byte

问题 I don't understand why the lowest value a byte can take is -128 . I can see that the highest value is 127 , because it's 01111111 in binary, but how does one represent -128 with only 8 bits, one of which is used for the sign? Positive 128 would already be 8-bit, i.e. 10000000 , and then you would need a 9th bit to represent the negative sign. Could someone please help explain this to me. 回答1: The answer is two's complement. In short, Java (and most modern languages) do not represent signed

问题 I need to convert a simple string to a byte array which uses hex representation, just like that site: http://string-functions.com/string-hex.aspx This string then gets send via bluetooth using python and the arduino reads the individual bytes like this: char buff[1000]; int i =0; int typeByte = serial->read(); int data = serial->read(); while (true) { if (data == -1) continue; if (data == 254 || data == 10) break; buff[i++] = data; data = serial->read(); delay(10); } String buffer(buff); if

问题 I need to convert a simple string to a byte array which uses hex representation, just like that site: http://string-functions.com/string-hex.aspx This string then gets send via bluetooth using python and the arduino reads the individual bytes like this: char buff[1000]; int i =0; int typeByte = serial->read(); int data = serial->read(); while (true) { if (data == -1) continue; if (data == 254 || data == 10) break; buff[i++] = data; data = serial->read(); delay(10); } String buffer(buff); if

问题 C# code byte[] array = bytes.Take<byte>(num).ToArray<byte>(); VB.NET Converted Code (i tried multiable ones. same result) Dim array As Byte() = bytes.Take(Of Byte)(num).ToArray(Of Byte)() got an error on : (of Byte) Error Extension method 'Public Function Take(count As Integer) As System.Collections.Generic.IEnumerable(Of TSource)' defined in 'System.Linq.Enumerable' is not generic (or has no free type parameters) and so cannot have type arguments 回答1: I don't have much experience with this,

问题 i usualy set my byte[] arrays like this: byte[] byteArr = { 123, 234, 123, 234, 123, 123, 234 }; now, my problem, i am getting the datas that have to be stored into the array as a string. example: string datas = "123, 234, 123, 234, 123, 123, 234"; i would like to do something like: byte[] byteArr = { datas }; with no luck... I tried exploding the string to array of strings, then convert each value to Int before storing into each array field. with no luck: for (var i = O; i<datasArray.length;

问题 I'm playing with the code snippet from this original question: Read bytes from a binary file with JavaScript, without jQuery However, for some reasons, a whole different set of bytes appear to be loaded! I suspect this has to do with the string conversion. Here's a copy of the binary file I am trying to download: http://steeman.dk/html5/coco/colorbasic13.rom To my local IIS 7.5 server I have added the .rom MIME type as 'application/octet-stream' (I have also tried with 'text/plain; charset=x

问题 I have to send a byte array to an api along with the field data as shown in the figure.I have a doubt about using the modules provided by angularjs community because its not stating about how the data is transferred and I have little understanding about it. so I want to post any file uploaded from a button to a byte collection to an api with the form data. here is an image for my api. Actually the problem I faced is changing the file to byte in angular and again finding a module to upload the

问题 I have to send a byte array to an api along with the field data as shown in the figure.I have a doubt about using the modules provided by angularjs community because its not stating about how the data is transferred and I have little understanding about it. so I want to post any file uploaded from a button to a byte collection to an api with the form data. here is an image for my api. Actually the problem I faced is changing the file to byte in angular and again finding a module to upload the

问题 How to find size in byte of 50 x 50 RGB color image? If the above image saved in BMP file with 54 bytes of header size, what is the total size of that BMP file? How to know the content of every bytes in BMP file? And how to know the hexadecimal value of it? 回答1: Assuming you mean in-memory requirements, the minimum amount of memory needed would be 50 * 50 * 3 ( width * height * numComponents ), or 7500 bytes for RGB. However, it might be faster to pad each scanline, for example to an even

问题 I am having problems of conversion through string->byte->byte[] What I have done so far: double db = 1.00; double ab = db*100; int k = (int) ab; String aa = String.format("%06d", k); String first = aa.substring(0,2);`` String second = aa.substring(2,4); String third = aa.substring(4,6); String ff = "0x"+first; String nn = "0x"+second; String yy = "0x"+third; I want to write those bytes to an byte[]. What I mean is: byte[] bytes = new byte[]{(byte) 0x02, (byte) 0x68, (byte) 0x14, (byte) 0x93,