一、在源文件(asp、php)里做判断。这个方法最好,减少页面的冗余代码,对蜘蛛最友好;
二、JS里做判断:
1、先得有图片的参照值(初始值);
2、如果是幻灯片的话最好遍历并缓存图片到数组,在切换图片时再以现图片地址与数组里的图片数据对比,如果不同图片就显示或隐藏。
在网页加载完成时,通过js获取图片和添加点击的识别方式- (void)webViewDidFinishLoad:(UIWebView *)webView {
[IDProgressHUD IDPlaceViewHideDirect:self.view]
//这里是js,主要目的实现对url的获取
static NSString * const jsGetImages =
@"function getImages(){\
var objs = document.getElementsByTagName(\"img\")\
var imgScr = ''\
for(var i=0i<objs.lengthi++){\
imgScr = imgScr + objs[i].src + '+'\
}\
return imgScr\
}"
[webView stringByEvaluatingJavaScriptFromString:jsGetImages]//注入js方法
NSString *urlResurlt = [webView stringByEvaluatingJavaScriptFromString:@"getImages()"]
mUrlArray = [NSMutableArray arrayWithArray:[urlResurlt componentsSeparatedByString:@"+"]]
if (mUrlArray.count >= 2) {
[mUrlArray removeLastObject]
}
//urlResurlt 就是获取到得所有图片的url的拼接;mUrlArray就是所有Url的数组
//添加图片可点击js
[mWebView stringByEvaluatingJavaScriptFromString:@"function registerImageClickAction(){\
var imgs=document.getElementsByTagName('img')\
var length=imgs.length\
for(var i=0i<lengthi++){\
img=imgs[i]\
img.onclick=function(){\
window.location.href='image-preview:'+this.src}\
}\
}"]
[mWebView stringByEvaluatingJavaScriptFromString:@"registerImageClickAction()"]
}
//在这个方法中捕获到图片的点击事件和被点击图片的url
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
//预览图片
if ([request.URL.scheme isEqualToString:@"image-preview"]) {
NSString* path = [request.URL.absoluteString substringFromIndex:[@"image-preview:" length]]
path = [path stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]
//path 就是被点击图片的url
return NO
}
return YES
}