Need to Compare Two Generic Objects Using Greater Than or Less Than
c#, comparison
Solution
It sounds like you should just be able to cast `actualPropertyValue` to `IComparable`:
IComparable comparable = (IComparable) actualPropertyValue;
return comparable != null && comparable.CompareTo(Value) > 0;
Note that your use of the word "generic" is curious here. If you actually made it generic, you could write:
private bool IsRequired<T>(T actualPropertyValue) where T : IComparable
Then you wouldn't need the cast.
Problem
Synopsis: I have a need to take two generic C# objects, and if they are numerical, compare them using either less than or greater than comparisons. Problem: I can't figure out how to have my class implement IComparable as described in this post: Having to implement a generic less than and greater than operation. If that's not even the proper path to take, then I need to know that as well. Background: I have implemented the RequiredIf ValidationAttribute found at A more complex custom validator but needed the > and < options in addition to an equals comparison. Code (taken from A more complex custom validator, one-third down the page): ``` private bool IsRequired(object actualPropertyValue) { switch (Comparison) { case Comparison.IsLessThan: case Comparison.IsLessThanOrEqualTo: case Comparison.IsGreaterThan: case Comparison.IsGreaterThanOrEqualTo: if (!Value.IsNumber()) { throw new Exception("The selected comparison option is only applicable to numeric values"); } break; } switch (Comparison) { case Comparison.IsNotEqualTo: return actualPropertyValue == null || !actualPropertyValue.Equals(Value); case Comparison.IsEqualTo: return actualPropertyValue != null && actualPropertyValue.Equals(Value); case Comparison.IsGreaterThan: // THIS LINE FAILS BECAUSE actualPropertyValue DOESN'T IMPLEMENT IComparable return actualPropertyValue != null && (actualPropertyValue.CompareTo(Value) > 0); // The rest of the comparison cases go here... default: throw new Exception("Comparison value is not defined"); } } ``` Static Helper Extensions: ``` public static bool IsNumber(this object value) { if (value is sbyte) return true; if (value is byte) return true; if (value is short) return true; if (value is ushort) return true; if (value is int) return true; if (value is uint) return true; if (value is long) return true; if (value is ulong) return true; if (value is float) return true; if (value is double) return true; if (value is decimal) return true; return false; } ```