Question

如何通过js获取网页中所有图片并加入点击事件，实现

Answer 1

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=0;i<objs.length;i++){\
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=0;i<length;i++){\
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;
}