c# - 如何从 ComboBox 的 SelectedItem 中获取 key？

Question

我正在尝试获取 ComboBox 的 SelectedItem 的键，但不知道如何获取我已经完成的代码，

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;
}  

我是这样绑定(bind)组合框的，

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，所以 ComboBox 上的每一项是 KeyValuePair<YourKeyType, YourValueType> .投SelectedItem到 KeyValuePair<YourKeyType, YourValueType>然后你就可以读取 key 了。

// 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 SelectedValue属性(property)。

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

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