guid

问题 I have InstallShield 2013 Basic MSI project Is there an automatic way using a tool or script to automatically update all component code in the project ? 回答1: First question : why do you want to do that? A component GUID is set in stone for all absolute paths it references. See a description of this here: Change my component GUID in wix? If you are familiar with COM automation , you should be able to automate the generation of new GUIDs in your project using the Installshield automation

问题 I am trying to write a script to toggle the lid action between sleep/do nothing by using powercfg.exe and the relevant GUID. powercfg -SETACVALUEINDEX 381b4222-f694-41f0-9685-ff5bb260df2e 4f971e89-eebd-4455-a8de-9e59040e7347 5ca83367-6e45-459f-a27b-476b1d01c936 0 powercfg -SETDCVALUEINDEX 381b4222-f694-41f0-9685-ff5bb260df2e 4f971e89-eebd-4455-a8de-9e59040e7347 5ca83367-6e45-459f-a27b-476b1d01c936 0 To do nothing, and powercfg -SETACVALUEINDEX 381b4222-f694-41f0-9685-ff5bb260df2e 4f971e89

问题 A follow-up to Is there a greater chance to collide when comparing GUIDs created differently?. I have something like this: using( MD5 md5 = MD5.Create() ) { var hash = md5.ComputeHash( foo ); var hashguid = new Guid( hash ); } This guarantees the same foo will cause a GUID collision, and allows filtering of duplicates of foo . Is there any concerns that hashguid has a greater chance to collide with GUIDs generated with Guid.NewGuid() (vs. two GUIDs generated with Guid.NewGuid() )? 回答1:

问题 This question is a follow up to my previous question here: How can I convert a UUID to a string using a custom character set in Ruby? But I will try to formulate it as a separate and specific question. I do have a Ruby 128 bit UUID as hex value: SecureRandom.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594" If I get the IFC specification correctly (http://www.buildingsmart-tech.org/ifc/IFC2x3/TC1/html/ifcutilityresource/lexical/ifcgloballyuniqueid.htm), I want to Base64 encode this, but instead

问题 Is there more chance having collisions when betweens GUID's (128 bits) or SHA1 hashes of GUID's (160 bits) ? My opinion is there is less chance with a GUID (even if there is 32 bit less), because it has some special mechanisms to make sure it is (almost, because no guarantee) unique (ex : timestamp) Note : i already know that a GUID is very unlikely to have a collision with another GUID , no more debate about this please. 回答1: That's trivial: if two GUIDs are the same (that is, for each GUID

问题 Occasionally when I generate a GUID using visual studio, the 14th hex character is lowercase while the rest of the hex digits are uppercase. Cause a bit of problem when comparing the string representations of two GUIDs. Now I always compare the binary equivalents to be safe. 回答1: Yes, this is a known bug. But you shouldn't be making string comparisons; use Guid.Equals instead. 来源： https://stackoverflow.com/questions/872298/why-is-the-14th-character-in-a-guid-generated-by-visual-studio

问题 I am wondering, what goes into the creation of a GUID. I don't mean what is used to create a GUID in a specific language (NewID() in SQL Server, Guid.NewGuid() in C#), I mean when you call those methods/functions, what do they do to make the GUID? 回答1: Also, RFC 4122 (which is referenced in the Wikipedia article) describes how GUIDs should be built. 回答2: The details of GUIDs, including the algorithm used to generate them is described on wikipedia. 回答3: In short, it's not complicated at all.

问题 I've started using GUIDs over auto-increment integers for my primary keys. However, during development I'm used to querying (from SQL management studio or visual studio) database in order to see what records my application just inserted, and I'm pissed off by the fact that I cannot order by primary key desc in order to see the most recent records. Is there a way to accomplish tihs? 回答1: You can't order a GUID column based on insertion order. You'll need to rely on another column. My

问题 I have the following Guid: AAB13E97-449B-4D5B-BDE2-AC479C31B782 Using System.Guid + DbLinq + SQLite to store it the following field is added to the database. 973EB1AA-9B44-5B4D-BDE2-AC479C31B782 (Dashes added for clarity) I can see that the last 8 bytes are in the same order, and the 3 first groups are reversed, but I don't understand why. 回答1: Looking at Wikipedia's article on the subject it says: Data4 stores the bytes in the same order as displayed in the GUID text encoding (see below),

问题 I'm working with the Windows 7 audio APIs, and I've hit a wall. Basically, I need to take an IAudioSessionControl2* and get an ISimpleAudioVolume* out of it. Now, it looks like I can call on IAudioSessionManager->GetSimpleAudioVolume() using the value of IAudioSessionControl2->GetSessionInstanceIdentifier(...). Note that this isn't exactly spelled out as such in the docs, but it seems like a reasonable behavior. The problem, GetSimpleAudioVolume() takes a GUID* and