uniqueidentifier

问题 The OpenGL tradition is to let the user manipulate OpenGL objects using an unsigned int handle. Why not just give a pointer instead? What are the advantages of unique IDs over pointers? 回答1: TL;DR: OpenGL IDs don't map bijectively to memory locations. A single OpenGL ID may refer to multiple memory locations at the same time. Also OpenGL has been designed to work for distributed rendering architectures (like X11) as well, and given an indirect context programs running on different machines

问题 I want to create a unique Id with reset button. I have a class ViewId . ViewId class contain AtomicInteger . AtomicInteger create unique Id successfully.But I want to reset unique Id using a button.So please help me to reset and create unique id again. ViewId Class : import java.util.concurrent.atomic.AtomicInteger; public class ViewId { private static ViewId INSTANCE = new ViewId(); private AtomicInteger seq; private ViewId() { seq = new AtomicInteger(0); } public int getUniqueId() { return

问题 I create a new project based on cocos2d-box2d, and there are always 4 warning in two files, one is CLScoreServerPost.m, the code has warning is following [self addValue:[[UIDevice currentDevice] uniqueIdentifier] key:@"cc_device_id"]; and another is CLScoreServerRequest.m, the code has warning is following device = [[UIDevice currentDevice] uniqueIdentifier]; both of them show the same warning: 'uniqueIdentifier' is deprecated so what should I do? many thanks 回答1: You can use for example

问题 In iOS 6, [UIDevice currentDevice].identifierForVendor provides a unique ID across all the apps from a single vendor. Is there any way to do the same thing in Android? 回答1: There is the Android Id: Generating Device-Specific Serial Number Note that Android is designed so you can't automatically get a full device id. Android even modified a pre-existing part of linux that would have made this possible. Even better than Android id: your app can request the AUTHENTICATE_ACCOUNTS permission. Then

问题 Play framework creates an Id for Entities which extend the model class as such: @MappedSuperclass public class Model extends GenericModel { @Id @GeneratedValue public Long id; public Long getId() { return id; } @Override public Object _key() { return getId(); } } Is it possible to use this id (max id) to determine the latest created record? I want to make some jobs rerunnable from a certain point in the event of failures and this would be by far the easiest way to add this functionality. I do

问题 I would like to have a class which, in its constructor, can have knowledge (extract as a string) its instance name. For the moment I worked the name extraction out like this: classdef mysession methods (Access = public) function this=mysession (varargin) this.cargs=varargin; this.built=false; end function id=build(this) id=this.mynameis; this.id = id; %% instructions needing id built=true; end function name = mynameis (this) name=evalin ('caller', 'inputname'); end end properties (Access

问题 I have a junction table in my SQL Server 2005 database that consist of two columns: object_id (uniqueidentifier) property_id (integer) These values together make a compound primary key. What's the best way to create this PK index for SELECT performance? If the columns were two integers, I would just use a compound clustered index (the default). However, I've heard bad things about clustered indexes when uniqueidentifiers are involved. Anyone have experience with this situation? 回答1: Yes, GUID

问题 I want to generate 64 bits long int to serve as unique ID's for documents. One idea is to combine the user's ID, which is a 32 bit int, with the Unix timestamp, which is another 32 bits int, to form an unique 64 bits long integer. A scaled-down example would be: Combine two 4-bit numbers 0010 and 0101 to form the 8-bit number 00100101 . Does this scheme make sense? If it does, how do I do the "concatenation" of numbers in Python? 回答1: Left shift the first number by the number of bits in the

问题 The problem is as follows - there's a university campus wide wifi connection with a single SSID, say "campus-wifi". The user freely roams around campus, and the usual hand-off between access points occurs. My question is, is there any information at any layer of the network stack that allows the client to identify (any unique identifier is fine) the specific access point they're connected to, rather than simply the fact that they are connected to "campus-wifi"? If it's relevant, I'd like to

问题 I need to generate unique record id for the given unique string. I tried using uuid format which seems to be good. But we feel that is lengthly. so we need to cutdown the uuid string 9f218a38-12cd-5942-b877-80adc0589315 to smaller. By removing '-' we can save 4 chars. What is the safest part to remove from uuid? We don't need universally unique id but we like to use uuid as a source but cut down strings. We need unique id specific to site/database (SQL Server/ADO.NET Data services). Any idea