Disabling OBSOLETE error in C#

Question

I am using the Microsoft TFS API and one of the properties on one of the interfaces has been marked as Obsolete and it instructs me to use a different property. Unfortunately the property the API wants me to use is used by TFS2010 and not TFS2008.

I have tried doing this:

#pragma warning disable 0612, 0618
            request.CommandLineArguments = arguments;
#pragma warning restore 0612, 0618

But I still get the error that CommandLineArguments is obsolete. Is there anyway to suppress this?

EDIT

Unfortunately this is not showing up as a 'Warning as Error', in fact Treat Warning's As Error's is turned off in my project. Here is a screen cap of the offending code as well as the error list

EDIT 2:

After using ILSpy the CommandLineArguments property looks like this in the TFS2010 API:

    [Obsolete("This property has been deprecated. Please remove all references. To pass command line arguments to MSBuild.exe, set the ProcessParameters property.", true)]
    string CommandLineArguments
    {
        get;
        set;
    }

Unfortunately I don't think there is a way to tell the compiler to ignore the error that the Obsolete attribute is causing.

EDIT 3 As @Peter Ritchie points out this value could be set via reflection. As I thought through this problem though my guess is that if Microsoft set the property to throw an exception even if you did set it via reflection I doubt that the value would be referenced anywhere.

Answer 1

Visual Studio 2015

Build failing due to [Obsolete]?

This would only occur if "Treat Warnings As Errors" is enabled, and there is a method with the [Obsolete] attribute.

Method 1: Downgrade error to warning

Add <WarningsNotAsErrors>612,618</WarningsNotAsErrors> in the .csproj file (repeat for all sections):

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
    <WarningLevel>4</WarningLevel>
    <WarningsNotAsErrors>612,618</WarningsNotAsErrors>
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>bin\Debug\</OutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
</PropertyGroup>

If dealing with many .csproj files, see Appendix A: Notepad++ for search and replace.

Method 2: Ignore error in file

Note: This method is not recommended, because it hides the warnings for methods marked [Obsolete]. We still want to see a list of all calls to obsolete methods so we can upgrade them.

Use #pragma warning disable 612,618

Method 3: Ignore error in project

Note: This method is not recommended, because it hides the warnings for methods marked [Obsolete]. We still want to see a list of all calls to obsolete methods so we can upgrade them.

Edit the project (repeat for all sections):

Method 4: Ignore error in project

Note: This method is not recommended, because it hides the warnings for methods marked [Obsolete]. We still want to see a list of all calls to obsolete methods so we can upgrade them.

Manually edit your .csproj to disable warnings for specific errors. Add the tag <NoWarn>612,618</NoWarn> (repeat for all sections):

<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
    <NoWarn>612,618</NoWarn>
    <DebugSymbols>true</DebugSymbols>
    <OutputPath>bin\x64\Debug\</OutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
    <DebugType>full</DebugType>
    <PlatformTarget>x64</PlatformTarget>
    <ErrorReport>prompt</ErrorReport>        
</PropertyGroup>

---

Appendix A: Notepad++ for search and replace

Have a lot of files? No problem!

Open all .csproj files in NotePad++, then:

• Find: <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
• Replace: <TreatWarningsAsErrors>true</TreatWarningsAsErrors>\n\t<WarningsNotAsErrors>612,618</WarningsNotAsErrors>

Answer 2

Following works for me:

#pragma warning disable 612,618
            request.CommandLineArguments = arguments;
#pragma warning restore 612,618

notice no leading 0 in the numbers

EDIT: Okay, your assembly has the "true" argument in the ObsoleteAttribute constructor. This means you can't use the property and not get an error.

If you can't re-write your code to avoid using this property, you'll have to invoke the property setter via reflection, for example:

request.GetType().GetProperty("Number").SetValue(request, arguments, null);

and getting is similar:

(string)request.GetType().GetProperty("CommandLineArguments").GetValue(request, null);

Answer 3

Just in case anyone else stumbles on this.

If you mark the method in which you set the property as Obsolete and DONT mark it as true the compiler will ignore the interior error throwing your higher level warning instead which you can ignore.

IE

[Obsolete("Cause it aint",false)]
public void Foo(object arguments)
{
     request.CommandLineArguments = arguments;
}