C# 10: Disable Global Using

In C# 10, the global using directive is enabled by default. This means that any namespace that is declared in the global using directive is available to all source files in the project.

If you want to disable the global using directive, you can do so by adding the following line to the top of your project file:

<PropertyGroup>
  <LangVersion>preview</LangVersion>
</PropertyGroup>

This will disable the global using directive and you will need to explicitly import any namespaces that you want to use in your source files.

For example, if you want to use the System.Console namespace, you would need to add the following line to the top of your source file:

using System.Console;

Disabling the global using directive can be useful if you want to have more control over which namespaces are available to your source files. It can also help to improve the readability of your code by making it clear which namespaces are being used.

In C# 10, the new feature of global using directives has been introduced, which allows you to have a set of namespaces available throughout your project without the need to add a using directive to every file. However, if you want to disable this feature and see the used namespaces at a glance, you can follow these steps:

1. Open your project in Visual Studio or Visual Studio Code.
2. Go to the project file (.csproj) of your project.
3. Add the following property group to your .csproj file:

<PropertyGroup>
  <EnableGlobalUsingDirectives>false</EnableGlobalUsingDirectives>
</PropertyGroup>

4. Save the .csproj file and reload the project.

By adding the EnableGlobalUsingDirectives property and setting it to false, you are effectively disabling the global using directives feature in C# 10 for your project. Now, you will see the used namespaces at a glance and will not need to look up the documentation for the globally used namespaces.

<ImplicitUsings>disable</ImplicitUsings> has to be added to the PropertyGroup in the csproj-file. For example:

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <TargetFramework>net6.0</TargetFramework>
        <Nullable>enable</Nullable>
        <ImplicitUsings>disable</ImplicitUsings>
    </PropertyGroup>
</Project>

If you are using a beta version of .NET 6, you will have to use <DisableImplicitNamespaceImports>true</DisableImplicitNamespaceImports>.

<ImplicitUsings>disable</ImplicitUsings> has to be added to the PropertyGroup in the csproj-file. For example:

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <TargetFramework>net6.0</TargetFramework>
        <Nullable>enable</Nullable>
        <ImplicitUsings>disable</ImplicitUsings>
    </PropertyGroup>
</Project>

If you are using a beta version of .NET 6, you will have to use <DisableImplicitNamespaceImports>true</DisableImplicitNamespaceImports>.

Sure, here's how you can disable the new default global usings in C# 10:

1. Disable the default global using directive:

// Disable the global using directive in a namespace
using MyNamespace; // This will no longer be used

// Using the disabled global using directive
var data = MyNamespace.MyClass.MyMethod();

2. Use the using statement:

// Use the using statement to specify namespaces directly
using MyNamespace {
    using MyClass {
        // Use members from the MyNamespace.MyClass namespace
        var data = MyClass.MyMethod();
    }
}

3. Use reflection to access specific namespaces:

// Use reflection to access the globally scoped namespaces
var namespaces = new AssemblyInfo().GetExecutingAssembly().GetReferencedNamespaces().Where(ns => ns.Name.EndsWith("."));

// Loop through the namespaces and use reflection to access the types
foreach (var namespace in namespaces)
{
    var type = Type.GetType(namespace + ".MyClass");
    // Use type.GetMembers() to access members of the type
}

4. Use the where clause with `using directives:**

// Use the where clause to filter namespaces with specific criteria
using Namespace1 {
    using Namespace2.SubNamespace;
    // Use members from the filtered namespaces
}

By using these techniques, you can disable the default global usings and maintain a clean and maintainable codebase.

To disable global usings in C# 10:

1. Use a tool to identify the global usings:

• Use the dotnet list usings command to get a list of all the usings in your project.
• Look for lines that start with using <namespace>; where <namespace> is a global namespace.

2. Edit the .csproj file:

• Open the .csproj file in a text editor.
• Find the <RootNamespace> element.
• Beneath the <RootNamespace> element, you should see a section called UsingDirectives.
• Within the UsingDirectives section, look for lines that start with using <namespace>; and remove them.

3. Save the .csproj file:

• Save the changes to the .csproj file.

Example:

Before:

using System;
using System.Threading.Tasks;

After:

using System;

// No global usings

Additional tips:

• You can also disable global usings in the Directory.Build.props file. To do this, add the following line to the file:

<ImportContext.DisableDefaultUsings>true</ImportContext.DisableDefaultUsings>

• Once you have disabled global usings, you can use the using keyword to explicitly import namespaces where you need them.

