C#

DateTime[] dt...;
Array.Sort(dt);

public class DTComparer : IComparer {
    public int Compare(object odt1, object odt2) {
        DateTime dt1=(DateTime)odt1;
        DateTime dt2=(DateTime)odt2;
        long diff=dt1.Ticks-dt2.Ticks;
        if (diff<0) return -1;
        if (diff>0) return 1;
        return 0;
    }
}
public void demo() {
    DateTime[] dt=new DateTime[]{
        DateTime.Now.AddDays(1),
        DateTime.Now.AddMinutes(1),
        DateTime.Now.AddHours(1)
    };
    log(dt);
    Array.Sort(dt, new DTComparer());
    log(dt);
}

public void log(DateTime[] dta) {
    log("DateTime[]:");
    foreach (DateTime dt in dta) log("    "+dt.ToString());
}

MBursill wrote:

BindingList<iimage> = images; // casting error
Why am I getting a casting error? If I understand the rules of polymorphisms correctly, so long as my Image class implements IImage, I can store any Image as an IImage without needing to explicitly cast.

MBursill wrote:

BindingList images = new BindingList();

BindingList<IImage> images = new BindingList<IImage>();