将 UIRefreshControl 添加到 TableView

假设：

TableView - 对 TableView 的引用

DataSource - 是一个继承 UITableViewSource 的类

DataSource.Objects - 是一个公共 List <object>（），可供 UIViewController 访问

private UIRefreshControl refreshControl;

public override void ViewDidLoad()
{
    base.ViewDidLoad();

    // Set the DataSource for the TableView
    TableView.Source = dataSource = new DataSource(this);

    // Create the UIRefreshControl
    refreshControl = new UIRefreshControl();

    // Handle the pullDownToRefresh event
    refreshControl.ValueChanged += refreshTable;

    // Add the UIRefreshControl to the TableView
    TableView.AddSubview(refreshControl);
}

private void refreshTable(object sender, EventArgs e)
{
    fetchData();
    refreshControl.EndRefreshing();
    TableView.ReloadData();
}

private void fetchData()
{
    var objects = new List<object>();
    // fetch data and store in objects.
    dataSource.Objects = objects;
}