创建给定C＃中的Type的任何数字/原始值类型的非零实例

Question

Lets say you have a Type called primitiveType with primitiveType.IsPrimitive == true , how can you most succintly (without using a third-party library) create an instance of this with a non-zero value (eg value = 1)?

That is, the function could look like:

public static object CreateNonZero(Type primitiveType)
{
    if (!primitiveType.IsPrimitive)
    { throw new ArgumentException("type must be primitive"); }

    // TODO
}

That is, it should work for all primitive value types eg bool, byte, sbyte, short, ushort, int, uint, long, ulong, float, double, IntPtr, UIntPtr, char etc.

Answer 1

Convert.ChangeType(1, primitiveType)

Note if you wanted to have the return type match your actual type rather than be object , it's relatively easy to do a generic version:

public static T CreateNonZero<T>()
{
    return (T)Convert.ChangeType(1, typeof(T));
}

If you want to handle IntPtr and UIntPtr , I don't know of any more elegant way than to check the type explicitly

public static object CreateNonZero(Type type)
{
    if(type == typeof(IntPtr))
        return new IntPtr(1);
    if(type == typeof(UIntPtr))
        return new UIntPtr(1);
    return Convert.ChangeType(1, type);
}