Add HttpClient to resolve deprecation of WebRequest

Example/FetcherTest.cs

@@ -7,6 +7,7 @@
 using System.Drawing;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 
@@ -19,34 +20,59 @@ public FetcherTest()
             InitializeComponent();
         }
 
-        private void btnFetch_Click(object sender, EventArgs e)
+        private bool _isFetching = false;
+        private CancellationTokenSource _cancellationTokenSource = null;
+
+        private async void btnFetch_Click(object sender, EventArgs e)
         {
+            if (_isFetching)
+            {
+                _cancellationTokenSource?.Cancel();
+                return;
+            }
+
+            _isFetching = true;
+            ((Button)sender).Text = "Cancel";
+
             try
             {
                 var uri = new Uri(txtUri.Text);
                 var minSize = (int)numMinSize.Value;
                 var maxSize = (int)numMaxSize.Value;
                 var perfectSize = (int)numPerfectSize.Value;
 
+                _cancellationTokenSource = new CancellationTokenSource();
+
                 picIcon.Size = new Size(16, 16);
                 picIcon.Image = null;
 
-                var image = new Fetcher().Fetch(uri, new FetchOptions
-                {
-                    MinimumSize = new IconSize(minSize, minSize),
-                    MaximumSize = new IconSize(maxSize, maxSize),
-                    PerfectSize = new IconSize(perfectSize, perfectSize)
-                });
+                var image = await new Fetcher().Fetch(
+                    uri,
+                    new FetchOptions
+                    {
+                        MinimumSize = new IconSize(minSize, minSize),
+                        MaximumSize = new IconSize(maxSize, maxSize),
+                        PerfectSize = new IconSize(perfectSize, perfectSize)
+                    },
+                    _cancellationTokenSource);
+
                 if (image != null)
                 {
                     picIcon.Size = new Size(image.Size.Width, image.Size.Height);
                     picIcon.Image = image.ToSKBitmap().ToBitmap();
                 }
             }
+            catch (TaskCanceledException) { }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message);
             }
+            finally
+            {
+                _cancellationTokenSource?.Dispose();
+                _isFetching = false;
+                ((Button)sender).Text = "Fetch";
+            }
         }
     }
 }

Example/ScannerTest.cs

@@ -5,6 +5,7 @@
 using System.Data;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 
@@ -27,26 +28,48 @@ private void lstResults_Resize(object sender, EventArgs e)
             _ExpandLocationColumn();
         }
 
-        private void btnScan_Click(object sender, EventArgs e)
+        private bool _isScanning = false;
+        private CancellationTokenSource _cancellationTokenSource = null;
+
+        private async void btnScan_Click(object sender, EventArgs e)
         {
             try
             {
+                if (_isScanning)
+                {
+                    _cancellationTokenSource?.Cancel();
+                    return;
+                }
+
+                _isScanning = true;
+                ((Button)sender).Text = "Cancel";
+
                 var uri = new Uri(txtUri.Text);
 
                 lstResults.Items.Clear();
 
-                foreach (var result in new Scanner().Scan(uri))
+                _cancellationTokenSource = new CancellationTokenSource();
+
+                foreach (var result in await new Scanner().Scan(uri, _cancellationTokenSource))
                 {
                     lstResults.Items.Add(new ListViewItem(new[]{
                         result.ExpectedSize.ToString(),
                         result.Location.ToString()
                     }));
                 }
             }
+            catch (TaskCanceledException) { }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message);
             }
+            finally
+            {
+                _cancellationTokenSource?.Dispose();
+                _isScanning = false;
+                ((Button)sender).Text = "Scan";
+                _cancellationTokenSource?.Dispose();
+            }
         }
 
         private void _ExpandLocationColumn()

FaviconFetcher.Tests/BrowserConfigXmlScannerTests.cs

@@ -29,7 +29,7 @@ public void Start_ValidXml_Parse()
                 </browserconfig>");
 
             var scanner = new BrowserconfigXmlScanner(source, uri);
-            scanner.Start();
+            scanner.Start().GetAwaiter();
 
             Assert.AreEqual(4, scanner.Results.Count);
         }
@@ -43,7 +43,7 @@ public void Start_InvalidXml_Skip()
                 <browserconfig>>");
 
             var scanner = new BrowserconfigXmlScanner(source, uri);
-            scanner.Start();
+            scanner.Start().GetAwaiter();
 
             Assert.AreEqual(0, scanner.Results.Count);
         }
@@ -68,7 +68,7 @@ public void Start_ContainsInvalidUri_Skip()
                 </browserconfig>");
 
             var scanner = new BrowserconfigXmlScanner(source, uri);
-            scanner.Start();
+            scanner.Start().GetAwaiter();
 
             Assert.AreEqual(3, scanner.Results.Count);
         }