更新依赖和增强文件选择功能

在 `ExcelHelper.csproj` 中，将 `MiniExcel` 包版本从 `1.34.2` 升级到 `1.38.0`，并移除 `PolySharp` 包。
在 `ImportExcelPage.xaml` 中添加文件选择按钮，并设置相关属性。
在 `ImportExcelPage.xaml.cs` 中新增 `Button_Click` 方法以处理文件选择，及 `Grid_DragOver` 方法以支持拖拽文件功能。

src/ExcelHelper/ExcelHelper.csproj

@@ -59,14 +59,9 @@
     <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="9.3.0-preview.1.25114.11" />
     <PackageReference Include="Microsoft.Web.WebView2" Version="1.0.3116-prerelease" />
     <PackageReference Include="MiniExcel">
-      <Version>1.34.2</Version>
+      <Version>1.38.0</Version>
     </PackageReference>
     <PackageReference Include="Neo.Markdig.Xaml" Version="1.0.10" />
-    <PackageReference Include="PolySharp">
-      <Version>1.14.1</Version>
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
     <PackageReference Include="SQLite" Version="3.13.0" />
     <PackageReference Include="SqlSugarCore" Version="5.1.4.171-preview01" />
     <PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0" />

src/ExcelHelper/Views/Pages/ImportExcelPage.xaml

@@ -26,7 +26,12 @@
                     FontSize="20"
                     Foreground="White"
                     Text="拖拽Excel文件(.xls)到此处放开" />
-
+                <Button
+                    Margin="0,0,0,20"
+                    HorizontalAlignment="Center"
+                    VerticalAlignment="Bottom"
+                    Click="Button_Click"
+                    Content="选择文件" />
             </Grid>
         </DataTemplate>
         <DataTemplate x:Key="LoadingMask">
@@ -46,6 +51,7 @@
         AllowDrop="True"
         DragEnter="Grid_DragEnter"
         DragLeave="Grid_DragLeave"
+        DragOver="Grid_DragOver"
         Drop="Grid_Drop">
         <Grid.ColumnDefinitions>
             <ColumnDefinition Width="*" MinWidth="200" />

src/ExcelHelper/Views/Pages/ImportExcelPage.xaml.cs

@@ -74,5 +74,47 @@ public partial class ImportExcelPage : Page, IView, IRecipient<UpdateDataGridCol
         }
     }
 
-    
+    private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
+    {
+        // 选择一个Excel文件
+        // 创建打开文件对话框
+        var openFileDialog = new Microsoft.Win32.OpenFileDialog
+        {
+            Filter = "Excel文件|*.xlsx;*.xls",
+            Title = "选择Excel文件"
+        };
+
+        // 显示对话框
+        if (openFileDialog.ShowDialog() == true)
+        {
+            // 获取选择的文件路径
+            var filePath = openFileDialog.FileName;
+            // 调用ViewModel的方法处理文件
+            ViewModel.FileDrop(new string[] { filePath });
+            DropFileMask.Visibility = System.Windows.Visibility.Collapsed;
+        }
+
+    }
+
+
+    /// <summary>
+    /// 处理拖拽悬停事件
+    /// </summary>
+    private void Grid_DragOver(object sender, System.Windows.DragEventArgs e)
+    {
+        // 如果拖入的是文件
+        if (e.Data.GetDataPresent(System.Windows.DataFormats.FileDrop))
+        {
+            // 设置效果为复制，表示接受拖放
+            e.Effects = System.Windows.DragDropEffects.Copy;
+        }
+        else
+        {
+            // 不接受非文件拖放
+            e.Effects = System.Windows.DragDropEffects.None;
+        }
+
+        // 标记事件已处理，防止冒泡
+        e.Handled = true;
+    }
 }