can anyone tell me how I can search a hash table for a specific key and put off the corresponding value in a variable (e.g. Both key and value are from the class point)
I add the values as followed:
Hashtable Hash = new Hashtable(); Hash.Add(new Point(Po.X - 1, Po.Y), new Point(Po.X, Po.Y)); You can use the following:
Point value; if (Hash.ContainsKey(YourKey)) { value = (Point)Hash[YourKey]; } Instead of HashTable you should look at generic Dictionary<T,T>. (if you are using .Net framework 2.0 or higher)
But if you want to get the key from current non generic HashTable you can do:
var KeyToSearch = new Point(10 - 1, 20); if (Hash.ContainsKey(KeyToSearch)) { var value = Hash[KeyToSearch]; } But remember, value is of type object, and you have to use explicit cast to get Point object back like:
Point value = (Point) Hash[KeyToSearch] ; If you were to use Dictionary<Point,Point>, then you can achieve the same thing without casting.
One more thing to add, Point here is considered a struct from System.Drawing, If it is a class then ContainsKey and accessing based on Key would compare the reference and not the actual values. If your Point is a class (a reference type) then you have to override GetHashCode and Equals You may see this answer for more details.
