dotnet · BillWagner · Feb 17, 2022 · Feb 16, 2022
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+module ctor1
+
+// <Snippet1>
+open System
+
+let guidStrings =
+    [ "ca761232ed4211cebacd00aa0057b223"
+      "CA761232-ED42-11CE-BACD-00AA0057B223"
+      "{CA761232-ED42-11CE-BACD-00AA0057B223}"
+      "(CA761232-ED42-11CE-BACD-00AA0057B223)"
+      "{0xCA761232, 0xED42, 0x11CE, {0xBA, 0xCD, 0x00, 0xAA, 0x00, 0x57, 0xB2, 0x23}}" ]
+
+for guidString in guidStrings do
+    let guid = Guid guidString
+    printfn $"Original string: {guidString}"
+    printfn $"Guid:            {guid}\n"
+
+// The example displays the following output:
+//    Original string: ca761232ed4211cebacd00aa0057b223
+//    Guid:            ca761232-ed42-11ce-bacd-00aa0057b223
+//
+//    Original string: CA761232-ED42-11CE-BACD-00AA0057B223
+//    Guid:            ca761232-ed42-11ce-bacd-00aa0057b223
+//
+//    Original string: {CA761232-ED42-11CE-BACD-00AA0057B223}
+//    Guid:            ca761232-ed42-11ce-bacd-00aa0057b223
+//
+//    Original string: (CA761232-ED42-11CE-BACD-00AA0057B223)
+//    Guid:            ca761232-ed42-11ce-bacd-00aa0057b223
+//
+//    Original string: {0xCA761232, 0xED42, 0x11CE, {0xBA, 0xCD, 0x00, 0xAA, 0x00, 0x57, 0xB2, 0x23}}
+//    Guid:            ca761232-ed42-11ce-bacd-00aa0057b223
+// </Snippet1>
@@ -0,0 +1,11 @@
+module ctor2
+
+// <Snippet2>
+open System
+
+let g = Guid(0xA, 0xBs, 0xCs, [| 0uy..7uy |])
+printfn $"{g:B}"
+
+// The example displays the following output:
+//        {0000000a-000b-000c-0001-020304050607}
+// </Snippet2>
@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="ctor1.fs" />
+    <Compile Include="ctor2.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,32 @@
+module compareto1
+
+// <Snippet2>
+open System
+open System.Runtime.InteropServices
+
+[<Guid("936DA01F-9ABD-4d9d-80C7-02AF85C822A8")>]
+type Example = class end
+
+let guidAttr = 
+    Attribute.GetCustomAttribute(typeof<Example>, typeof<GuidAttribute>) :?> GuidAttribute
+
+let guidValue = 
+    Guid.Parse guidAttr.Value
+
+let values: obj[] =
+    [| null; 16 
+       Guid.Parse "01e75c83-c6f5-4192-b57e-7427cec5560d"
+       guidValue |]
+
+for value in values do
+    try
+        printfn $"{guidValue} and %A{value}: {guidValue.CompareTo value}"
+    with :? ArgumentException ->
+        printfn $"Cannot compare {guidValue} and %A{value}"
+
+// The example displays the following output:
+//    936da01f-9abd-4d9d-80c7-02af85c822a8 and <null>: 1
+//    Cannot compare 936da01f-9abd-4d9d-80c7-02af85c822a8 and 16
+//    936da01f-9abd-4d9d-80c7-02af85c822a8 and 01e75c83-c6f5-4192-b57e-7427cec5560d: 1
+//    936da01f-9abd-4d9d-80c7-02af85c822a8 and 936da01f-9abd-4d9d-80c7-02af85c822a8: 0
+// </Snippet2>
@@ -0,0 +1,24 @@
+module compareto2
+
+// <Snippet1>
+open System
+
+type Comparison =
+    | ``Less Than`` = -1
+    | Equals = 0
+    | ``Greater Than`` = 1
+
+let mainGuid = 
+    Guid.Parse "01e75c83-c6f5-4192-b57e-7427cec5560d"
+
+let guid2 = Guid(0x01e75c83, 0xc6f5s, 0x4192s, [| 0xb5uy; 0x7euy; 0x74uy; 0x27uy; 0xceuy; 0xc5uy; 0x56uy; 0x0cuy |])
+let guid3 = 
+    Guid.Parse("01e75c84-c6f5-4192-b57e-7427cec5560d")
+
+printfn $"{mainGuid} {mainGuid.CompareTo guid2 |> enum<Comparison> :F} {guid2}"
+printfn $"{mainGuid} {mainGuid.CompareTo guid3 |> enum<Comparison> :F} {guid3}"
+
+// The example displays the following output:
+//    01e75c83-c6f5-4192-b57e-7427cec5560d Greater Than 01e75c83-c6f5-4192-b57e-7427cec5560c
+//    01e75c83-c6f5-4192-b57e-7427cec5560d Less Than 01e75c84-c6f5-4192-b57e-7427cec5560d
+// </Snippet1>
@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="compareto1.fs" />
+    <Compile Include="compareto2.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,21 @@
+// <Snippet1>
+open System
+
+// Create a GUID and determine whether it consists of all zeros.
