iOS应用中网络等待Loading的实现方法详解手机开发

UIWebView加载Loading…两种方法

第一种方法：使用UIView and UIActivityIndicatorView

//创建UIWebView 
WebView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 44, 320, 400)]; 
[WebView setUserInteractionEnabled:NO]; 
[WebView setBackgroundColor:[UIColor clearColor]]; 
[WebView setDelegate:self]; 
[WebView setOpaque:NO];//使网页透明 
 
NSString *path = @"http://www.baidu.com"; 
NSURL *url = [NSURL URLWithString:path]; 
[WebView loadRequest:[NSURLRequest requestWithURL:url]]; 
 
//创建UIActivityIndicatorView背底半透明View     
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)]; 
[view setTag:103]; 
[view setBackgroundColor:[UIColor blackColor]]; 
[view setAlpha:0.8]; 
[self.view addSubview:view]; 
 
activityIndicator = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 32.0f, 32.0f)]; 
[activityIndicator setCenter:view.center]; 
[activityIndicator setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleWhite]; 
[view addSubview:activityIndicator]; 
[self.view addSubview:WebView]; 
[view release]; 
[WebView release]; 
 
//开始加载数据 
- (void)webViewDidStartLoad:(UIWebView *)webView {     
      [activityIndicator startAnimating];          
} 
 
//数据加载完 
- (void)webViewDidFinishLoad:(UIWebView *)webView { 
     [activityIndicator stopAnimating];     
     UIView *view = (UIView *)[self.view viewWithTag:103]; 
     [view removeFromSuperview]; 
} 

  第二种方法：使用UIAlertView and UIActivityIndicatorView

/加载网页动画 
- (void)webViewDidStartLoad:(UIWebView *)webView{ 
    if (myAlert==nil){         
       myAlert = [[UIAlertView alloc] initWithTitle:nil  
                                                              message: @"读取中..." 
                                                                delegate: self 
                                                 cancelButtonTitle: nil 
                                                 otherButtonTitles: nil]; 
 
     UIActivityIndicatorView *activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite]; 
     activityView.frame = CGRectMake(120.f, 48.0f, 38.0f, 38.0f); 
     [myAlert addSubview:activityView]; 
     [activityView startAnimating]; 
     [myAlert show]; 
     } 
} 
 
- (void)webViewDidFinishLoad:(UIWebView *)webView{  
      [myAlert dismissWithClickedButtonIndex:0 animated:YES]; 
}