Compiler Warning (Level 1) CS1957

Member 'name' overrides 'method'. There are multiple override candidates at run-time. It is implementation dependent which method will be called.

Method parameters that vary only by whether they are ref or out cannot be differentiated at run-time.

To avoid this warning

  1. Give one of the methods a different name or different number of parameters.

Example

The following code generates CS1957:

// cs1957.cs  
class Base<T, S>  
{  
    public virtual string Test(out T x) // CS1957  
    {  
        x = default(T);  
        return "Base.Test";  
    }  
    public virtual void Test(ref S x) { }  
}  

class Derived : Base<int, int>  
{  
    public override string Test(out int x)  
    {  
        x = 0;  
        return "Derived.Test";  
    }  

    static int Main()  
    {  
        int x;  
        if (new Derived().Test(out x) == "Derived.Test")  
            return 0;  
        return 1;  
    }  
}