+let guid1 = Guid.NewGuid()
+printfn $"{guid1}"
+printfn $"Empty: {guid1 = Guid.Empty}\n"
+
+// Create a GUID with all zeros and compare it to Empty.
+let bytes = Array.zeroCreate<byte> 16
+let guid2 = Guid bytes
+printfn $"{guid2}"
+printfn $"Empty: {guid2 = Guid.Empty}"
+
+// The example displays output like the following:
+//       11c43ee8-b9d3-4e51-b73f-bd9dda66e29c
+//       Empty: False
+//
+//       00000000-0000-0000-0000-000000000000
+//       Empty: True
+// </Snippet1>
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="empty.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="ng.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,12 @@
+//<snippet1>
+open System
+
+// Create and display the value of two GUIDs.
+let g = Guid.NewGuid()
+printfn $"{g}"
+printfn $"{Guid.NewGuid()}"
+
+// This code example produces a result similar to the following:
+//     0f8fad5b-d9cb-469f-a165-70867728950e
+//     7c9e6679-7425-40de-944b-e07fc1f90ae7
+//</snippet1>
@@ -0,0 +1,41 @@
+//<Snippet1>
+open System
+open System.Runtime.InteropServices
+
+// Guid for the interface IMyInterface.
+[<Guid "F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4">]
+type IMyInterface =
+    abstract MyMethod: unit -> unit
+
+// Guid for the coclass MyTestClass.
+[<Guid "936DA01F-9ABD-4d9d-80C7-02AF85C822A8">]
+type MyTestClass() =
+    interface IMyInterface with
+        member _.MyMethod() = ()
+
+let IMyInterfaceAttribute = 
+    Attribute.GetCustomAttribute(typeof<IMyInterface>, typeof<GuidAttribute>) :?> GuidAttribute
+
+printfn $"IMyInterface Attribute: {IMyInterfaceAttribute.Value}"
+
+// Use the string to create a guid.
+let myGuid1 = Guid IMyInterfaceAttribute.Value
+// Use a byte array to create a guid.
+let myGuid2 = Guid(myGuid1.ToByteArray())
+
+if myGuid1.Equals myGuid2 then
+    printfn "myGuid1 equals myGuid2"
+else
+    printfn "myGuid1 does not equal myGuid2"
+
+// Equality operator can also be used to determine if two guids have same value.
+if myGuid1 = myGuid2 then
+    printfn "myGuid1 == myGuid2"
+else
+    printfn "myGuid1 <> myGuid2"
+
+// The example displays the following output:
+//       IMyInterface Attribute: F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4
+//       myGuid1 equals myGuid2
+//       myGuid1 == myGuid2
+//</Snippet1>
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="Guids.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="parseex1.fs" />
+    <Compile Include="parseexactex1.fs" />
+    <Compile Include="tryparseex1.fs" />
+    <Compile Include="tryparseexactex1.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,29 @@
+module parseex1
+
+// <Snippet3>
+open System
+
+let originalGuid = Guid.NewGuid()
+// Create an array of string representations of the GUID.
+let stringGuids =
+    [| originalGuid.ToString "B"
+       originalGuid.ToString "D"
+       originalGuid.ToString "X" |]
+
+// Parse each string representation.
+for stringGuid in stringGuids do
+    try
+        let newGuid = Guid.Parse stringGuid
+        printfn $"Converted {stringGuid} to a Guid"
+    with
+    | :? ArgumentNullException ->
+        printfn "The string to be parsed is null."
