The UDP File Sending function in xcode, which is used to send 8000 bytes per packet.

-(Void) udp_sendfile :( nsstring *) filename;

{

Nsstring * filepath = [nstemporarydirectory () stringbyappendingstring: Filename];

Nsdata * sdata = [[nsdata alloc] initwithcontentsoffile: filepath];

Byte * Sarr;

Int sumpak, curpak;

// Subpacket Transmission

Int Total = sdata. length, curloc, srctotal = sdata. length;

Sumpak = srctotal/8000;

If (srctotal % 8000 = 0)

{

}

Else

{

Sumpak = sumpak + 1;

}

Curpak = 0;

Curloc = 0;

Nslog (@ "Total: % d", total );

// File Information header: Ea filetype paknum1 paknum2 paknum2 paknum3 paksum1 paksum2 paksum3 paksum4 datalen1 datalen2 CHK1 CHK2 temp

While (total> 8000)

{

Curpak ++;

Nsdata * pdata = [sdata subdatawithrange: nsmakerange (curloc, 8000)];

Sarr = new byte [8016];

Byte * bytes;

Sarr [0] = 0xea; // header flag

Sarr [1] = 0xea; // header flag

Sarr [2] = 0; // file type

Sarr [3] = curpak/256/256/256; // Package number

Sarr [4] = curpak % (256*256*256)/256;

Sarr [5] = curpak % (256*256)/256;

Sarr [6] = curpak % (256*256) % 256;

Sarr [7] = sumpak/256/256/256; // Total number of packages

Sarr [8] = sumpak % (256*256*256)/256;

Sarr [9] = sumpak % (256*256)/256;

Sarr [10] = sumpak % (256*256) % 256;

Sarr [11] = 8000/256;

Sarr [12] = 8000% 256;

Int check = 0;

Bytes = (byte *) [pdata bytes];

For (INT I = 0; I <8000; I ++)

{

Check = check + bytes [I];

Sarr [I + 16] = bytes [I];

}

Sarr [13] = check/256;

Sarr [14] = check % 256;

Sarr [15] = 0;

Nsdata * sdata = [[nsdata alloc] initwithbytes: Sarr length: 8016];

[Udpclient senddata: sdata tohost: serverip port: 8009 withtimeout: 5000 Tag: 1];

Total = total-8000;

Curloc = fig + 8000;

Sarr = nil;

Nslog (@ "% d", 8000 );

}

If (total> 0)

{

Curpak ++;

Nsdata * pdata = [sdata subdatawithrange: nsmakerange (curloc, total)];

Sarr = new byte [Total + 16];

Byte * bytes = (byte *) [pdata bytes];

Sarr [0] = 0xea; // header flag

Sarr [1] = 0xea; // header flag

Sarr [2] = 0; // file type

Sarr [3] = curpak/256/256/256; // Package number

Sarr [4] = curpak % (256*256*256)/256;

Sarr [5] = curpak % (256*256)/256;

Sarr [6] = curpak % (256*256) % 256;

Sarr [7] = sumpak/256/256/256; // Total number of packages

Sarr [8] = sumpak % (256*256*256)/256;

Sarr [9] = sumpak % (256*256)/256;

Sarr [10] = sumpak % (256*256) % 256;

Sarr [11] = 8000/256;

Sarr [12] = 8000% 256;

Int check = 0;

For (INT I = 0; I <total; I ++)

{

Check = check + bytes [I];

Sarr [I + 16] = bytes [I];

}

Sarr [13] = check/256;

Sarr [14] = check % 256;

Sarr [15] = 0;

Nsdata * sdata = [[nsdata alloc] initwithbytes: Sarr length: Total + 16];

[Udpclient senddata: sdata tohost: serverip port: 8009 withtimeout: 5000 Tag: 1];

Nslog (@ "% d", total );

 

}

 

}