fix: add ManagedFileChooserOverwritePrompt styles.

demo/Semi.Avalonia.Demo/Pages/ManagedFileChooserDemo.axaml

@@ -13,8 +13,8 @@
                 <Setter Property="HorizontalAlignment" Value="Stretch" />
             </Style>
         </StackPanel.Styles>
-        <Button Name="openFileDialog">Open File</Button>
+        <Button Name="OpenFileButton" Content="Open File" />
-        <Button Name="selectFolderDialog">Select Folder</Button>
+        <Button Name="SelectFolderButton" Content="Select Folder" />
-        <Button Name="saveFileDialog">Save File</Button>
+        <Button Name="SaveFileButton" Content="Save File" />
     </StackPanel>
 </UserControl>

demo/Semi.Avalonia.Demo/Pages/ManagedFileChooserDemo.axaml.cs

@@ -1,10 +1,6 @@
-using System;
 using System.Collections.Generic;
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Dialogs;
 using Avalonia.Interactivity;
-using Avalonia.Markup.Xaml;
 using Avalonia.Platform.Storage;
 
 namespace Semi.Avalonia.Demo.Pages;
@@ -14,14 +10,14 @@ public partial class ManagedFileChooserDemo : UserControl
     public ManagedFileChooserDemo()
     {
         InitializeComponent();
-        openFileDialog.Click += OpenFileDialog;
+        OpenFileButton.Click += OpenFileDialog;
-        selectFolderDialog.Click += SelectFolderDialog;
+        SelectFolderButton.Click += SelectFolderDialog;
-        saveFileDialog.Click += SaveFileDialog;
+        SaveFileButton.Click += SaveFileDialog;
     }
 
-    private async void OpenFileDialog(object sender, RoutedEventArgs args)
+    private async void OpenFileDialog(object? sender, RoutedEventArgs args)
     {
-        IStorageProvider? sp = GetStorageProvider();
+        var sp = GetStorageProvider();
         if (sp is null) return;
         var result = await sp.OpenFilePickerAsync(new FilePickerOpenOptions()
         {
@@ -30,9 +26,10 @@ public partial class ManagedFileChooserDemo : UserControl
             AllowMultiple = true,
         });
     }
-    private async void SelectFolderDialog(object sender, RoutedEventArgs args)
+
+    private async void SelectFolderDialog(object? sender, RoutedEventArgs args)
     {
-        IStorageProvider? sp = GetStorageProvider();
+        var sp = GetStorageProvider();
         if (sp is null) return;
         var result = await sp.OpenFolderPickerAsync(new FolderPickerOpenOptions()
         {
@@ -40,16 +37,17 @@ public partial class ManagedFileChooserDemo : UserControl
             AllowMultiple = true,
         });
     }
-    private async void SaveFileDialog(object sender, RoutedEventArgs args)
+
+    private async void SaveFileDialog(object? sender, RoutedEventArgs args)
     {
-        IStorageProvider? sp = GetStorageProvider();
+        var sp = GetStorageProvider();
         if (sp is null) return;
         var result = await sp.SaveFilePickerAsync(new FilePickerSaveOptions()
         {
-            Title = "Open File",
+            Title = "Save File",
         });
     }
-    
+
     private IStorageProvider? GetStorageProvider()
     {
         var topLevel = TopLevel.GetTopLevel(this);
@@ -58,10 +56,10 @@ public partial class ManagedFileChooserDemo : UserControl
 
     List<FilePickerFileType>? GetFileTypes()
     {
-        return new List<FilePickerFileType>
+        return
-        {
+        [
             FilePickerFileTypes.All,
             FilePickerFileTypes.TextPlain
-        };
+        ];
     }
 }

