#error (C#)

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C# Language Reference

#error (C# Reference)

#error lets you generate an error from a specific location in your code. For example:

#error Deprecated code in this method.

Remarks

A common use of #error is in a conditional directive.

It is also possible to generate a user-defined warning with #warning (C# Reference).

Example

// preprocessor_error.cs
// CS1029 expected
#define DEBUG
class MainClass 
{
    static void Main() 
    {
#if DEBUG
#error DEBUG is defined
#endif
    }
}

Community Content

EddyHo88

Same error from my C# - Unsafe code may only appear if compiling with /unsafe - eddyho-88@hotmail.c

class Test
{
    public int num;
    public Test(int i) { num = i; }
}

class FixedCode
{
    class Program
    {
        unsafe static void Main(string[] args)
        {
            Test o = new Test(19);
            fixed (int* p = &o.num)
            {
                Console.WriteLine("Initial value of o.num is " + *p);
                *p = 10;
                Console.WriteLine("New value of o.num is " + *p);
            }
        }
    }
}
Error   1   Unsafe code may only appear if compiling with /unsafe   C:\Documents and Settings\Eddy Ho\My Documents\Visual Studio 2010\Projects\608-FixedCode\608-FixedCode\Program.cs   13   28   608-FixedCode

class UnsafeCode
{
      unsafe static void Main()
      {
        int count = 99;
        int* p;
        p = &count;
        Console.WriteLine("Initial value of count is " + *p);
        *p = 10;
        Console.WriteLine("New value of count is " + *p);
      }
}
Error   1   Unsafe code may only appear if compiling with /unsafe   C:\Documents and Settings\Eddy Ho\My Documents\Visual Studio 2010\Projects\608-UnsafeCode\608-UnsafeCode-Errors\Program.cs   5   26   608-UnsafeCode

class PtrArithDemo
{
    unsafe static void Main()
    //static void Main(string[] args)
    {
        int x;
        int i;
        double d;

        int* ip = &i;
        double* fp = &d;

        Console.WriteLine("int   double\n");
        for (x = 0; x < 10; x++)
        {
            Console.WriteLine((uint)(ip) + " " + (uint)(fp));
            ip++;
            fp++;
        }

    }
}
Error   1   Unsafe code may only appear if compiling with /unsafe   C:\Documents and Settings\Eddy Ho\My Documents\Visual Studio 2010\Projects\610-PtrArithDemo\610-PtrArithDemo\Program.cs   5   24   610-PtrArithDemo

#error (C#)

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