Note: Disabling global usings is a best practice for maintaining code readability and avoiding unnecessary dependencies. However, it is not mandatory. You can choose to keep the global usings if you prefer.

To disable the default global usings in C# 10, you can add the following attribute to your project's .csproj file:

<TargetFramework>netcoreapp-3.1</TargetFramework>

This attribute sets the version of the .NET Core framework that your project should use.

Now when you build your project using this version of the .NET Core framework, the default global usings in C# 10 will be disabled automatically.

Currently, there isn't an option to disable global usings in C# 10 (or any version) directly. The .editorconfig file settings are for controlling the usage of certain rules for whitespace, indentation, and other such properties, but they do not affect the global using directives or their behavior within the code editor or build tools.

The issue you mentioned is related to the integration between ASP.NET Core's Kestrel server and Blazor WebAssembly services which includes a known bug that causes it to fail on startup if no usings are present in the file for System, Microsoft.AspNetCore.Components.Web or other necessary namespaces.

To prevent this issue in the future, consider including necessary using directives at the start of your source files as a best practice even though global using feature may not be implemented in all tools/editors out there:

using System;
using Microsoft.AspNetCore.Components.Web; 
// Add other using statements here that are necessary for your code

Remember to check the documentation of any libraries you plan on using, as they might have dependencies which should be included in these global usings too.

I'm unable to directly modify the C# compiler or the ASP.NET Core project settings for you. However, I can suggest some alternatives to achieve similar results:

1. Use the using statement with explicit namespaces only: Instead of relying on the global usings, you can explicitly use your preferred namespaces at the beginning of each file using the using keyword. This will give you better control over which namespaces are imported and make it easier to understand the code at a glance.

2. Use ReSharper or other IDEs: IDEs like JetBrains Rider, Visual Studio with Resharper extension, and other similar tools offer various options to manage and inspect your using declarations effectively. They allow you to view all used namespaces, enable/disable specific usings, or even suggest alternative imports based on the current context.

3. Use .editorconfig file: You can create a .editorconfig file in your project directory to specify a list of namespaces to be excluded from the global using directive. Although this does not completely disable all global usings, it at least gives you more control over which ones are included.

4. Update your documentation and code editor: Keeping your documentation updated and readily accessible is a good practice. You can use tools like Markdown or other formats to write comprehensive documentation for each of your projects. Also, consider using an integrated code editor, like JetBrains Rider or Visual Studio Code, which offer features that help you easily view and navigate through your used namespaces and project structure.

5. Monitor changes in the compiler settings: Keep an eye on the development community for any updates on this issue regarding C# 10 global usings, and adjust your workflow accordingly if a solution arises. You may also consider voicing your concerns on discussion forums or GitHub repositories to contribute to the conversation around the future of compiler settings.

These suggestions should help you manage your using declarations in a C# 10 project, allowing you to maintain better control over your codebase while minimizing the need to refer to documentation on which namespaces are used globally.

One way to disable the new default global usings in C# 10 is to create a custom namespace for any namespace that you want to include. For example, if you only want to include the "System" and "Networking" namespaces, you can use the following code to define those two custom namespace packages:

namespace System
{
    using System;
    using System.Diagnostics;
    using System.Threading;
}

namespace Networking
{
    using Microsoft.Net;
    // ... other network-specific features go here
}

You can then reference these custom namespace packages by appending them to the name of any namespace in your code, like this: using System.System. This way, you'll be able to see only the specific namespaces that you need at a glance instead of seeing all the global usings in C# 10. Hope it helps! Let me know if you have any questions or if there is anything else I can assist you with.

You can disable the new default global usings in C# 10 by setting the "CSharpGlobalUsing" option to "false" in your project file (csproj).

Here is an example of how you can do this:

<PropertyGroup>
 <CSharpGlobalUsing>false</CSharpGlobalUsing>
</PropertyGroup>

With this option set, the global usings will be disabled and the namespaces used in your code will not be automatically imported. Instead, you will need to explicitly import the namespaces that you use in your code.

It is worth noting that disabling global usings can make your code easier to read and understand because it highlights which namespaces are actually being used. However, some people may find this change to be too subtle and prefer the global usings to be explicitly stated. Ultimately, the decision of whether or not to disable global usings is up to you and your development team.

#pragma warning disable CS8019