If you have an object in a list of these objects, you can find the index of the list by:
int index = listOfObjects.IndexOf(testObject);
But that only goes if the testObject reference is in the listOfObjects. If the object is not in the list, but you want to find the index based on a property, do this:
List<myObject> listOfObjects = new List<myObject>();
listOfObjects.Add(new myObject() { Name = "obj 1" });
listOfObjects.Add(new myObject() { Name = "obj 2" });
myObject testObject = new myObject() { Name= "obj 1"};
int index = listOfObjects.Select((s, i) => new { S = s, Index = i }).Where(i => i.S.Name == testObject.Name).First().Index;
Of cause you have to be shure that the testObject is in the list or you will get a exception.
