UINT CPublic: : Cappacketlivethread (LPVOID pParam) {
Struct pcap_pkthdr * header; Packet header information/* */
Const u_char * pkt_data;//data 
M_pacNum=0;//to capture the number of packages 
CFile m_file; 
If (m_file. Open (_T (" default. DAT "), CFile: : modeRead, NULL))//temporary files 
{
M_file. Close (); 
M_file. Remove (_T (" default. DAT ")); 
} 
M_filepath="default. DAT"; 
Dumpfile=pcap_dump_open (adhandle m_filepath); 
Int res=0; 
//when the user press the start button and start to capture 
While (res=(pcap_next_ex (adhandle, & amp; The header, & amp; Pkt_data) & gt;=0 & amp; & IsStart) {
If (res==0) continue; 
+ + m_pacNum; 
Pcap_dump ((u_char *) dumpfile, header, pkt_data); 
} 
return 0; 
} 

This is my caught threads, caught in the beginning, res value is 1, but the header and pkt_data display results as shown in the figure below:

This is how to return a responsibility?