Why do I get the error "Unsafe code may only appear if compiling with /unsafe"?

Question

Why do I get the following error?

Unsafe code may only appear if compiling with /unsafe"?

I work in C# and Visual Studio 2008 for programming on Windows CE.

Arise

See msdn.microsoft.com/en-us/library/ezb5hwx9%28VS.80%29.aspx and msdn.microsoft.com/en-us/library/t2yzs44b%28VS.80%29.aspx – Chrysalis

Possible duplicate of I can seem to get msbuild to build unsafe code blocks – Trinetta

Answer 1

To use unsafe code blocks, the project has to be compiled with the /unsafe switch on.

Open the properties for the project, go to the Build tab and check the Allow unsafe code checkbox.

Brannen

I must say, even though that does enable the build to compile, it still doesn't allow it to get published to the web :/ – Twain

@Nick: Yes, if you publish code to be compiled dynamically, then the project settings doesn't apply. See #16567697 – Brannen

Note that the settings might differ between Debug and Release compile. This just cost me 20 minutes of my life. – Kolivas

You may have to change the build configuration from Debug to Release for different type of builds – Walford

Answer 2

Here is a screenshot:

ََََََََ

Feck

Important: Also be aware that this screenshot is for "Configuration: Active (Debug)". You'll probably also need to change it for "Release", since that's most likely what you're publishing. – Austrasia

Answer 3

Can also add AllowUnsafeBlocks tag to PropertyGroup directly in .csproj file

<PropertyGroup>
    <TargetFrameworks>netcoreapp3.1; net472</TargetFrameworks>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
</PropertyGroup>

Bellboy

Answer 4

Probably because you're using unsafe code.

Are you doing something with pointers or unmanaged assemblies somewhere?

Riva

Answer 5

Search your code for unsafe blocks or statements. These are only valid is compiled with /unsafe.

Beaverboard

Answer 6

To use unsafe code blocks, open the properties for the project, go to the Build tab and check the Allow unsafe code checkbox, then compile and run.

class myclass
{
     public static void Main(string[] args)
     {
         unsafe
         {
             int iData = 10;
             int* pData = &iData;
             Console.WriteLine("Data is " + iData);
             Console.WriteLine("Address is " + (int)pData);
         }
     }
}

Output:

Data is 10
Address is 1831848

Dunedin

Answer 7

For everybody who uses Rider you have to select your project>Right Click>Properties>Configurations Then select Debug and Release and check "Allow unsafe code" for both.

Fleuron

Answer 8

I add this Line to Project file <AllowUnsafeBlocks>true</AllowUnsafeBlocks> it work for me.

Merrythought