C++ ----device-stream-boundary-- Content-Type: application/json Content-Length: 75 X-If-Encrypt: 0 {"type":"response", "seq":0, "params":{"error_code":0, "session_id":"157"}} ----device-stream-boundary-- Content-Type: image/avc X-If-Encrypt: 0 Content-Length: 4518 X-Session-Id: 157 字符串用C++代码解析出Content-Type后的字符串

可以使用C++中的字符串查找和截取函数来解析出Content-Type的值。以下是一个示例代码：

#include <iostream>
#include <string>

using namespace std;

int main() {
    string str = "----device-stream-boundary--\r\nContent-Type: application/json\r\nContent-Length: 75\r\nX-If-Encrypt: 0\r\n{\"type\":\"response\", \"seq\":0, \"params\":{\"error_code\":0, \"session_id\":\"157\"}}\r\n----device-stream-boundary--\r\nContent-Type: image/avc\r\nX-If-Encrypt: 0\r\nContent-Length: 4518\r\nX-Session-Id: 157\r\n";
    
    // 查找Content-Type字段
    size_t pos = str.find("Content-Type: ");
    if (pos != string::npos) {
        // 截取Content-Type的值
        string content_type = str.substr(pos + 14);
        size_t end_pos = content_type.find("\r\n");
        if (end_pos != string::npos) {
            content_type = content_type.substr(0, end_pos);
            cout << "Content-Type: " << content_type << endl;
        }
    }

    return 0;
}

输出结果为：

Content-Type: application/json