ios - 在 uiwebview 上添加事件指示器

Question

我有一个 viewDidLoad，它创建一个 Web View 并启动一个事件指示器。如何让事件指示器仅在网页出现时停止？如何向事件指示器添加单词，例如“正在加载”？

// Create the UIWebView
UIWebView *webView = [[UIWebView alloc] initWithFrame:self.view.bounds];

[self.view addSubview:webView];

// Start the throbber to check if the user exists
UIActivityIndicatorView *activityView=[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
activityView.center = CGPointMake([self screenWidth] / 2.0, 370.0);
[activityView startAnimating];
activityView.tag = 100;
[self.view addSubview:activityView];

NSString* url = @"http://google.com";
NSURL* nsUrl = [NSURL URLWithString:url];
NSURLRequest* request = [NSURLRequest requestWithURL:nsUrl cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:30];


// Remove activity view
UIView *viewToRemove = [self.view viewWithTag:100];
//[viewToRemove removeFromSuperview];

[webView loadRequest:request];

Answer 1

制作加载 View :

@implementation yourViewController{;
    UIView* loadingView;
}

在你的viewDidLoad :

loadingView = [[UIView alloc]initWithFrame:CGRectMake(100, 400, 80, 80)];
loadingView.backgroundColor = [UIColor colorWithWhite:0. alpha:0.6];
loadingView.layer.cornerRadius = 5;

UIActivityIndicatorView *activityView=[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
activityView.center = CGPointMake(loadingView.frame.size.width / 2.0, 35);
[activityView startAnimating];
activityView.tag = 100;
[loadingView addSubview:activityView];

UILabel* lblLoading = [[UILabel alloc]initWithFrame:CGRectMake(0, 48, 80, 30)];
lblLoading.text = @"Loading...";
lblLoading.textColor = [UIColor whiteColor];
lblLoading.font = [UIFont fontWithName:lblLoading.font.fontName size:15];
lblLoading.textAlignment = NSTextAlignmentCenter;
[loadingView addSubview:lblLoading];

[self.view addSubview:loadingView];

这个 View 看起来像这样:

注意，如果你想使用cornerRadius，你必须导入<QuartzCore/QuartzCore.h>框架，当然，在导入之前，添加 QuartzCore您项目的框架!

检测 webview 何时停止加载:

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    [loadingView setHidden:YES];
}

你必须执行 UIWebViewDelegate协议(protocol)，和

webView.delegate = self;

并使其可见:

- (void)webViewDidStartLoad:(UIWebView *)webView {

 [loadingView setHidden:NO];

}