UIWebView之获取所点位置的图片标签和src

浏览数：47 / 时间：2015年06月09日

UIWebView有自己的UIResgure，如果我们手动加入自己的GestureRecognize将不能识别，如UILongPressGestureRecongnizer. 在浏览网页的时候，如果看到喜欢的图片，想把它保存下来如何办呢？我们可以自己写一个程序来实现，用uiwebview开发一个自己的浏览器。

上面说到uiwebview不能识别long press gesture，幸好有一个可以识别，那就是double click.因此我们注册它，代码如下

UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doubleTap:)];  
doubleTap.numberOfTouchesRequired = 2;  
[self.theWebView addGestureRecognizer:doubleTap];

然后就是实现doubleTap:

view plain
-(void) doubleTap :(UITapGestureRecognizer*) sender  
{  
    int scrollPositionY = [[self.theWebView stringByEvaluatingJavaScriptFromString:@"window.pageYOffset"] intValue];  
    int scrollPositionX = [[self.theWebView stringByEvaluatingJavaScriptFromString:@"window.pageXOffset"] intValue];  
      
    int displayWidth = [[self.theWebView stringByEvaluatingJavaScriptFromString:@"window.outerWidth"] intValue];  
    CGFloat scale = theWebView.frame.size.width / displayWidth;  
      
    CGPoint pt = [sender locationInView:self.theWebView];  
    pt.x *= scale;  
    pt.y *= scale;  
    pt.x += scrollPositionX;  
    pt.y += scrollPositionY;  
      
    NSString *js = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).tagName", pt.x, pt.y];  
    NSString * tagName = [self.theWebView stringByEvaluatingJavaScriptFromString:js];  
    if ([tagName isEqualToString:@"img"]) {  
        NSString *imgURL = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).src", pt.x, pt.y];  
        NSString *urlToSave = [self.theWebView stringByEvaluatingJavaScriptFromString:imgURL];  
        NSLog(@"image url=%@", urlToSave);  
    }  
}