c++ 中的while true 跳出循环try
时间: 2023-09-09 09:08:04 浏览: 50
在 C++ 中,可以使用 "try-catch" 语句来捕获异常并跳出 "while true" 循环。例如:
```
while (true) {
try {
// 循环体代码
if (condition) {
throw "some exception"; // 抛出异常
}
} catch (...) {
// 捕获异常并跳出循环
break;
}
}
```
在循环体中如果抛出了异常,"catch" 语句会捕获到异常并执行相应的代码块,这里使用 "break" 语句来跳出 "while true" 循环。需要注意的是,"catch" 语句中的 "..." 表示捕获任何类型的异常,你也可以指定捕获特定类型的异常。
相关问题
c++中实现websocket客户端和服务端
在C++中实现WebSocket客户端和服务端,通常需要使用第三方库来简化操作。以下是使用两个流行的C++ WebSocket库的示例代码:
1. 使用Boost.Beast库实现WebSocket客户端和服务端:
WebSocket客户端:
```c++
#include <boost/beast/core.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/asio/connect.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <iostream>
namespace beast = boost::beast;
namespace http = beast::http;
namespace websocket = beast::websocket;
namespace net = boost::asio;
using tcp = boost::asio::ip::tcp;
int main(int argc, char** argv) {
net::io_context ioc;
tcp::resolver resolver(ioc);
websocket::stream<tcp::socket> ws(ioc);
auto const results = resolver.resolve("echo.websocket.org", "80");
boost::asio::connect(ws.next_layer(), results.begin(), results.end());
ws.handshake("echo.websocket.org", "/");
ws.write(net::buffer(std::string("Hello, world!")));
beast::flat_buffer buffer;
ws.read(buffer);
std::cout << beast::make_printable(buffer.data()) << std::endl;
ws.close(websocket::close_code::normal);
}
```
WebSocket服务端:
```c++
#include <boost/beast/core.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <iostream>
namespace beast = boost::beast;
namespace http = beast::http;
namespace websocket = beast::websocket;
namespace net = boost::asio;
using tcp = boost::asio::ip::tcp;
int main(int argc, char** argv) {
net::io_context ioc;
tcp::acceptor acceptor(ioc, tcp::endpoint(tcp::v4(), 8080));
while (true) {
tcp::socket socket(ioc);
acceptor.accept(socket);
try {
websocket::stream<tcp::socket> ws(std::move(socket));
ws.accept();
beast::flat_buffer buffer;
ws.read(buffer);
ws.text(ws.got_text());
ws.write(buffer.data());
} catch (const std::exception& e) {
std::cerr << "Error: " << e.what() << std::endl;
}
}
}
```
2. 使用Simple-Websocket-Server库实现WebSocket客户端和服务端:
WebSocket客户端:
```c++
#include "websocket.h"
int main(int argc, char** argv) {
auto client = std::make_shared<SimpleWeb::SocketClient<SimpleWeb::WS>>();
client->on_open = [](std::shared_ptr<SimpleWeb::SocketClient<SimpleWeb::WS>> client) {
std::cout << "Connected to server!" << std::endl;
client->send("Hello, world!");
};
client->on_message = [](std::shared_ptr<SimpleWeb::SocketClient<SimpleWeb::WS>> client, std::shared_ptr<SimpleWeb::WS::Message> message) {
std::cout << "Received message: " << message->string() << std::endl;
client->close();
};
client->connect("echo.websocket.org", 80);
}
```
WebSocket服务端:
```c++
#include "websocket.h"
int main(int argc, char** argv) {
auto server = std::make_shared<SimpleWeb::SocketServer<SimpleWeb::WS>>();
server->on_message = [](std::shared_ptr<SimpleWeb::SocketServer<SimpleWeb::WS>::Connection> connection, std::shared_ptr<SimpleWeb::WS::Message> message) {
std::cout << "Received message: " << message->string() << std::endl;
connection->send(message->string());
};
server->start();
}
```
请注意,这只是WebSocket客户端和服务端实现的基本示例。使用时需要根据实际需求进行修改和扩展。
c++中http服务 asio库使用案例
下面是一个简单的使用 Boost.Asio 库实现 HTTP 服务器的示例代码:
```cpp
#include <iostream>
#include <boost/asio.hpp>
using boost::asio::ip::tcp;
std::string make_http_response()
{
return "HTTP/1.1 200 OK\r\nContent-Length: 13\r\n\r\nHello, World!";
}
int main()
{
try
{
boost::asio::io_context io_context;
tcp::acceptor acceptor(io_context, tcp::endpoint(tcp::v4(), 8080));
std::cout << "HTTP server started. Listening on port 8080." << std::endl;
while (true)
{
tcp::socket socket(io_context);
acceptor.accept(socket);
std::cout << "Client connected." << std::endl;
boost::system::error_code error;
// 发送 HTTP 响应给客户端
boost::asio::write(socket, boost::asio::buffer(make_http_response()), error);
if (error)
{
std::cerr << "Error sending HTTP response: " << error.message() << std::endl;
}
}
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << std::endl;
}
return 0;
}
```
该代码实现了一个简单的 HTTP 服务器,监听本地 8080 端口,并在有客户端连接时发送 "Hello, World!" 的 HTTP 响应。可以使用浏览器或其他 HTTP 客户端访问该服务器来查看响应。