首页banner优化

AIK.Views/MenuPages/Home/HomePage.xaml

@@ -68,18 +68,22 @@
 
                 <!-- 左箭头 -->
                 <Button Command="{Binding PreviousCommand}"
-                Visibility="{Binding IsFirst, Converter={StaticResource BoolToVisibilityConverter}}"
+                Visibility="{Binding IsFirst, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=inverse}"
                 Style="{StaticResource NavButtonStyle}"
                 HorizontalAlignment="Left" Margin="30,0,0,0">
-                    <TextBlock Text="&#xE76B;" FontFamily="Segoe MDL2 Assets" FontSize="24" Foreground="#2B579A"/>
+                    <Path Data="M15,3 L7,12 L15,21" Stroke="#2B579A" StrokeThickness="2.5"
+                          Fill="Transparent" Width="22" Height="24" Stretch="Uniform"
+                          StrokeLineJoin="Round" StrokeStartLineCap="Round" StrokeEndLineCap="Round"/>
                 </Button>
 
                 <!-- 右箭头 -->
                 <Button Command="{Binding NextCommand}"
-                Visibility="{Binding IsLast, Converter={StaticResource BoolToVisibilityConverter}}"
+                Visibility="{Binding IsLast, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=inverse}"
                 Style="{StaticResource NavButtonStyle}"
                 HorizontalAlignment="Right" Margin="0,0,30,0">
-                    <TextBlock Text="&#xE76C;" FontFamily="Segoe MDL2 Assets" FontSize="24" Foreground="#2B579A"/>
+                    <Path Data="M9,3 L17,12 L9,21" Stroke="#2B579A" StrokeThickness="2.5"
+                          Fill="Transparent" Width="22" Height="24" Stretch="Uniform"
+                          StrokeLineJoin="Round" StrokeStartLineCap="Round" StrokeEndLineCap="Round"/>
                 </Button>
 
                 <!-- 指示器圆点 -->

ViewModels/HomePage/HomePageViewModel.cs

@@ -143,6 +143,10 @@ namespace AIK.ViewModels.HomePage
                         Debug.WriteLine($"Loaded: {(loaded - start).TotalMilliseconds}ms");
                     }
                 }
+                if (Banners.Count > 0 && CurrentIndexPublic < 0)
+                {
+                    CurrentIndexPublic = 0;
+                }
             }
             catch (Exception ex)
             {
@@ -159,10 +163,18 @@ namespace AIK.ViewModels.HomePage
         }
 
         [RelayCommand]
-        private void Previous() => CurrentIndexPublic = (CurrentIndexPublic - 1 + Banners.Count) % Banners.Count;
+        private void Previous()
+        {
+            if (Banners.Count == 0) return;
+            CurrentIndexPublic = (CurrentIndexPublic - 1 + Banners.Count) % Banners.Count;
+        }
 
         [RelayCommand]
-        private void Next() => CurrentIndexPublic = (CurrentIndexPublic + 1) % Banners.Count;
+        private void Next()
+        {
+            if (Banners.Count == 0) return;
+            CurrentIndexPublic = (CurrentIndexPublic + 1) % Banners.Count;
+        }
 
         [RelayCommand]
         private void SelectBanner(int index) => CurrentIndexPublic = index;