+    | :? FormatException ->
+        printfn $"Bad format: {stringGuid}"
+
+// The example displays output similar to the following:
+//
+//    Converted {81a130d2-502f-4cf1-a376-63edeb000e9f} to a Guid
+//    Converted 81a130d2-502f-4cf1-a376-63edeb000e9f to a Guid
+//    Converted {0x81a130d2,0x502f,0x4cf1,{0xa3,0x76,0x63,0xed,0xeb,0x00,0x0e,0x9f}} to a Guid
+// </Snippet3>
@@ -0,0 +1,34 @@
+module parseexactex1
+
+// <Snippet4>
+open System
+
+// Define an array of all format specifiers.
+let formats =
+    [| "N"; "D"; "B"; "P"; "X" |]
+
+let guid = Guid.NewGuid()
+
+// Create an array of valid Guid string representations.
+let stringGuids = 
+    Array.map guid.ToString formats
+
+// Parse the strings in the array using the "B" format specifier.
+for stringGuid in stringGuids do
+    try
+        let newGuid = Guid.ParseExact(stringGuid, "B")
+        printfn $"Successfully parsed {stringGuid}"
+    with
+    | :? ArgumentNullException ->
+        printfn "The string to be parsed is null."
+    | :? FormatException ->
+        printfn $"Bad Format: {stringGuid}"
+
+// The example displays output similar to the following:
+//
+//    Bad Format: eb5c8c7d187a44e68afb81e854c39457
+//    Bad Format: eb5c8c7d-187a-44e6-8afb-81e854c39457
+//    Successfully parsed {eb5c8c7d-187a-44e6-8afb-81e854c39457}
+//    Bad Format: (eb5c8c7d-187a-44e6-8afb-81e854c39457)
+//    Bad Format: {0xeb5c8c7d,0x187a,0x44e6,{0x8a,0xfb,0x81,0xe8,0x54,0xc3,0x94,0x57}}
+// </Snippet4>
@@ -0,0 +1,27 @@
+module tryparseex1
+
+// <Snippet2>
+open System
+
+let originalGuid = Guid.NewGuid()
+
+// Create an array of string representations of the GUID.
+let stringGuids =
+    [| originalGuid.ToString "B"
+       originalGuid.ToString "D"
+       originalGuid.ToString "X" |]
+
+// Parse each string representation.
+for stringGuid in stringGuids do
+    match Guid.TryParse stringGuid with
+    | true, newGuid ->
+        printfn $"Converted {stringGuid} to a Guid"
+    | _ ->
+        printfn $"Unable to convert {stringGuid} to a Guid"
+
+// The example displays output similar to the following:
+//
+//    Converted {81a130d2-502f-4cf1-a376-63edeb000e9f} to a Guid
+//    Converted 81a130d2-502f-4cf1-a376-63edeb000e9f to a Guid
+//    Converted {0x81a130d2,0x502f,0x4cf1,{0xa3,0x76,0x63,0xed,0xeb,0x00,0x0e,0x9f}} to a Guid
+// </Snippet2>
@@ -0,0 +1,30 @@
+module tryparseexactex1
+
+// <Snippet5>
+open System
+
+// Define an array of all format specifiers.
+let formats = [| "N"; "D"; "B"; "P"; "X" |]
+
+let guid = Guid.NewGuid()
+
+// Create an array of valid Guid string representations.
+let stringGuids = 
+    Array.map guid.ToString formats
+
+// Parse the strings in the array using the "B" format specifier.
+for stringGuid in stringGuids do
+    match Guid.TryParseExact(stringGuid, "B") with
+    | true, newGuid ->
+        printfn $"Successfully parsed {stringGuid}"
+    | _ ->
+        printfn $"Unable to parse '{stringGuid}'"
+
+// The example displays output similar to the following:
+//
+//    Unable to parse 'c0fb150f6bf344df984a3a0611ae5e4a'
+//    Unable to parse 'c0fb150f-6bf3-44df-984a-3a0611ae5e4a'
+//    Successfully parsed {c0fb150f-6bf3-44df-984a-3a0611ae5e4a}
+//    Unable to parse '(c0fb150f-6bf3-44df-984a-3a0611ae5e4a)'
+//    Unable to parse '{0xc0fb150f,0x6bf3,0x44df,{0x98,0x4a,0x3a,0x06,0x11,0xae,0x5e,0x4a}}'
+// </Snippet5>