在UIWebView中檢測點擊的圖像

Question

我有一個網絡視圖，顯示由他人完成的html + js簡介。 當用戶點擊特定的圖像時，我需要執行搜索。 我不懂JavaScript。 如果我嘗試使用.src返回空值，如果嘗試.innerHTML則總是返回很多代碼。 如何檢測這種特定的觸摸？ 謝謝。

- (void)viewDidLoad
{
    [super viewDidLoad];
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(viewTapped:)];
    [tap setDelegate:self];
    [self.webView.scrollView addGestureRecognizer:tap];

    NSString *htmlFile = [[NSBundle mainBundle] pathForResource:@"myFile" ofType:@"html" inDirectory:@"myDir"];
    NSURL* url = [[NSURL alloc]initFileURLWithPath:htmlFile];
    NSURLRequest* request = [NSURLRequest requestWithURL:url];
    [self.webView loadRequest:request];
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}
-(void)viewTapped:(UITapGestureRecognizer*)tap {
    CGPoint touchPoint = [tap locationInView:self.webView];
    NSString *js = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).src", touchPoint.x, touchPoint.y];
    NSString *urlToSave = [self.webView stringByEvaluatingJavaScriptFromString:js];
//Returning an empty string
    if (urlToSave.length > 0) {
          [self performSegueWithIdentifier:@"introToMain" sender:self];
    }

}

Answer 1

我認為您應該使html中的圖片可點擊。 如果是這樣，請忽略此。 然后，您應該使用UIWebView的shouldStartLoadWithRequest委托方法，如下所示：

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{


    if (navigationType == UIWebViewNavigationTypeLinkClicked){

        NSURL *url = request.URL;
        //Maybe you can detect the image here looking to the url.

    }

    return YES;

}