How to get key from SelectedItem of ComboBox?

c#, combobox, keyvaluepair

Solution

In cases like this, dictionaries are simply collections of key-value pairs, so each item on the `ComboBox` is a `KeyValuePair<YourKeyType, YourValueType>`. Cast `SelectedItem` to a `KeyValuePair<YourKeyType, YourValueType>` and then you can read the key.

// get ComboBox from sender
ComboBox comboBox = (ComboBox) sender;

// get selected KVP
KeyValuePair<YourKeyType, YourValueType> selectedEntry
    = (KeyValuePair<YourKeyType, YourValueType>) comboBox.SelectedItem;

// get selected Key
YourKeyType selectedKey = selectedEntry.Key;

Or, a simpler way is to use the `SelectedValue` property.

// get ComboBox from sender
ComboBox comboBox = (ComboBox) sender;

// get selected Key
YourKeyType selectedKey = (YourKeyType) comboBox.SelectedValue;

Problem

I am trying to get the key of `SelectedItem` of `ComboBox` but do not figure it out how to get code which I have done is, ``` void CboBoxSortingDatagridview(ComboBox sender) { foreach (var v in DictionaryCellValueNeeded) { if (!DictionaryGeneralUsers.ContainsKey(v.Key) && v.Value.RoleId == Convert.ToInt32(((ComboBox)sender).SelectedItem)) // here getting value {1,Admin} i want key value which is 1 but how? { DictionaryGeneralUsers.Add(v.Key, (GeneralUser)v.Value); } } dataGridViewMain.DataSource = DictionaryGeneralUsers.Values; } ``` I binded the combo box in this way, ``` cboRolesList.DataSource = new BindingSource(dictionaryRole, null); cboRolesList.DisplayMember = "Value"; cboRolesList.ValueMember = "Key"; ```

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