Use Random.Shared property (#31453)

* Use Random.Shared

Use the new .NET 6 Random.Shared static property where possible.
See dotnet/runtime#50297.

* Revert WebApi-CSharp changes

For some reason I don't understand, this template doesn't see Random.Shared when compiled so this reverts the previous change for this template.

Author: martincostello

src/Components/Samples/BlazorServerApp/Data/WeatherForecastService.cs

@@ -13,12 +13,11 @@ public class WeatherForecastService
 
         public Task<WeatherForecast[]> GetForecastAsync(DateTime startDate)
         {
-            var rng = new Random();
             return Task.FromResult(Enumerable.Range(1, 5).Select(index => new WeatherForecast
             {
                 Date = startDate.AddDays(index),
-                TemperatureC = rng.Next(-20, 55),
-                Summary = Summaries[rng.Next(Summaries.Length)]
+                TemperatureC = Random.Shared.Next(-20, 55),
+                Summary = Summaries[Random.Shared.Next(Summaries.Length)]
             }).ToArray());
         }
     }

src/Components/WebAssembly/Samples/HostedBlazorWebassemblyApp/Server/Data/WeatherForecastService.cs

@@ -15,12 +15,11 @@ public class WeatherForecastService : IWeatherForecastService
 
         public Task<WeatherForecast[]> GetForecastAsync(DateTime startDate)
         {
-            var rng = new Random();
             return Task.FromResult(Enumerable.Range(1, 5).Select(index => new WeatherForecast
             {
                 Date = startDate.AddDays(index),
-                TemperatureC = rng.Next(-20, 55),
-                Summary = Summaries[rng.Next(Summaries.Length)]
+                TemperatureC = Random.Shared.Next(-20, 55),
+                Summary = Summaries[Random.Shared.Next(Summaries.Length)]
             }).ToArray());
         }
     }

src/Components/WebAssembly/testassets/Wasm.Authentication.Server/Controllers/WeatherForecastController.cs

@@ -28,12 +28,11 @@ public WeatherForecastController(ILogger<WeatherForecastController> logger)
         [HttpGet]
         public IEnumerable<WeatherForecast> Get()
         {
-            var rng = new Random();
             return Enumerable.Range(1, 5).Select(index => new WeatherForecast
             {
                 Date = DateTime.Now.AddDays(index),
-                TemperatureC = rng.Next(-20, 55),
-                Summary = Summaries[rng.Next(Summaries.Length)]
+                TemperatureC = Random.Shared.Next(-20, 55),
+                Summary = Summaries[Random.Shared.Next(Summaries.Length)]
             })
             .ToArray();
         }

src/Components/benchmarkapps/BlazingPizza.Server/Pages/Map.razor

@@ -10,16 +10,15 @@
 @functions {
     private int locX;
     private int locY;
-    private Random random = new Random();
     private Timer timer;
     private string locString;
 
     protected override void OnInitialized()
     {
         timer = new Timer(_ =>
         {
-            locX = random.Next(1000);
-            locY = random.Next(1000);
+            locX = Random.Shared.Next(1000);
+            locY = Random.Shared.Next(1000);
             locString = $"{locX},{locY}";
 
             InvokeAsync(() => StateHasChanged());

src/Components/benchmarkapps/Wasm.Performance/TestApp/Pages/TimerComponent.razor

@@ -7,7 +7,6 @@
 
 @code
 {
-    Random random = new Random();
     Timer timer;
     int red = 128;
     int green = 128;
@@ -22,9 +21,9 @@
     {
         InvokeAsync(() =>
         {
-            red = random.Next(0, 256);
-            green = random.Next(0, 256);
-            blue = random.Next(0, 256);
+            red = Random.Shared.Next(0, 256);
+            green = Random.Shared.Next(0, 256);
+            blue = Random.Shared.Next(0, 256);
             StateHasChanged();
             BenchmarkEvent.Send(JSRuntime, "Finished updating color");
         });

src/Components/test/testassets/BasicTestApp/ReorderingFocusComponent.razor

@@ -31,7 +31,6 @@
 </ul>
 
 @code {
-    Random rng = new Random();
     TodoItem[] todoItems = new[]
     {
         new TodoItem { Id = 1, Text = "First" },
@@ -43,7 +42,7 @@
 
     void Shuffle()
     {
-        todoItems = todoItems.OrderBy(x => rng.Next()).ToArray();
+        todoItems = todoItems.OrderBy(x => Random.Shared.Next()).ToArray();
     }
 
     class TodoItem

src/DataProtection/DataProtection/src/KeyManagement/KeyRingProvider.cs

@@ -259,7 +259,12 @@ private static TimeSpan GetRefreshPeriodWithJitter(TimeSpan refreshPeriod)
             // hit a single repository simultaneously. For instance, if the refresh period is 1 hour,
             // we'll return a value in the vicinity of 48 - 60 minutes. We use the Random class since
             // we don't need a secure PRNG for this.
-            return TimeSpan.FromTicks((long)(refreshPeriod.Ticks * (1.0d - (new Random().NextDouble() / 5))));
+#if NET6_0_OR_GREATER
+            var random = Random.Shared;
+#else
+            var random = new Random();
+#endif
+            return TimeSpan.FromTicks((long)(refreshPeriod.Ticks * (1.0d - (random.NextDouble() / 5))));
         }
 
         private static DateTimeOffset Min(DateTimeOffset a, DateTimeOffset b)

src/Http/Routing/test/UnitTests/RouteCollectionTest.cs

@@ -512,8 +512,7 @@ private static RouteCollection GetRouteCollectionWithNamedRoutes(IEnumerable<str
 
         private static RouteCollection GetNestedRouteCollection(string[] routeNames)
         {
-            var random = new Random();
-            int index = random.Next(0, routeNames.Length - 1);
+            int index = Random.Shared.Next(0, routeNames.Length - 1);
             var first = routeNames.Take(index).ToArray();
             var second = routeNames.Skip(index).ToArray();
 

src/Identity/Specification.Tests/src/UserManagerSpecificationTests.cs

@@ -305,9 +305,8 @@ public async Task CheckSetEmailValidatesUser()
             var manager = CreateManager();
             manager.Options.User.RequireUniqueEmail = true;
             manager.UserValidators.Add(new UserValidator<TUser>());
-            var random = new Random();
-            var email = "foo" + random.Next() + "@example.com";
-            var newEmail = "bar" + random.Next() + "@example.com";
+            var email = "foo" + Random.Shared.Next() + "@example.com";
+            var newEmail = "bar" + Random.Shared.Next() + "@example.com";
             var user = CreateTestUser(email: email);
             IdentityResultAssert.IsSuccess(await manager.CreateAsync(user));
             IdentityResultAssert.IsSuccess(await manager.SetEmailAsync(user, newEmail));

src/Middleware/HeaderPropagation/samples/HeaderPropagationSample/Startup.cs

@@ -111,11 +111,10 @@ private static StringValues GenerateBetaFeatureOptions()
 
             var threshold = 0.80; // 20% chance for each feature in beta.
 
-            var random = new Random();
             var values = new List<string>();
             for (var i = 0; i < features.Length; i++)
             {
-                if (random.NextDouble() > threshold)
+                if (Random.Shared.NextDouble() > threshold)
                 {
                     values.Add(features[i]);
                 }