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Duplicate returned by Guid.NewGuid()?

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问题 We have an application that generates simulated data for one of our services for testing purposes. Each data item has a unique Guid. However, when we ran a test after some minor code changes to the simulator all of the objects generated by it had the same Guid. There was a single data object created, then a for loop where the properties of the object were modified, including a new unique Guid, and it was sent to the service via remoting (serializable, not marshal-by-ref, if that's what you're

When would you use GUIDs as primary keys? [duplicate]

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问题 This question already has answers here : Closed 10 years ago . Possible Duplicate: Advantages and disadvantages of GUID / UUID database keys Are there any circumstances where it is essential to use GUIDs as primary keys in a SQL Server 2005/8 DB. For example, does the use of the MS Sync Framework force this, or data replication? 回答1: You would use guids as a key if you needed multiple databases synchronising via replication. Another reason to use guids is if you wanted to create rows on some

Revit二次开发DockableDialog (可停靠窗体)

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三个步骤 1、首先可停靠窗体为 Page 窗体，即WPF控件需继承自Page。此外还需继承 IDockablePaneProvider 接口，然后在WPF控件后台代码汇总实现函数SetupDockablePane。 2、在IExternalApplication的OnStartup函数中完成注册（RegisterDockablePane）可停靠窗口，同时添加一个Revit命令按钮。 3、在IExternalCommand里调用Page窗口， uiapp.GetDockablePane(dockablepaneid)，然后dockablepane.Show()。注：如果想要实现在Revit里选择一个构件，然后在可停靠窗口里显示一些信息，可以用空闲事件来实现。代码如下： <Page x:Class="DockableDialogsTest.UserControl1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http:/

Is there a GUID.TryParse() in .NET 3.5?

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问题 UPDATE Guid.TryParse is available in .NET 4.0 END UPDATE Obviously there is no public GUID.TryParse() in .NET CLR 2.0. So, I was looking into regular expressions [aka googling around to find one] and each time I found one there was a heated argument in the comments section about RegEx A doesn't work, use RegEx B. Then someone would write Regex C yadda yadda So anyway, What I decided to do was this, but I feel bad about it. public static bool IsGuid (string possibleGuid) { try { Guid gid = new

Guid.Parse() or new Guid() - What's the difference?

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问题 What is the difference between these two ways of converting a string to System.Guid ? Is there a reason to choose one over the other? var myguid = Guid.Parse("9546482E-887A-4CAB-A403-AD9C326FFDA5"); or var myguid = new Guid("9546482E-887A-4CAB-A403-AD9C326FFDA5"); 回答1: A quick look in the Reflector reveals that both are pretty much equivalent. public Guid(string g) { if (g == null) { throw new ArgumentNullException("g"); } this = Empty; GuidResult result = new GuidResult(); result.Init

Is the format of GUID always the same?

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问题 GUID you get something like aaaef973-d8ce-4c92-95b4-3635bb2d42d5 Is it always the same? Is it always going to have the following format 8 char "-", 4 char "-", 4 char "-", 4 char "-", 12 char I'm asking because i need to convert a GUID without "-" to GUID with "-" and vice visa. 回答1: No; there are other formats, such as the format you listed except with braces. There's also more complex formats. Here are some of the formats MSDN lists: UUID formats 32 digits: 00000000000000000000000000000000

Oracle SYS_GUID does not change

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问题 I have an Oracle project that would be a good fit for using GUIDs as a key. I found the following snippet SET SERVEROUTPUT ON BEGIN FOR indx IN 1 .. 5 LOOP DBMS_OUTPUT.put_line ( SYS_GUID ); END LOOP; END; / From http://feuerthoughts.blogspot.com/2006/02/watch-out-for-sequential-oracle-guids.html When I run it against my database (I tried it on versions 10g and version 11) I get output like 64FE4083D6BA7CB4E0400F0A0E0A18B0 64FE4083D6BB7CB4E0400F0A0E0A18B0 64FE4083D6BC7CB4E0400F0A0E0A18B0

Cannot embed interop types from assembly “…\Microsoft.Search.Interop.dll” because it is missing the GuidAttribute attribute

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问题 I get this error when adding a reference to the Microsoft.Search.Interop.dll library in a new project that I created. Microsoft.Search.Interop.dll is a library that provides some useful API to communicate with Windows Search. I use it in order to add a folder to the system indexer. Did anybody else get this error, and if so, how should I go about solving it? I'm using VS2010 RC on a Windows Server 2008 if that is important. 回答1: Go to the Properties window for Microsoft.Search.Interop and

Are GUIDs timely ordered ? If ORDER BY used with a GUID variable type, will records created lately come late?

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问题 Are GUIDs timely ordered ? I mean if you use ORDER BY with a GUID variable type, will records created lately come late ? 回答1: A simple LINQPad mockup answers your question: var dictionary = new Dictionary<int, Guid>(); for (int i = 0; i < 5; i++) dictionary.Add(i, Guid.NewGuid()); dictionary.OrderBy(d => d.Value); Results in: Key Value 2 3624183d-581a-45bc-9d3d-cafeddaf8585 0 4b4685c9-f163-4694-ae8c-4b83402a293c 4 7a14d8e4-d870-4f33-bfb3-f4337b756e18 1 b93131c7-c0d7-42b4-82b5-e3cc456214a9 3

Different casting of int to guid in C# and SQL Server

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问题 When converting int to guid in C# and SQL Server I get different values. In C# I use this method public static Guid Int2Guid( int value ) { byte[] bytes = new byte[16]; BitConverter.GetBytes( value ).CopyTo( bytes, 0 ); return new Guid( bytes ); } Console.Write( Int2Guid( 1000 ).ToString() ); // writes 000003e8-0000-0000-0000-000000000000 In SQL Server I use select cast(cast(1000 as varbinary(16)) as uniqueidentifier) -- writes E8030000-0000-0000-0000-000000000000 Why would they behave