bytearray

问题 I'm trying to convert 3 bytes to signed integer (Big-endian) in C#. I've tried to use BitConverter.ToInt32 method, but my problem is what value should have the lats byte. Can anybody suggest me how can I do it in different way? I also need to convert 5 (or 6 or 7) bytes to signed long, is there any general rule how to do it? Thanks in advance for any help. 回答1: As a last resort you could always shift+add yourself: byte b1, b2, b3; int r = b1 << 16 | b2 << 8 | b3; Just swap b1/b2/b3 until you

问题 I am having an issue with creating ImageData. I am getting the following error message: Uncaught IndexSizeError: Failed to construct 'ImageData': The input data byte length is not a multiple of (4 * width). Here is the method that I am running: public setPixelData(data: Buffer, width: number, height: number) { var imageData = new ImageData(new Uint8ClampedArray(data), width, height); this.canvas.getContext('2d').putImageData(imageData, 0, 0); } I have dumped the data and this is what is

问题 I have to send a picture to a webservice. The web service should receive the image as bytes (mayby bytearray) - not as a string... How do I convert the images to "byte" or bytearray? I have tried this (without succes): $image1 = file_get_contents("LINK TO IMAGE"); $image1BinaryData = "".base64_encode($image1).""; Any help will be appreciated... 回答1: Have you tried to directly read the image as binary data? <?php $filename = "image.png"; $file = fopen($filename, "rb"); $contents = fread($file,

问题 I have the below piece of code to convert an image to byte array. ByteArrayOutputStream baos = new ByteArrayOutputStream(); ImageIO.write(image, "png", baos); baos.flush(); byte[] imageBytes = baos.toByteArray(); baos.close(); The issue that I am facing is that the size of the image is around 2.65MB. However, imageBytes.length is giving me a value more than 5.5MB. Can somebody let me know where I am going wrong? 回答1: PNG is not always a faithful round-trip format. Its compression alghoritm

问题 I have binary string String A = "1000000110101110" . I want to convert this string into byte array of length 2 in java I have taken the help of this link I have tried to convert it into byte by various ways I have converted that string into decimal first and then apply the code to store into the byte array int aInt = Integer.parseInt(A, 2); byte[] xByte = new byte[2]; xByte[0] = (byte) ((aInt >> 8) & 0XFF); xByte[1] = (byte) (aInt & 0XFF); System.arraycopy(xByte, 0, record, 0, xByte.length);

问题 I'm trying to represent the port number 9876 (or 0x2694 in hex) in a two byte array: class foo { public static void main (String args[]) { byte[] sendData = new byte[1]; sendData[0] = 0x26; sendData[1] = 0x94; } } But I get a warning about possible loss of precision: foo.java:5: possible loss of precision found : int required: byte sendData[1] = 0x94; ^ 1 error How can I represent the number 9876 in a two byte array without losing precision? NOTE: I selected the code by @Björn as the correct

问题 Does converting from the mutable bytearray type to the non-mutable bytes type incur a copy? Is there any cost associated with it, or does the interpreter just treat it as an immutable byte sequence, like casting a char* to a const char* const in C++? ba = bytearray() ba.extend("some big long string".encode('utf-8')) # Is this conversion free or expensive? write_bytes(bytes(ba)) Does this differ between Python 3 where bytes is its own type and Python 2.7 where bytes is just an alias for str ?

问题 what are the alternative of DatatypeConverter.printHexBinary(byte[] array) and DatatypeConverter.parseHexBinary(String str) in Android. Android don't have classDef of java.xml.bind.DatatypeConverter ... 回答1: You are probably better off using the hexadecimal encoding/decoding found in the Apache commons codec library. Please make sure you are using the correct version of the library though, for more information look here 回答2: For android (gradle) dependencies just use implementation group:

问题 What is base64Binary and how can I create base64Binary from a given byte array in Java? 回答1: Try commons-codec with public static byte[] encodeBase64(byte[] binaryData) . 回答2: To create such data you may use the JDK built-in class sun.misc.BASE64Encoder. Unfortunately it's not public API since nobody cared to provide a BASE64 en-/decoder in the public API - but people often use this class to circumvent that disadvantage. base64Binary is an XML Schema data type, referring to arbitrary binary

问题 In my code i have to pass a bye array (byte[] temp = null;) to a function which is allocated and filled with data inside it. After returning from function it is still null. How can i find a solution to this problem.??? Please help me. byte[] temp = null; ret = foo(temp); boolean foo(byte[] temp) { temp = new byte[]; //fill array } 回答1: You need to use this: byte[] temp = new byte[some_const]; ret = foo(temp); boolean foo(byte[] temp) { //fill array } or byte[] temp = null; temp = foo(temp);