iOS，在web视图上显示站点的特定html内容

我想从站点html的特定部分检索数据，并编写了以下代码。不幸的是，代码不起作用。我怎样才能解决这个问题

html类名为“topic_content”，适用站点中的每一篇文章都包含它（参见代码中的注释）

@implementation DetailViewController
....
UIActivityIndicator视图*activityIndicator；
-（无效）viewDidLoad{
.....
activityIndicator=[[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge]；
[活动指示器停止设置动画]；
....
[自述新闻]；
}
-（作废）callDetailNews{
....
if（[[Reachability reachabilityForInternetConnection]currentReachabilityStatus]！=NotReachable）
{
//文章链接：：http://el3en.com/?articles=topic&topic=20840 （令牌ID）
// 
//NSString*someHTML=[webView stringByEvaluatingJavaScriptFromString:@“document.getElementsByClassName（'box'）[0].innerHTML；”；
NSString*articleString=[NSString stringWithFormat:@”http://el3en.com/?articles=topic&topic=%@“，token_ID]；
NSURL*articleURL=[NSURL URLWithString:articleString]；
n错误*错误；
NSString*articlePage=[NSString stringWithContentsOfURL:articleURL
编码：NSASCIIStringEncoding
错误：&错误]；
[_webviewloadhtmlstring:articlePage baseURL:nil]；
//NSString*someHTML=[[u webView stringByEvaluatingJavaScriptFromString:@“document.getElementsByClassName（'topic_content'）[0]。innerHTML；”]；
//NSLog（@“Content:%@”，someHTML）；
}
.....
}
-（void）webView加载：（UIWebView*）webView{
[活动指示器启动激活]；
self.webView.hidden=true；
}
-（void）webViewDidFinishLoad:（UIWebView*）webView{
[self.webView stringByEvaluatingJavaScriptFromString:@“document.getElementsByCassName（'topic_content'）[0].sinnerHTML；”；
[活动指示器停止设置动画]；
self.webView.hidden=false；
}

---

谢谢

您应该使用innerHtml而不是RHTML，除此之外，您还需要获取字符串并将此字符串加载到另一个Web视图中。请看例子

#import "ViewController.h"

@interface ViewController ()
@property (strong, nonatomic) IBOutlet UIWebView *fakeView;
@end

@implementation ViewController


UIActivityIndicatorView *activityIndicator;

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    [activityIndicator stopAnimating];



    [self callDetailNews];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


-(void)callDetailNews{

    if ([[Reachability reachabilityForInternetConnection]currentReachabilityStatus]!=NotReachable)
    {
        // article link :: http://el3en.com/?articles=topic&topic=20840 (token_ID)

        // <td class="topic_content" colspan='6' itemprop="articleBody"  style="text-align:justify;  word-wrap: break-word; width:100%">

        // NSString *someHTML = [webView stringByEvaluatingJavaScriptFromString:@"document.getElementsByClassName('box')[0].innerHTML;"];

        NSString *articleString = [NSString stringWithFormat:@"http://el3en.com/?articles=topic&topic=%@",@"20840"];

        NSURL *articleURL = [NSURL URLWithString:articleString];
        NSError *error;
        NSString *articlePage = [NSString stringWithContentsOfURL:articleURL
                                                         encoding:NSASCIIStringEncoding
                                                            error:&error];

        NSLog(@"Request %@",articleURL);
    self.fakeView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
        self.fakeView.delegate = self;
        [self.fakeView loadRequest:[NSURLRequest requestWithURL:articleURL]];

        //NSString *someHTML = [_webView stringByEvaluatingJavaScriptFromString:@"document.getElementsByClassName('topic_content')[0].innerHTML;"];
        //NSLog(@"Content : %@",someHTML);
    }

}

- (void)webViewDidStartLoad:(UIWebView *)webView {
    [activityIndicator startAnimating];
    self.webView.hidden=true;
}

-(void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
    NSLog(@"error %@" ,[error description]);
}

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

    if(webView == self.fakeView) {
        NSString* javascriptString = [self.fakeView stringByEvaluatingJavaScriptFromString:@"document.getElementsByClassName('topic_content')[0].innerHTML"];

        NSLog(@"%@",javascriptString);
        [self.webView loadHTMLString:javascriptString baseURL:[NSURL URLWithString:@""]];
        self.fakeView = nil;
    }else{
        [activityIndicator stopAnimating];
        self.webView.hidden=false;
    }
}
@end

