UIWebView

1.UIWebView的基本用法

#import "ViewController.h"

@interface ViewController () 
@property (weak, nonatomic) IBOutlet UIWebView *webView;
@property (weak, nonatomic) IBOutlet UIBarButtonItem *backItem;
@property (weak, nonatomic) IBOutlet UIBarButtonItem *forward;
@end

@implementation ViewController
- (IBAction)back:(id)sender {
    [self.webView goBack];
}

- (IBAction)forward:(id)sender {
    [self.webView goForward];
}

- (IBAction)refresh:(id)sender {
    [self.webView reload];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // Native(OC+Swift) + HTML5
    
    self.webView.delegate = self;
    // 网页内容缩小到适应整个设备屏幕
//    self.webView.scalesPageToFit = YES;
    
    // 检测各种特殊的字符串：比如电话、网站
    self.webView.dataDetectorTypes = UIDataDetectorTypeAll;
    
    [self.webView loadRequest:[NSURLRequest requestWithURL:[[NSBundle mainBundle] URLForResource:@"test" withExtension:@"html"]]];
    
//    [self.webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.520it.com"]]];
    
//    [self.webView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:@"/Users/xiaomage/Desktop/test.pptx"]]];
    
//    [self.webView loadData:<#(NSData *)#> MIMEType:<#(NSString *)#> textEncodingName:<#(NSString *)#> baseURL:<#(NSURL *)#>];
    
//    [self.webView loadHTMLString:@"
哈哈哈哈哈
" baseURL:nil];
    
    self.webView.scrollView.contentInset = UIEdgeInsetsMake(20, 0, 0, 0);
}

#pragma mark - 
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
//    NSLog(@"%s", __func__);
    
    self.backItem.enabled = webView.canGoBack;
    self.forward.enabled = webView.canGoForward;
}

- (void)webViewDidStartLoad:(UIWebView *)webView
{
//    NSLog(@"%s", __func__);
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
//    NSLog(@"%s", __func__);
    
    self.backItem.enabled = webView.canGoBack;
    self.forward.enabled = webView.canGoForward;
}

/**
 * 每当webView即将发送一个请求之前，都会调用这个方法
 * 返回YES：允许加载这个请求
 * 返回NO：禁止加载这个请求
 */
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
//    NSLog(@"%@", request.URL);
    if ([request.URL.absoluteString containsString:@"life"]) return NO;
    
    // JS  JavaScript
    return YES;
}

@end

2.通过代理方法完成OC与js交互

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    // url == xmg://sendMessage_?200
    NSString *url = request.URL.absoluteString;
    NSString *scheme = @"xmg://";
    if ([url hasPrefix:scheme]) {
        // 获得协议后面的路径  path == sendMessage_number2_?200&300
        NSString *path = [url substringFromIndex:scheme.length];
        // 利用?切割路径
        NSArray *subpaths = [path componentsSeparatedByString:@"?"];
        // 方法名 methodName == sendMessage:number2:
        NSString *methodName = [[subpaths firstObject] stringByReplacingOccurrencesOfString:@"_" withString:@":"];
        // 参数  200&300
        NSString *param = [subpaths lastObject];
        NSArray *subparams = nil;
        if (subpaths.count == 2 || [param containsString:@"&"]) {
            subparams = [param componentsSeparatedByString:@"&"];
        }
        // 取出前面的2个参数
        NSString *firstParam = [subparams firstObject];
        NSString *secondParam = subparams.count <= 1 ? nil : [subparams lastObject];
        
        [self performSelector:NSSelectorFromString(methodName) withObject:firstParam withObject:secondParam];
        
        return NO;
    }
    
    NSLog(@"想加载其他请求，不是想调用OC的方法");
    
    return YES;
}