Objective-C Learning Notes - UIWebView4(坑)

在 iOS 应用中,当使用 UIWebView 控件在屏幕中显示指定的网页后,我们可以通过触摸的方式浏览指定的网页.

在具体实现时,是通过 webView:shouldStartLoadWithRequest:navigationType 方法来实现的.

其中 NavigationType 包括如下所示的可选参数值:

• UIWebViewNavigationTypeLinkClick //链接被触摸时请求这个链接

• UIWebViewNavigationTypeFormSubmitted //form 被提交时请求这个 form 的内容

• UIWebViewNavigationTypeBackForward //当通过 goBack 或者 goForward进行页面转移时移动目标 URL

• UIWebViewNavigationTypeReload //当页面重新导入时导入这个 URL

• UIWebViewNavigationTyoeOrther //使用 loadRequest 方法读取内容
  

#import <UIKit/UIKit.h>
@interface ViewController : UIViewController
@property (strong,nonatomic) UIWebView *myWebView;
@end

#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
@synthesize myWebView;
- (void)viewDidLoad {
    [super viewDidLoad];
    
    myWebView = [[UIWebView alloc]init];
    
    myWebView.frame = self.view.bounds;
    
    myWebView.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
    
    [self.view addSubview:myWebView];
    
    // Do any additional setup after loading the view, typically from a nib.
}
- (void)loadHTMLFile:(NSString *)path{
    NSArray *components = [path pathComponents];
    NSString *resourceName = [components lastObject];
    NSString *abslutePath;
    if ((abslutePath = [[NSBundle mainBundle]pathForResource:resourceName ofType:nil])){
        NSData *data = [NSData dataWithContentsOfFile:abslutePath];
        [myWebView loadData:data MIMEType:@"text/html" textEncodingName:@"utf-8" baseURL:nil];
    }else{
        NSLog(@"%@ not found!", resourceName);
    }
}

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
    
    if (UIWebViewNavigationTypeLinkClicked == navigationType){
        NSString *url = [[request URL] path];
        [self loadHTMLFile:url];
        return NO;
    }else if(UIWebViewNavigationTypeFormSubmitted == navigationType){
        NSString *url = [[request URL] path];
        NSArray *components = [url pathComponents];
        NSString *resultString = [webView stringByEvaluatingJavaScriptFromString:[components lastObject]];
        UIAlertView *alert = [[UIAlertView alloc]init];
        alert.message = resultString;
        [alert addButtonWithTitle:@"OK"];
        [alert show];
        return NO;
    }
    return YES;
}

- (void)viewDidAppear:(BOOL)animated{
    [super viewDidAppear:animated];
    [self loadHTMLFile:@"./top.html"];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
@end