Wizard: fixed bug when trying to navigate to the previous page (first page) from the second WizardPage in the Items collection.

ExtendedWPFToolkitSolution/Src/Samples/Modules/Samples.Modules.Wizard/Views/HomeView.xaml

@@ -5,6 +5,20 @@
              xmlns:extToolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit/extended"
                       Title="Wizard">
     <Grid>
-        <TextBlock Text="Wizard View" />
+        <extToolkit:Wizard FinishButtonClosesWindow="True">
+            <extToolkit:WizardPage x:Name="IntroPage" 
+                                   Title="Welcome to my Wizard"
+                                   Description="This Wizard will walk you though how to do something." />
+            <extToolkit:WizardPage x:Name="Page1" PageType="Interior"
+                                   Title="Page 1"
+                                   Description="This is the first page in the process."/>
+            <extToolkit:WizardPage x:Name="Page2" PageType="Interior"
+                                   Title="Page 2"
+                                   Description="This is the second page in the process"/>
+            <extToolkit:WizardPage x:Name="LastPage" PageType="Interior"
+                                   Title="Last Page"
+                                   Description="This is the last page in the process"
+                                   CanFinish="True"/>
+        </extToolkit:Wizard>
     </Grid>
 </infControls:DemoView>

ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/Wizard/Implementation/Wizard.cs

@@ -307,7 +307,7 @@ namespace Microsoft.Windows.Controls
                     //no previous page defined so use index
                     var currentIndex = Items.IndexOf(CurrentPage);
                     var previousPageIndex = currentIndex - 1;
-                    if (previousPageIndex > 0 && previousPageIndex < Items.Count)
+                    if (previousPageIndex >= 0 && previousPageIndex < Items.Count)
                         previousPage = Items[previousPageIndex] as WizardPage;
                 }
             }
@@ -416,7 +416,7 @@ namespace Microsoft.Windows.Controls
                 //lets use an index to find the next page
                 var currentIndex = Items.IndexOf(CurrentPage);
                 var previousPageIndex = currentIndex - 1;
-                if (previousPageIndex > 0 && previousPageIndex < Items.Count)
+                if (previousPageIndex >= 0 && previousPageIndex < Items.Count)
                     exists = true;
             }