C# - Selectively suppress custom Obsolete warnings

Use #pragma warning disable:

using System;

class Test
{
    [Obsolete("Message")]
    static void Foo(string x)
    {
    }

    static void Main(string[] args)
    {
#pragma warning disable 0618
        // This one is okay
        Foo("Good");
#pragma warning restore 0618

        // This call is bad
        Foo("Bad");
    }
}

Restore the warning afterwards so that you won't miss "bad" calls.

The intent is to disable the warning for obsolete usage, regardless of whether the construct is marked with [Obsolete] or [Obsolete("Message")]. So use both CS0612 and CS0618:

#pragma warning disable 612, 618 

...

#pragma warning restore 612, 618 

Here's how to get the warning/error number in the first place:

1. Rebuild your project.
2. Go to the Output window.
3. Look up the line of the warning/error you want to suppress.
   For example:
   C:\Users\Username\Documents\Visual Studio 2010\Projects\Projectname\Classname.cs(203,7): warning CS0162: Unreachable code detected
4. Copy the number part after "CS".
5. Then proceed as Jon Skeet says.

_{(Better always proceed as Jon Skeet says…)}