#导入“ViewController.h”
@界面视图控制器（）
@属性（强，非原子）ibuiwebview*fakeView；
@结束
@实现视图控制器
UIActivityIndicator视图*activityIndicator；
-（无效）viewDidLoad{
[超级视图下载]；
//加载视图后，通常从nib执行任何其他设置。
activityIndicator=[[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge]；
[活动指示器停止设置动画]；
[自述新闻]；
}
-（无效）未收到记忆警告{
[超级记忆警告]；
//处置所有可以重新创建的资源。
}
-（作废）callDetailNews{
if（[[Reachability reachabilityForInternetConnection]currentReachabilityStatus]！=NotReachable）
{
//文章链接：：http://el3en.com/?articles=topic&topic=20840 （令牌ID）
// 
//NSString*someHTML=[webView stringByEvaluatingJavaScriptFromString:@“document.getElementsByClassName（'box'）[0].innerHTML；”；
NSString*articleString=[NSString stringWithFormat:@”http://el3en.com/?articles=topic&topic=%@",@"20840"];
NSURL*articleURL=[NSURL URLWithString:articleString]；
n错误*错误；
NSString*articlePage=[NSString stringWithContentsOfURL:articleURL
编码：NSASCIIStringEncoding
错误：&错误]；
NSLog（@“请求%@”，articleURL）；
self.fakeView=[[UIWebView alloc]initWithFrame:CGRectMake（0,0,1024,768）]；
self.fakeView.delegate=self；
[self.fakeView加载请求：[nsurlRequestRequestWithURL:articleURL]]；
//NSString*someHTML=[[u webView stringByEvaluatingJavaScriptFromString:@“document.getElementsByClassName（'topic_content'）[0]。innerHTML；”]；
//NSLog（@“Content:%@”，someHTML）；
}
}
-（void）webView加载：（UIWebView*）webView{
[活动指示器启动激活]；
self.webView.hidden=true；
}
-（void）webView:（UIWebView*）webView失败加载错误：（NSError*）错误{
NSLog（@“错误%@，[错误描述]）；
}
-（无效）webViewDidFinishLoad:（UIWebView*）webView{
if（webView==self.fakeView）{
NSString*javascriptString=[self.fakeView stringByEvaluatingJavaScriptFromString:@“document.getElementsByClassName（'topic_content'）[0].innerHTML”]；
NSLog（@“%@”，javascriptString）；
[self.webView loadHTMLString:javascriptString baseURL:[NSURL URLWithString:@”“]；
self.fakeView=nil；
}否则{
[活动指示器停止设置动画]；
self.webView.hidden=false；
}
}
@结束

您应该使用innerHtml而不是RHTML，除此之外，您还需要获取字符串并将该字符串加载到另一个Web视图中。请看例子

#import "ViewController.h"

@interface ViewController ()
@property (strong, nonatomic) IBOutlet UIWebView *fakeView;
@end

@implementation ViewController


UIActivityIndicatorView *activityIndicator;

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    [activityIndicator stopAnimating];



    [self callDetailNews];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


-(void)callDetailNews{

    if ([[Reachability reachabilityForInternetConnection]currentReachabilityStatus]!=NotReachable)
    {
        // article link :: http://el3en.com/?articles=topic&topic=20840 (token_ID)

        // <td class="topic_content" colspan='6' itemprop="articleBody"  style="text-align:justify;  word-wrap: break-word; width:100%">

        // NSString *someHTML = [webView stringByEvaluatingJavaScriptFromString:@"document.getElementsByClassName('box')[0].innerHTML;"];

        NSString *articleString = [NSString stringWithFormat:@"http://el3en.com/?articles=topic&topic=%@",@"20840"];

        NSURL *articleURL = [NSURL URLWithString:articleString];
        NSError *error;
        NSString *articlePage = [NSString stringWithContentsOfURL:articleURL
                                                         encoding:NSASCIIStringEncoding
                                                            error:&error];

        NSLog(@"Request %@",articleURL);
    self.fakeView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
        self.fakeView.delegate = self;
        [self.fakeView loadRequest:[NSURLRequest requestWithURL:articleURL]];

        //NSString *someHTML = [_webView stringByEvaluatingJavaScriptFromString:@"document.getElementsByClassName('topic_content')[0].innerHTML;"];
        //NSLog(@"Content : %@",someHTML);
    }

}

- (void)webViewDidStartLoad:(UIWebView *)webView {
    [activityIndicator startAnimating];
    self.webView.hidden=true;
}

-(void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
    NSLog(@"error %@" ,[error description]);
}

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

    if(webView == self.fakeView) {
        NSString* javascriptString = [self.fakeView stringByEvaluatingJavaScriptFromString:@"document.getElementsByClassName('topic_content')[0].innerHTML"];

        NSLog(@"%@",javascriptString);
        [self.webView loadHTMLString:javascriptString baseURL:[NSURL URLWithString:@""]];
        self.fakeView = nil;
    }else{
        [activityIndicator stopAnimating];
        self.webView.hidden=false;
    }
}
@end

#导入“ViewController.h”
@界面视图控制器（）
@属性（强，非原子）ibuiwebview*fakeView；
@结束
@实现视图控制器
UIActivityIndicator视图*activityIndicator；
-（无效）viewDidLoad{
[超级视图下载]；
//加载视图后，通常从nib执行任何其他设置。
activityIndicator=[[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge]；
[活动指示器停止设置动画]；
[自述新闻]；
}
-（无效）未收到记忆警告{
[超级记忆警告]；
//处置所有可以重新创建的资源。
}
-（作废）callDetailNews{
if（[[Reachability reachabilityForInternetConnection]currentReachabilityStatus]！=NotReachable）
{
//文章链接：：http://el3en.com/?articles=topic&to