C# Parsing HTML: C# Web Parsing Solution

This is probably the most straightforward C page parsing tutorial you've ever seen!

Crawlers should know, with C parsing HTML most afraid of what? Page loading is not complete, the site anti-climbing mechanism, IP was pulled black ... This time you need a proxy IP to save the day. We do not organize those false today, directly on the dry goods.

Why do you have to use a proxy IP?

For example, you are using HtmlAgilityPack to capture e-commerce prices, and suddenly you find that all the returns are CAPTCHA pages - this is a typical IP is recognized as a crawler. At this pointExclusive proxy IP for ipipgoIt's like changing your vest to make the server think you're a normal user.

// Sample code for using the ipipgo proxy
var proxy = new WebProxy("proxy.ipipgo.com:8000", true);
var handler = new HttpClientHandler { Proxy = proxy };; var client = new HttpClient(handler);; new HttpClient(proxy)
var client = new HttpClient(handler); var html = await client.
var html = await client.GetStringAsync("Target URL"); var html = await client.GetStringAsync("Target URL"); var html = await client.

Four Steps to Practice

1. Choosing the right parse library: HtmlAgilityPack is preferred, don't get all fancy!

2. IP Pool Configuration: Get the API interface in the ipipgo backend and set the automatic switching interval

3. Masquerade request header: UserAgent should look like a real person, don't use the default value.

4. Exception handling: Change your IP address if you get a 403, don't fight it.

Old Driver's Guide to Avoiding Pitfalls

I've seen too many people planted on cookie processing, especially when using Selenium. Remember to clear the cookie every time you change your IP, otherwise it's a waste of time. ipipgo's IP survival time is recommended to be set at 5-10 minutes, which is too short to affect the efficiency, and too long to be easily recognized.

QA time

Q: What should I do if my proxy IP suddenly fails?
A: With ipipgo's smart switching mode, the system will automatically detect available IPs

Q: What should I do if I can't get up to speed on acquisition?
A: Enable ipipgo's multithreading package, use with Parallel.ForEach

Q: What should I do if I encounter dynamically loaded data?
A: WebBrowser control, but remember to work with ipipgo's residential agent is more secure!

Why ipipgo?

I've used 7 or 8 proxy providers and ended up using ipipgo for the long term for three reasons:
1. low latency of domestic nodes, measured faster than a cloud 40%
2. Support pay-per-volume, small projects do not burn money
3. Customer service is quick to respond and can be reached at 3:00 in the middle of the night

Finally, to say something out of my heart, web parsing technology itself is not difficult, the hard part is to consistently and stably obtain data. Use a good ipipgo proxy IP, with a reasonable request frequency, can save at least half of the hair. If you write the code wrongly, you can change it, but if the IP is blocked, it will be really cold.