How to downloaded a JPEG image from server? I use the collowing
statements:
using (Stream stream = web.OpenRead(link)) {
long len = -1;
bool ok = true;
string s = web.ResponseHeaders["Content-Type"];
if (s != null && s != "image/jpeg")
ok = false;
s = web.ResponseHeaders["Content-Length"];
if (s != null)
len = int.Parse(s);
if (ok && (len == -1 || len 4)) {
using (StreamReader sr = new StreamReader(stream)) {
int HEADER = 6;
sr.Read(buffer, 4, HEADER);
1 >>>
//if (buffer[0] == 0xFF &&
// buffer[1] == 0xD8 &&
// buffer[2] == 0xFF &&
// buffer[3] == 0xE0) {
if (buffer[4] == 0x00 &&
buffer[5] == 0x10 &&
buffer[6] == 0x4A &&
buffer[7] == 0x46 &&
buffer[8] == 0x49 &&
buffer[9] == 0x46) {
// download
HEADER += 4;
2 >>>
buffer[0] = (char) 0xFF;
buffer[1] = (char) 0xD8;
buffer[2] = (char) 0xFF;
buffer[3] = (char) 0xE0;
int dloaded = sr.Read(buffer, HEADER, bufferSize -
HEADER);
dloaded += HEADER;
using (StreamWriter sw = new StreamWriter(fname)) {
while (true) {
sw.Write(buffer, 0, dloaded);
if (dloaded != bufferSize) break;
dloaded = sr.Read(buffer, 0, bufferSize);
}
sw.Close();
}
....
The response stream does not seem to contain (1) the Start Of Image
(FF D8) and JFIF (FF E0) markers! So I cannot save the stream directly
to disk. That's what's the (2) hack for, but it does not write the
given bytes, for example instead of FF it writes C3 BF. I guess it's
due to Unicode but I don't know how to make it work. sw.Write does not
support writing bytes.
Similarly, the stream does not contain End Of Image (FF D9) marker.
What else is it missing?
Lukasz
