Question

When iam adding a DatagridviewRow to a Dictionary and Delete the DatagridviewRow also the Datagridviewrow in Dictionary changes. But i dont want the Dictionary to change

        Dictionary<int, CustomDataGridViewRow> _cache = new Dictionary<int, CustomDataGridViewRow>();

        public void add(int index, CustomDataGridViewRow row)
        {
            _cache.Add(index, row);
        }


        this.Rows.RemoveAt(1);

I tried a to clone the row, but i dont make a copy of the row, it makes a new row. look at this:

Answer 1

Then you need to clone the object before you add the dictionary entry.

A dictionary doesn’t contain objects – it contains references. The dictionary itself isn’t changing – it just contains a reference to the object which has changed.

If your object supports cloning, you can just use:

public void Add(int index, CustomDataGridViewRow row)
{
    _cache.Add(index, (CustomDataGridViewRow) row.Clone());
}

You may want to see the docs for DataGridViewRow.Clone for more details though…

Either way, it’s very important that you understand how reference types work in C#, otherwise you’ll keep bumping into this time and again.