C# Crawler Library: C# Specialized Web Crawling Agent Library

I. Why is C crawler always blocked? Try this method

The data crawl brothers understand that the target site's anti-climbing mechanism is like a security patrol, catching abnormal traffic on the block IP. last week a buddy wrote a book price comparison tool with C, just run two days on the blocked a dozen IP addresses, angry at him straight cursing.

at this momentproxy IPThat's where it comes in handy! It's like wearing a mask to a costume party and changing your face every time you request, so that the anti-crawling system can't even recognize who you are. This is especially true for specialized service providers like ipipgo, which can provideMassive Residential IP Pool, the degree of camouflage is much higher than that of the server room IP.

Second, hand to teach you to choose the right agent tool library

There are quite a few crawler libraries available in the C ecosystem, but the ones optimized specifically for proxies have to be these:

For example, using HttpClient with a proxy thief is simple:

var handler = new HttpClientHandler
var handler = new HttpClientHandler
    Proxy = new WebProxy("proxy.ipipgo.io:8000")
}; var client = new HttpClient(handler)
var client = new HttpClient(handler);

Third, ipipgo real-world integration tutorials

Here's a recommendation for ipipgoDynamic Residential Agents, their IPs survive 3 times longer than normal proxies. Sign up and get the API address, dislike it directly into the code and it works:

// Automatically get the latest proxies
var proxyList = await GetProxiesFromAPI("https://api.ipipgo.com/v1/proxy");
var randomProxy = proxyList[new Random().Next(0, proxyList.Count)];

// Create the request object with the proxy
var webRequest = WebRequest.Create("Target URL");
webRequest.Proxy = new WebProxy($"{randomProxy.IP}:{randomProxy.Port}");

Be careful to set thetimeout retry mechanismThe average response time of ipipgo's proxy pool is <200ms, which is much more stable than self-built proxy servers.

IV. First aid guide to common rollover scenes

Q：Why does the agent report 407 error even though it has been configured?
A: Ninety percent of the authentication is not correct, check the username and password format is not "user:pass@ip:port".

Q: How do I verify if the agent is in effect?
A: First request http://ip.ipipgo.com/checkip to see if the returned IP is a proxy address

Q: How to handle high concurrency scenarios?
A: Use ipipgo'ssession hold functionThe same service uses a fixed IP address, while different services use different channels.

V. Why choose ipipgo and not others?

Used 7 or 8 proxy providers and ended up locking ipipgo. his family has three killer apps:

1. National coverage of real residential IP in 200+ cities
2. Automatic cleanup of failed nodes, availability 99.2%
3. Support for customized proxy strategies on demand (e.g., designated operators)

The last time I helped a client do a national house price collection, I used theirCity Location Agents, accurate access to data from all over the world, the father of the first party called it professional.

VI. Guide to avoiding pitfalls: Don't step on these mines!

I've seen people write the proxy IP to death in the configuration file, and as a result, the IP is invalidated and the whole network request hangs. The correct approach should be:

1. Dynamically obtain a new IP before each request
2. Set the number of failed retries (recommended 3)
3. Record the failed IP and feedback to the service provider

With ipipgo, their API comes with theIntelligent RoutingThe nodes are automatically filtered for unavailable nodes, saving you +10086.

One final note: Being a crawler is about afig. economy will get you a long wayDon't try to crash their servers. Reasonably set the request interval, with reliable agents, data collection can be stable for a long time.