IOS ObjectC与javascript交互详解及实现代码

#import "ViewController.h"@interface ViewController ()<UIWebViewDelegate>@property (weak, nonatomic) IBOutlet UIWebView *webView;@end- (void)viewDidLoad {  [super viewDidLoad];  // 设置webView的代理  self.webView.delegate = self;  // 加载网页数据  NSURL *URL = [NSURL URLWithString:@"http://m.dianping.com/tuan/deal/5501525"];//  NSURL *URL = [NSURL URLWithString:@"https://www.hao123.com/?tn=93321723_hao_pg"];  NSURLRequest *request = [NSURLRequest requestWithURL:URL];  [self.webView loadRequest:request];}

/// 网页加载完成之后调用的代理方法 : JS注入 : OC调用JS代码- (void)webViewDidFinishLoad:(UIWebView *)webView{  // 用于拼接JS代码的字符串  NSMutableString *stringM = [NSMutableString string];  // 拼接移除顶部导航的JS代码  [stringM appendString:@"var headerTag = document.getElementsByTagName('header')[0]; headerTag.parentNode.removeChild(headerTag);"];  // 拼接移除橙色按钮的JS代码  [stringM appendString:@"var footerBtnTag = document.getElementsByClassName('footer-btn-fix')[0]; footerBtnTag.parentNode.removeChild(footerBtnTag);"];  // 拼接移除底部布局的JS代码  [stringM appendString:@"var footerTag = document.getElementsByClassName('footer')[0]; footerTag.parentNode.removeChild(footerTag);"];  // 拼接给img标签添加点击事件的JS代码  [stringM appendString:@"var imgTag = document.getElementsByTagName('figure')[0].children[0]; imgTag.onclick = function(){window.location.href='https://www.baidu.com'};"];  // 这个方法就是UIWebView提供的.专门做JS注入的方法  [webView stringByEvaluatingJavaScriptFromString:stringM];}

imgTag.onclick = function(){window.location.href='https://www.baidu.com‘} 

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{  // 获取拦截到的所有的请求  NSString *URLString = request.URL.absoluteString;  //https://m.baidu.com/?from=1015143h  //  NSLog(@"%@",URLString);  if ([URLString isEqualToString:@"https://m.baidu.com/?from=1015143h"]) {    NSLog(@"我点击的是imgTag");    // 当我知道点击的是imgTag时,自动push    //http://www.csdn.net/    NSURL *URL = [NSURL URLWithString:@"http://www.csdn.net/"];    NSURLRequest *request = [NSURLRequest requestWithURL:URL];    [self.webView loadRequest:request];//    TestViewController *testVC = [[TestViewController alloc] init];//    [self.navigationController pushViewController:testVC animated:YES];    // 因为这个地址是无效地址.不需要加载的    return NO;  }  // 返回YES的作用 : 表示你拦截到的请求,允许正常的发送出去;反之,不允许拦截到的请求发送出去  return YES;}