewDelegate協議 這些都是你需要在你的代碼來實現代表：

- (void)webViewDidStartLoad:(UIWebView *)webView; //a web view starts loading 
- (void)webViewDidFinishLoad:(UIWebView *)webView;//web view finishes loading 
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error; //web view failed to load 

Answer 4

- (void)viewDidLoad { 
[super viewDidLoad]; 
// Do any additional setup after loading the view. 

self.webViewRef.delegate = self; 
NSURL *websiteUrl = [NSURL URLWithString:Constants.API_TERMS_AND_CONDITIONS_URL]; 
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:websiteUrl]; 
[self.webViewRef loadRequest:urlRequest]; 
} 

#pragma mark 
#pragma mark -- UIWebViewDelegate 
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{ 
[self.activityIndicator startAnimating]; 
return YES; 
} 
- (void)webViewDidStartLoad:(UIWebView *)webView{ 
[self.activityIndicator startAnimating]; 
} 
    - (void)webViewDidFinishLoad:(UIWebView *)webView{ 
[self.activityIndicator stopAnimating]; 
self.activityIndicator.hidden = YES; 
} 
- (void)webView:(UIWebView *)webView didFailLoadWithError:(nullable NSError *)error{ 
[self.activityIndicator stopAnimating]; 
self.activityIndicator.hidden = YES; 
}