1 files changed, 88 insertions, 0 deletions
diff --git a/Rx/NET/Samples/HOL/CS/Excercise9/Step04/Program.cs b/Rx/NET/Samples/HOL/CS/Excercise9/Step04/Program.cs
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index 0000000..e9cb8f6
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+++ b/Rx/NET/Samples/HOL/CS/Excercise9/Step04/Program.cs
@@ -0,0 +1,88 @@
+using System;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Windows.Forms;
+using System.Reactive.Disposables;
+using Excercise9.DictionarySuggestService;
+
+namespace Excercise9
+{
+    class Program
+    {
+        static void Main()
+        {
+            var txt = new TextBox();
+            var lst = new ListBox { Top = txt.Height + 10 };
+
+            var frm = new Form()
+            {
+                Controls = { txt, lst }
+            };
+
+#if PRODUCTION
+            // Turn the user input into a tamed sequence of strings.
+            var textChanged = from evt in Observable.FromEventPattern(txt, "TextChanged")
+                              select ((TextBox)evt.Sender).Text;
+                       
+            var input = textChanged
+                        .Throttle(TimeSpan.FromSeconds(1))
+                        .DistinctUntilChanged();
+#else
+            const string INPUT = "reactive";
+
+            var rand = new Random();
+
+            var input = Observable.Generate(
+                3,
+                len => len <= INPUT.Length,
+                len => len + 1,
+                len => INPUT.Substring(0, len),
+                _ => TimeSpan.FromMilliseconds(rand.Next(200, 1200))
+            )
+            .ObserveOn(txt)
+            .Do(term => txt.Text = term)
+            .Throttle(TimeSpan.FromSeconds(1));
+#endif
+
+            // Bridge with the web service's MatchInDict method.
+            var svc = new DictServiceSoapClient("DictServiceSoap");
+            var matchInDict = Observable.FromAsyncPattern<string, string, string, DictionaryWord[]>
+                (svc.BeginMatchInDict, svc.EndMatchInDict);
+
+#if PRODUCTION
+            Func<string, IObservable<DictionaryWord[]>> matchInWordNetByPrefix =
+                term => matchInDict("wn", term, "prefix");
+#else
+            Func<string, IObservable<DictionaryWord[]>> matchInWordNetByPrefix =
+                term => Observable.Return
+                (
+                    (from i in Enumerable.Range(0, rand.Next(0, 50))
+                     select new DictionaryWord { Word = term + i })
+                     .ToArray()
+                ).Delay(TimeSpan.FromSeconds(rand.Next(1, 10)));
+#endif
+
+            // The grand composition connecting the user input with the web service.
+            var res = (from term in input
+                      select matchInWordNetByPrefix(term))
+                      .Switch();
+
+            // Synchronize with the UI thread and populate the ListBox or signal an error.
+            using (res.ObserveOn(lst).Subscribe(
+                words =>
+                {
+                    lst.Items.Clear();
+                    lst.Items.AddRange((from word in words select word.Word).ToArray());
+                },
+                ex =>
+                {
+                    MessageBox.Show(
+                        "An error occurred: " + ex.Message, frm.Text, MessageBoxButtons.OK, MessageBoxIcon.Error
+                    );
+                }))
+            {
+                Application.Run(frm);
+            } // Proper disposal happens upon exiting the application.
+        }
+    }
+}