SortedDictionary item key position reordering

I need to be able to reorder a list of numbers based on a button click of a increased/decreased arrow button. So I have a list of items currently in a SortedDoctionary. When I print it out it looks like this:

key : value    
 1  :  1
 2  :  2
 3  :  25
 4  :  29
 5  :  31

When a user clicks the "UP" button I would like to change key[3] to key[2]. So just swap the position. The end results should give me an output like this:

key : value
 1  :  1
 2  :  25
 3  :  2
 4  :  29
 5  :  31

So I need to switch开发者_开发百科 the position up or down in the list. Any help would be greatly appreciated!

Assuming you have Dictionary<int, int> dict, try this:

private void Swap(int key)
{
    int swap = dict[key];
    dict[key] = dict[key + 1];
    dict[key + 1] = swap;
}

or

private void Swap(int key1, int key2)
{
    if (key1 != key2)
    {
        int swap = dict[key1];
        dict[key1] = dict[key2];
        dict[key2] = swap;
    }
}

int index1 = 2;
int index2 = 3;

var temp = myDict[index1];
myDict[index1] = myDict[index2];
myDict[index2] = temp;

It's the classical swap-through-a-temp-variable (to distinguish it from the swap-through-xor). Where was the problem?

As it is a sorted list, presumably you want the Key to stay the same, but swap the value?

var lower = 2;
var upper = 3;

var tmp = collection[lower];
collection[lower] = collection[upper];
collection[upper] = tmp;