document.documentElement.outerHTML,這個方法是怎麽用的啊?

NSString* doc = @"document.documentElement.outerHTML";

[self.webView

evaluateJavaScript:doc

completionHandler:^(id _Nullable htmlStr, NSError* _Nullable error) {

if (error) {

NSLog(@"JSError:%@", error);

}

NSLog(@"html:%@", htmlStr);

}];