src/Semi.Avalonia/Controls/ManagedFileChooser.axaml

@@ -4,6 +4,7 @@
     xmlns:converters="using:Semi.Avalonia.Converters"
     xmlns:dialogs="clr-namespace:Avalonia.Dialogs;assembly=Avalonia.Dialogs"
     xmlns:internal="clr-namespace:Avalonia.Dialogs.Internal;assembly=Avalonia.Dialogs"
+    xmlns:cvt="using:Avalonia.Controls.Converters"
     x:CompileBindings="True">
     <!--  Add Resources Here  -->
     <Design.PreviewWith>
@@ -194,4 +195,46 @@
             </ControlTemplate>
         </Setter>
     </ControlTheme>
+
+    <ControlTheme x:Key="{x:Type dialogs:ManagedFileChooserOverwritePrompt}"
+                  TargetType="dialogs:ManagedFileChooserOverwritePrompt">
+        <Setter Property="MaxWidth" Value="400" />
+        <Setter Property="Padding" Value="10"/>
+        <Setter Property="Template">
+            <ControlTemplate>
+                <Border Background="{TemplateBinding Background}"
+                        BorderBrush="{TemplateBinding BorderBrush}"
+                        BorderThickness="{TemplateBinding BorderThickness}"
+                        CornerRadius="{TemplateBinding CornerRadius}"
+                        Padding="{TemplateBinding Padding}">
+                    <StackPanel Spacing="10">
+                        <TextBlock TextWrapping="Wrap">
+                            <TextBlock.Text>
+                                <MultiBinding>
+                                    <MultiBinding.Converter>
+                                        <cvt:StringFormatConverter />
+                                    </MultiBinding.Converter>
+                                    <DynamicResource ResourceKey="STRING_CHOOSER_PROMPT_FILE_ALREADY_EXISTS" />
+                                    <TemplateBinding Property="FileName" />
+                                </MultiBinding>
+                            </TextBlock.Text>
+                        </TextBlock>
+                        <StackPanel HorizontalAlignment="Right"
+                                    Spacing="10"
+                                    Orientation="Horizontal">
+                            <Button Theme="{StaticResource SolidButton}"
+                                    Content="{DynamicResource STRING_CHOOSER_DIALOG_OK}"
+                                    HorizontalContentAlignment="Center"
+                                    IsDefault="True"
+                                    Command="{Binding Confirm, RelativeSource={RelativeSource TemplatedParent}}" />
+                            <Button Content="{DynamicResource STRING_CHOOSER_DIALOG_CANCEL}"
+                                    IsCancel="True"
+                                    HorizontalContentAlignment="Center"
+                                    Command="{Binding Cancel, RelativeSource={RelativeSource TemplatedParent}}" />
+                        </StackPanel>
+                    </StackPanel>
+                </Border>
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
 </ResourceDictionary>

src/Semi.Avalonia/Locale/en-us.axaml

@@ -21,4 +21,5 @@
     <x:String x:Key="STRING_CHOOSER_DATEMODIFIED_COLUMN">Date Modified</x:String>
     <x:String x:Key="STRING_CHOOSER_TYPE_COLUMN">Type</x:String>
     <x:String x:Key="STRING_CHOOSER_SIZE_COLUMN">Size</x:String>
+    <x:String x:Key="STRING_CHOOSER_PROMPT_FILE_ALREADY_EXISTS">{0} already exists. Do you want to replace it?</x:String>
 </ResourceDictionary>

src/Semi.Avalonia/Locale/ja-jp.axaml

@@ -21,4 +21,5 @@
     <x:String x:Key="STRING_CHOOSER_DATEMODIFIED_COLUMN">更新日時</x:String>
     <x:String x:Key="STRING_CHOOSER_TYPE_COLUMN">種類</x:String>
     <x:String x:Key="STRING_CHOOSER_SIZE_COLUMN">サイズ</x:String>
+    <x:String x:Key="STRING_CHOOSER_PROMPT_FILE_ALREADY_EXISTS">{0} はすでに存在します。置き換えますか？</x:String>
 </ResourceDictionary>

src/Semi.Avalonia/Locale/ru-ru.axaml

@@ -21,4 +21,5 @@
     <x:String x:Key="STRING_CHOOSER_DATEMODIFIED_COLUMN">Дата изменения</x:String>
     <x:String x:Key="STRING_CHOOSER_TYPE_COLUMN">Тип</x:String>
     <x:String x:Key="STRING_CHOOSER_SIZE_COLUMN">Размер</x:String>
+    <x:String x:Key="STRING_CHOOSER_PROMPT_FILE_ALREADY_EXISTS">{0} уже существует. Вы хотите заменить его?</x:String>
 </ResourceDictionary>

src/Semi.Avalonia/Locale/zh-cn.axaml

@@ -21,4 +21,5 @@
     <x:String x:Key="STRING_CHOOSER_DATEMODIFIED_COLUMN">修改日期</x:String>
     <x:String x:Key="STRING_CHOOSER_TYPE_COLUMN">类型</x:String>
     <x:String x:Key="STRING_CHOOSER_SIZE_COLUMN">大小</x:String>
+    <x:String x:Key="STRING_CHOOSER_PROMPT_FILE_ALREADY_EXISTS">{0} 已经存在。您要替换它吗？</x:String>
 </ResourceDictionary>