byte

问题 I have an array of bytes ( unsigned char * ) that must be converted to integer. Integers are represented over three bytes. This is what I have done //bytes array is allocated and filled //allocating space for intBuffer (uint32_t) unsigned long i = 0; uint32_t number; for(; i<size_tot; i+=3){ uint32_t number = (bytes[i]<<16) | (bytes[i+1]<<8) | bytes[i+2]; intBuffer[number]++; } This piece of code does its jobs well but it is incredibly slow due to the three accesses in memory (especially for

问题 How do I read the last n number of bytes from a file, without using RandomAccessFile. The last 6 bytes in my files contain crucial information when writing the files back. I need to write my original files, and then append the last 6 bytes elsewhere. Any guidance? Thanks 回答1: You have to do it by using RandomAccessFile. Instances of this class support both reading and writing to a random access file. A random access file behaves like a large array of bytes stored in the file system.

问题 How can I find out the number of Bytes a certain number takes up to store e.g. for \x00 - \xFF I'm looking to get 1 (Byte), \x100 - \xffff would give me 2 (Bytes) and so on. Any clue? 回答1: You can use simple math: >>> from math import log >>> def bytes_needed(n): ... if n == 0: ... return 1 ... return int(log(n, 256)) + 1 ... >>> bytes_needed(0x01) 1 >>> bytes_needed(0x100) 2 >>> bytes_needed(0x10000) 3 回答2: Unless you're dealing with an array.array or a numpy.array - the size always has

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 6 years ago . I was wondering how one would get the Text representation of a series of bytes in PHP? (Basically, the PHP version of C#'s Encoding.getString(string s) method.) I've been scouring google, and I can find how to

问题 It is possible to convert the following Student class to a binary file by writing it with ios::binary #include <fstream> #include <iostream> using namespace std; class Student{ public: char name[40], address[120], gender; double age; bool is_blabla; }; int main() { Student one; strcpy(one.name, "Cancan Can"); strcpy(one.address, "example example exampla"); one.gender = 'M'; one.age = 25; one.is_blabla = true; ofstream ofs("fifthgrade.ros", ios::binary); ofs.write((char *)&one, sizeof(one));

问题 I'm communicating over a serial port, and currently using python2 code which I want to convert to python3. I want to make sure the bytes I send over the wire are the same, but I'm having trouble verifying that that's the case. In the original code the commands are sent like this: serial.Serial().write("\xaa\xb4" + chr(2)) If I print "\xaa\xb4" in python2 I get this: ��. If I print("\xaa\xb4") in python3 I get this: ª´ Encoding and decoding seem opposite too: Python2: print "\xaa".decode(

问题 I know that if I figure this one out or if somebody shows me, it'll be a forehead slapper. Before posting any questions, I try for at least three hours and quite a bit of searching. There are several hints that are close, but nothing I have adopted/tried seems to work. I am taking a byte[] from Java and passing that via JSON (with Gson) to a python JSON using Flask. This byte[] is stored in a python object as an integer list when received, but now I need to send it to MySQLdb and store it as

问题 Working on a project utilizing byte array manipulation, I have attempted to write something like this: boolean enabled = getEnabled(); byte enabledByte = enabled ? 0x01 : 0x00; // compile error The issue that I am facing, is that the above will not compile. Type mismatch: cannot convert from int to byte However if I expand this to the following, it works without issue: boolean enabled = getEnabled(); byte enabledByte; if (enabled) { enabledByte = 0x01; } else { enabledByte = 0x00; } Leading

问题 Can someone please tell me about how to convert a thresholded image stored in a 'Bitmap' variable into a byte array and view the byte array in a text box or a text file, in C#? Can someone please help me with the code to it? i have threshoded the image using Aforge.net - link. And trying to view the byte array of it in 1s and 0s. Thank you. 回答1: If your image is Bitmap you can use LockBits and then Scan0 methods: http://msdn.microsoft.com/query/dev11.query?appId=Dev11IDEF1&l=EN-US&k=k(System

问题 I'm re-writing alibrary with a mandate to make it totally allocation free. The goal is to have 0 collections after the app's startup phase is done. Previously, there were a lot of calls like this: Int32 foo = Int32.Parse(ASCIIEncoding.ASCII.GetString(bytes, start, length)); Which I believe is allocating a string. I couldn't find a C# library function that would do the same thing automatically. I looked at the BitConverter class, but it looks like that is only if your Int32 is encoded with the