あなたが見逃しているのは、DialogViewController での PerformFilter の呼び出しだけだと思います。
動作を示す簡単なサンプルを入力しました。あなたが観察した正確な動作を見たことはありません。検索フィールドを再入力する必要はありませんでした。参考までに、私は Monotouch 5.2.11 を使用しています。
using System;
using System.Linq;
using MonoTouch.UIKit;
using MonoTouch.Dialog;
using MonoTouch.Foundation;
namespace delete201204242A
{
[Register ("AppDelegate")]
public partial class AppDelegate : UIApplicationDelegate
{
UIWindow _window;
UINavigationController _nav;
MyDialogViewController _rootVC;
public override bool FinishedLaunching (UIApplication app, NSDictionary options)
{
_window = new UIWindow (UIScreen.MainScreen.Bounds);
RootElement _rootElement = new RootElement ("LINQ root element") {
new Section ("List") {
from x in new Expense [] { new Expense () {Name="one"}, new Expense () {Name="two"}, new Expense () {Name="three"} }
select (Element)new BindingContext (null, x, x.Name).Root
}
};
_rootVC = new MyDialogViewController (_rootElement);
_rootVC.EnableSearch = true;
_nav = new UINavigationController (_rootVC);
_window.RootViewController = _nav;
_window.MakeKeyAndVisible ();
return true;
}
public class MyDialogViewController : DialogViewController
{
public MyDialogViewController (RootElement root) : base (root) {}
public string SearchString { get; set; }
public override void ViewDidAppear (bool animated)
{
base.ViewDidAppear (animated);
if (!string.IsNullOrEmpty (SearchString))
this.PerformFilter (SearchString);
}
public override void OnSearchTextChanged (string text)
{
base.OnSearchTextChanged (text);
SearchString = text;
}
}
public class Expense
{
[Section("Expense Entry")]
[Entry("Enter expense name")]
public string Name;
[Section("Expense Details")]
[Caption("Description")]
[Entry]
public string Details;
}
}
}