How to make use of cell reuse in UITableViewSource in Xamarin?

问题

I have UITableViewSource class which is used for the UISearchDisplayController. In my main table view I have a custom cell which works fine. Now I want to use the custom cell also for the table view of the search results. But I only manage it to display the default style with

public class SearchSource : UITableViewSource
{
    static NSString cellIdentifier = new NSString("CustomCell");

    public override UITableViewCell GetCell (UITableView tableView, NSIndexPath indexPath)
    {
        UITableViewCell cell = tableView.DequeueReusableCell (cellIdentifier);

        if (cell == null)
            cell = new UITableViewCell (UITableViewCellStyle.Default, cellIdentifier);

        cell.TextLabel.Text = myList [indexPath.Row].Name;
        return cell;
    }

But here I only have the standard cell and I want my custom cell. The custom cell on the main table view uses the following code:

public partial class TestViewController : UITableViewController
{
    static NSString cellIdentifier = new NSString("CustomCell");

    public TestViewController (IntPtr handle) : base (handle)
    {
        TableView.RegisterClassForCellReuse (typeof(CustomCell), cellIdentifier);
    }

    public class TableSource : UITableViewSource {

        public override UITableViewCell GetCell (UITableView tableView, NSIndexPath indexPath){
            CustomCell cell = (CustomCell)tableView.DequeueReusableCell (cellIdentifier);
            cell.UpdateCell(...);
    }
}

Here is the constructor of the CustomCell:

public CustomCell (IntPtr handle) : base(handle)

This is how I create the UISearchDisplayController:

// create search controller
searchBar = new UISearchBar (new RectangleF (0, 0, View.Frame.Width, 50)) {
    Placeholder = "Enter a search query"
};
searchController = new UISearchDisplayController (searchBar, this);
searchController.Delegate = new SearchDelegate (tableItems);
searchController.SearchResultsSource = new SearchSource (searchController);
this.TableView.TableHeaderView = searchBar;

But everything I try leads to a crash of the app (no reference, cannot dequeue, ...) or there is a constructor mismatch.

How can I use my custom cell for the table view generated by the UISearchDisplayController?

回答1:

Switching to the new cell reuse pattern since iOS 6 I adapted my SearchSource to

CustomPatientCell cell = (CustomCell)tableView.DequeueReusableCell (cellIdentifier);

and I added the following to my TestViewController:

searchController.SearchResultsTableView.RegisterClassForCellReuse(typeof(CustomCell), cellIdentifier);

I only had to add some methods like GetHeightForRow to my SearchSource to get this thing to work.

Now I have two similar implementations of TableSource and SearchSource - perhaps it is possible to summarize both? I saw from other implementations that methods like numberOfRowsInSection query which table view is currently active. How could I summarize that also?

来源：https://stackoverflow.com/questions/25306895/how-to-make-use-of-cell-reuse-in-uitableviewsource-in-xamarin