增强条码元素和自由表格元素的渲染逻辑，支持更多条码格式和文本边框样式。新增条码渲染工具，优化打印预览窗口的打印机选择功能，提升用户体验和打印模板的灵活性。

yy-admin-master/YY.Admin/ViewModels/Print/PrintTemplateListViewModel.cs

@@ -14,6 +14,7 @@ namespace YY.Admin.ViewModels.Print;
 public class PrintTemplateListViewModel : BaseViewModel
 {
     private readonly IPrintTemplateService _printTemplateService;
+    private readonly IPrintDotService _printDotService;
     private readonly IEventAggregator _eventAggregator;
     private SubscriptionToken? _changeToken;
 
@@ -21,6 +22,32 @@ public class PrintTemplateListViewModel : BaseViewModel
 
     public ObservableCollection<PrintTemplate> Templates { get; } = new();
 
+    // ── PrintDot 打印机选择 ────────────────────────────────────────────────
+    public ObservableCollection<PrintDotPrinter> Printers { get; } = new();
+
+    private bool _suppressPrinterSave;
+    private PrintDotPrinter? _selectedPrinter;
+    public PrintDotPrinter? SelectedPrinter
+    {
+        get => _selectedPrinter;
+        set
+        {
+            if (!SetProperty(ref _selectedPrinter, value)) return;
+            if (_suppressPrinterSave) return;
+            // 持久化用户选择，预览窗口和后续会话使用
+            var s = PrintDotSettings.Load();
+            s.SelectedPrinter = value?.Name ?? string.Empty;
+            s.Save();
+        }
+    }
+
+    private string _printerStatus = string.Empty;
+    public string PrinterStatus
+    {
+        get => _printerStatus;
+        set => SetProperty(ref _printerStatus, value);
+    }
+
     private string _statusMessage = string.Empty;
     public string StatusMessage
     {
@@ -52,14 +79,17 @@ public class PrintTemplateListViewModel : BaseViewModel
     public DelegateCommand SearchCommand { get; }
     public DelegateCommand ResetCommand { get; }
     public DelegateCommand<PrintTemplate> PreviewCommand { get; }
+    public DelegateCommand RefreshPrintersCommand { get; }
 
     public PrintTemplateListViewModel(
         IPrintTemplateService printTemplateService,
+        IPrintDotService printDotService,
         IEventAggregator eventAggregator,
         IContainerExtension container,
         IRegionManager regionManager) : base(container, regionManager)
     {
         _printTemplateService = printTemplateService;
+        _printDotService = printDotService;
         _eventAggregator = eventAggregator;
 
         SearchCommand = new DelegateCommand(ApplyFilter);
@@ -71,6 +101,7 @@ public class PrintTemplateListViewModel : BaseViewModel
             FilterCategory = null;
             ApplyFilter();
         });
+        RefreshPrintersCommand = new DelegateCommand(async () => await RefreshPrintersAsync(verbose: true));
 
         _changeToken = _eventAggregator
             .GetEvent<PrintTemplateChangedEvent>()
@@ -79,6 +110,51 @@ public class PrintTemplateListViewModel : BaseViewModel
         // 先用缓存立即填充，再后台静默刷新
         ShowCached();
         _ = RefreshSilentlyAsync();
+
+        // 后台静默连接 PrintDot 桥接器，初次加载打印机
+        _ = RefreshPrintersAsync(verbose: false);
+    }
+
+    /// <summary>
+    /// 通过 PrintDot 桥接器拉取打印机列表，与后端 web 列表页的 fetchPrintDotPrinters 行为对齐。
+    /// </summary>
+    private async Task RefreshPrintersAsync(bool verbose)
+    {
+        if (verbose) PrinterStatus = "刷新打印机中...";
+        var savedName = PrintDotSettings.Load().SelectedPrinter;
+        try
+        {
+            var list = await _printDotService.GetPrintersAsync();
+            System.Windows.Application.Current.Dispatcher.Invoke(() =>
+            {
+                Printers.Clear();
+                foreach (var p in list) Printers.Add(p);
+
+                // 选中规则：上次保存 > 系统默认 > 首台
+                var match = list.FirstOrDefault(p => p.Name == savedName)
+                            ?? list.FirstOrDefault(p => p.IsDefault)
+                            ?? (list.Count > 0 ? list[0] : null);
+
+                _suppressPrinterSave = true;
+                SelectedPrinter = match;
+                _suppressPrinterSave = false;
+
+                PrinterStatus = list.Count > 0 ? $"共 {list.Count} 台打印机" : "未检测到打印机";
+            });
+        }
+        catch (Exception ex)
+        {
+            System.Windows.Application.Current.Dispatcher.Invoke(() =>
+            {
+                Printers.Clear();
+                _suppressPrinterSave = true;
+                SelectedPrinter = null;
+                _suppressPrinterSave = false;
+                PrinterStatus = verbose
+                    ? $"PrintDot 未连接：{ex.Message}"
+                    : "PrintDot 未连接";
+            });
+        }
     }
 
     private void ShowCached()
@@ -192,7 +268,7 @@ public class PrintTemplateListViewModel : BaseViewModel
             catch { /* 保持 json 为 null，预览窗口显示"尚未设计" */ }
         }
 
-        var win = new PrintPreviewWindow(template, json)
+        var win = new PrintPreviewWindow(template, json, _printDotService, SelectedPrinter?.Name)
         {
             Owner = Application.Current.MainWindow
         };