iOS Development UIWebView

Transferred from: http://www.cnblogs.com/zhuqil/archive/2011/07/28/2119923.html

UIWebView is one of the most commonly used controls in the iOS SDK. is a built-in browser control that we can use to navigate the Web, open the document, and so on. In this article I will use this control to make a simple browser. Such as:

We create a window-based application program named: Uiwebviewdemo

The UIWebView loadrequest can be used to load a URL address, which requires a nsurlrequest parameter. We define a method to load the URL. Define the following methods in Uiwebviewdemoviewcontroller:

-(void) loadwebpagewithstring: (nsstring*) urlstring
{
    Nsurl *url =[nsurl urlwithstring:urlstring];
    NSLog (urlstring);
    Nsurlrequest *request =[nsurlrequest Requestwithurl:url];
    [WebView Loadrequest:request];
}

Place 3 controls on the interface, one TextField, one button, and one UIWebView, with the following layout:

Define related controls in code: WebView is used to display Web pages, TextField for the address bar, Activityindicatorview for loading animations, ButtonPress click events for buttons.

@interface UIWebViewDemoViewController :UIViewController<UIWebViewDelegate> {        IBOutlet UIWebView *webView;    IBOutlet UITextField *textField;    UIActivityIndicatorView *activityIndicatorView;    }- (IBAction)buttonPress:(id) sender;- (void)loadWebPageWithString:(NSString*)urlString;@end

Use IB to associate them.

Set UIWebView, Initialize Uiactivityindicatorview:

-(void) viewdidload
{
    [Super Viewdidload];
    Webview.scalespagetofit =yes;
    Webview.delegate =self;
    
                             Initwithframe:cgrectmake (0.0f, 0.0f, 32.0f, 32.0f)];
    [Activityindicatorview SetCenter:self.view.center];
    
    [Self.view Addsubview:activityindicatorview];
    [Self buttonpress:nil];
    Do any additional setup after loading the view from its nib.
}

UIWebView has the following principal methods:

1,-(void) Webviewdidstartload: (UIWebView *) WebView; The method is executed when the load is started.
2,-(void) Webviewdidfinishload: (UIWebView *) WebView; The method is executed when the load is complete.
3,-(void) WebView: (UIWebView *) WebView didfailloadwitherror: (nserror *) error, load error when the method is executed.

We can place the Activityindicatorview in the previous two delegate methods.

-(void) Webviewdidstartload: (UIWebView *) WebView
{
    [Activityindicatorview startanimating];
}
-(void) Webviewdidfinishload: (UIWebView *) WebView
{
    [Activityindicatorview stopanimating];
}

The ButtonPress method is simple, just call us to start defining the Loadwebpagewithstring method:

- (IBAction)buttonPress:(id) sender{    [textField resignFirstResponder];     [selfloadWebPageWithString:textField.text];    }

When there is an error in the request page, we give you a hint:

- (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];}

Summary: This article through the implementation of a simple browser, explains the UIWebView methods and properties, I believe that through this example, we should understand the use of UIWebView.

Code: Uiwebviewdemo.zip

iOS Development UIWebView