Guid Structure
Represents a globally unique identifier (GUID).
Assembly: mscorlib (in mscorlib.dll)
The Guid type exposes the following members.
Name | Description | |
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Guid(Byte[]) | Initializes a new instance of the Guid structure using the specified array of bytes. | |
Guid(String) | Initializes a new instance of the Guid structure using the value represented by the specified string. | |
Guid(Int32, Int16, Int16, Byte[]) | Initializes a new instance of the Guid structure using the specified integers and byte array. | |
Guid(Int32, Int16, Int16, Byte, Byte, Byte, Byte, Byte, Byte, Byte, Byte) | Initializes a new instance of the Guid structure using the specified integers and bytes. | |
Guid(UInt32, UInt16, UInt16, Byte, Byte, Byte, Byte, Byte, Byte, Byte, Byte) | Initializes a new instance of the Guid structure using the specified unsigned integers and bytes. |
Name | Description | |
---|---|---|
CompareTo(Guid) | Compares this instance to a specified Guid object and returns an indication of their relative values. | |
CompareTo(Object) | Compares this instance to a specified object and returns an indication of their relative values. | |
Equals(Guid) | Returns a value indicating whether this instance and a specified Guid object represent the same value. | |
Equals(Object) | Returns a value that indicates whether this instance is equal to a specified object. (Overrides ValueType.Equals(Object).) | |
Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) | |
GetHashCode | Returns the hash code for this instance. (Overrides ValueType.GetHashCode().) | |
GetType | Gets the Type of the current instance. (Inherited from Object.) | |
MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) | |
NewGuid | Initializes a new instance of the Guid structure. | |
Parse | Converts the string representation of a GUID to the equivalent Guid structure. | |
ParseExact | Converts the string representation of a GUID to the equivalent Guid structure, provided that the string is in the specified format. | |
ToByteArray | Returns a 16-element byte array that contains the value of this instance. | |
ToString() | Returns a string representation of the value of this instance in registry format. (Overrides ValueType.ToString().) | |
ToString(String) | Returns a string representation of the value of this Guid instance, according to the provided format specifier. | |
ToString(String, IFormatProvider) | Returns a string representation of the value of this instance of the Guid structure, according to the provided format specifier and culture-specific format information. | |
TryParse | Converts the string representation of a GUID to the equivalent Guid structure. | |
TryParseExact | Converts the string representation of a GUID to the equivalent Guid structure, provided that the string is in the specified format. |
Name | Description | |
---|---|---|
Equality | Indicates whether the values of two specified Guid objects are equal. | |
Inequality | Indicates whether the values of two specified Guid objects are not equal. |
Name | Description | |
---|---|---|
IFormattable.ToString | Returns a string representation of the value of this instance, according to the provided format specifier and culture-specific format information. |
The following example uses the System.Runtime.InteropServices.GuidAttribute class to assign a GUID to a user-defined class and an interface. It retrieves the value of the GUID by calling the GetCustomAttribute method and compares it with two other GUIDs to determine whether they are equal.
using System; using System.Runtime.InteropServices; // Guid for the interface IMyInterface. [Guid("F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4")] interface IMyInterface { void MyMethod(); } // Guid for the coclass MyTestClass. [Guid("936DA01F-9ABD-4d9d-80C7-02AF85C822A8")] public class MyTestClass : IMyInterface { public void MyMethod() {} public static void Main( string []args ) { GuidAttribute IMyInterfaceAttribute = (GuidAttribute) Attribute.GetCustomAttribute(typeof(IMyInterface), typeof(GuidAttribute)); // The Value property of GuidAttribute returns a string. System.Console.WriteLine("IMyInterface Attribute: " + IMyInterfaceAttribute.Value ); // Using the string to create a guid. Guid myGuid1 = new Guid(IMyInterfaceAttribute.Value ); // Using a byte array to create a guid. Guid myGuid2 = new Guid(myGuid1.ToByteArray()); // Equals is overridden to perform a value comparison. if (myGuid1.Equals(myGuid2)) System.Console.WriteLine("myGuid1 equals myGuid2"); else System.Console.WriteLine("myGuid1 does not equal myGuid2" ); // Equality operator can also be used to determine if two guids have same value. if ( myGuid1 == myGuid2 ) System.Console.WriteLine( "myGuid1 == myGuid2" ); else System.Console.WriteLine( "myGuid1 != myGuid2" ); } } // The example displays the following output: // IMyInterface Attribute: F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4 // myGuid1 equals myGuid2 // myGuid1 == myGuid2
Note that the GuidAttribute is typically used in an application to expose a type to COM. If you compile this example, you can run Regasm.exe on the generated assembly to create .reg file and .tlb files. The .reg file can be used to register the coclass in the registry, and the .tlb file can provide metadata for COM interop.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.