[chore:] changed string to Uri for filePaths

MainWindow.axaml.cs

@@ -1,18 +1,21 @@
 using System;
 using Avalonia.Controls;
 using Avalonia.Interactivity;
+using Avalonia.Platform.Storage;
 
 namespace Logof_Client;
 
 public partial class MainWindow : Window
 {
+    public Uri filePath;
+
     public MainWindow()
     {
         InitializeComponent();
         try
         {
             var temppath = "kaspersons.csv";
-            var result = DataImport.ImportKasAddressList(temppath);
+            var result = DataImport.ImportKasAddressList(new Uri(temppath));
             if (result.Item1)
             {
                 var check_result = AddressCheck.Perform(result.Item2);
@@ -53,4 +56,42 @@ public partial class MainWindow : Window
     {
         throw new NotImplementedException();
     }
+
+    private async void BtnChooseFile_OnClick(object? sender, RoutedEventArgs e)
+    {
+        var topLevel = GetTopLevel(this);
+        var file = await topLevel!.StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
+        {
+            Title = "KAS-CSV-Datei auswählen",
+            AllowMultiple = false,
+            FileTypeFilter = new[]
+            {
+                new FilePickerFileType(".csv-Datei")
+                {
+                    Patterns = new[] { "*.csv" }
+                    //Patterns = new[] { "*" }
+                }
+            }
+        });
+
+        if (file == null) return;
+        TbFilename.Text = file[0].Path.ToString();
+        filePath = file[0].Path;
+    }
+
+    private void BtnCheck_OnClick(object? sender, RoutedEventArgs e)
+    {
+        if (filePath == null) MessageBox.Show(this, "Bitte zunächst eine Datei auswählen", "Datei fehlt");
+        var result = DataImport.ImportKasAddressList(filePath);
+        if (result.Item1)
+        {
+            var check_result = AddressCheck.Perform(result.Item2);
+            foreach (var item in check_result)
+            {
+                Console.WriteLine();
+                Console.Write(item.Item1 + " ");
+                foreach (var error in item.Item2) Console.Write(error + ", ");
+            }
+        }
+    }
 }