如何从ComboBox的SelectedItem获取密钥？

Question

我想获得的关键SelectedItem的ComboBox,但不弄清楚如何让我做的是代码,

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;
}  

我用这种方式绑定了组合框,

cboRolesList.DataSource = new BindingSource(dictionaryRole, null);  
cboRolesList.DisplayMember = "Value";  
cboRolesList.ValueMember = "Key";

Answer 1

在这种情况下,字典只是键值对的集合,因此每个项目ComboBox都是a KeyValuePair<YourKeyType, YourValueType>.转换SelectedItem为a KeyValuePair<YourKeyType, YourValueType>然后你可以读取密钥.

// 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;

或者,更简单的方法是使用该SelectedValue属性.

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

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