feat: 新增 CAD 模板图纸服务，用于打开模板、清理匹配参数标注，并提供相关 UI 和字典辅助功能。

Cad/DictionaryHelper.cs

@@ -48,17 +48,26 @@ namespace CadParamPluging.Cad
                 // XRecord 本质上是一个 ResultBuffer 链表
                 // 我们使用 DxfCode.Text (1000) 来存储 key=value 字符串
                 var rb = new ResultBuffer();
+                // serialize user inputs into a single text block
+                var fullString = "";
                 foreach (var item in bag.Items)
                 {
                     if (!string.IsNullOrWhiteSpace(item.Key))
                     {
-                        // 格式: Key=Value
+                        fullString += $"{item.Key}={item.Value ?? string.Empty}\n";
-                        // 也可以分开存储，但简单的 Key=Value 字符串更紧凑
-                        string entry = $"{item.Key}={item.Value ?? string.Empty}";
-                        rb.Add(new TypedValue((int)DxfCode.Text, entry));
                     }
                 }
 
+                // DxfCode.Text has a 255-character limit in AutoCAD ResultBuffer.
+                // We use code 301 (XTextString) and chunk the string to support any length.
+                var temp = fullString;
+                while (temp.Length > 0)
+                {
+                    var chunk = temp.Length > 250 ? temp.Substring(0, 250) : temp;
+                    rb.Add(new TypedValue(301, chunk)); // 301 = DxfCode.XTextString
+                    temp = temp.Length > 250 ? temp.Substring(250) : "";
+                }
+                
                 try 
                 {
                     // Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage($"\n[CadParamPluging] Saving Params: Count={bag.Items.Count}\n");
@@ -114,6 +123,35 @@ namespace CadParamPluging.Cad
                     return bag;
                 }
 
+                var sb = new System.Text.StringBuilder();
+                bool hasCode301 = false;
+                
+                // Read chunks from new format
+                foreach (var tv in rb)
+                {
+                    if (tv.TypeCode == 301)
+                    {
+                        hasCode301 = true;
+                        if (tv.Value is string s)
+                        {
+                            sb.Append(s);
+                        }
+                    }
+                }
+
+                if (hasCode301)
+                {
+                    var fullText = sb.ToString();
+                    foreach (var line in fullText.Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries))
+                    {
+                        var parts = line.Split(new[] { '=' }, 2);
+                        if (parts.Length == 2) bag.Set(parts[0], parts[1]);
+                        else if (parts.Length == 1) bag.Set(parts[0], "");
+                    }
+                    return bag;
+                }
+
+                // Fallback to read from old Code 1 format
                 foreach (var tv in rb)
                 {
                     if (tv.TypeCode == (int)DxfCode.Text)

Cad/TemplateDrawingService.cs

@@ -288,8 +288,17 @@ namespace CadParamPluging.Cad
             var dict = (DBDictionary)tr.GetObject(ent.ExtensionDictionary, OpenMode.ForWrite);
             const string DictName = "CadParamPluging_NoteData";
             
-            // XRecord
+            // XRecord limits text to 255 characters per element.
-            var rb = new ResultBuffer(new TypedValue((int)DxfCode.Text, template));
+            // Split string into 250 character chunks using DxfCode.XTextString (301)
+            var rb = new ResultBuffer();
+            var temp = template;
+            while (temp.Length > 0)
+            {
+                var chunk = temp.Length > 250 ? temp.Substring(0, 250) : temp;
+                rb.Add(new TypedValue(301, chunk)); // 301 = DxfCode.XTextString
+                temp = temp.Length > 250 ? temp.Substring(250) : "";
+            }
+            
             var xrec = new Xrecord { Data = rb };
 
             if (dict.Contains(DictName))
@@ -319,6 +328,20 @@ namespace CadParamPluging.Cad
             var rb = xrec.Data;
             if (rb == null) return null;
 
+            var sb = new System.Text.StringBuilder();
+            bool hasCode301 = false;
+            foreach (var tv in rb)
+            {
+                if (tv.TypeCode == 301)
+                {
+                    hasCode301 = true;
+                    if (tv.Value is string s) sb.Append(s);
+                }
+            }
+
+            if (hasCode301) return sb.ToString();
+
+            // Fallback for old code format
             foreach (var tv in rb)
             {
                 if (tv.TypeCode == (int)DxfCode.Text)
@@ -457,7 +480,7 @@ namespace CadParamPluging.Cad
             Func<string, string> getValueW = (k) => 
             {
                 var val = bag.GetString(k);
-                if (k != null && (k.StartsWith("Hardness", StringComparison.OrdinalIgnoreCase) || k.StartsWith("MarkingContent", StringComparison.OrdinalIgnoreCase)))
+                if (k != null && k.StartsWith("MarkingContent", StringComparison.OrdinalIgnoreCase))
                 {
                     if (bag.GetString(k + "_ShowInNote") == "0") return "__SKIP_NOTE__";
                 }

Common/NoteTemplateEngine.cs

@@ -248,8 +248,8 @@ namespace CadParamPluging.Common
                             }
                             else if (string.Equals(val, "空", StringComparison.OrdinalIgnoreCase))
                             {
-                                // Exception: MarkingContent (标刻内容) should NOT cause line skip
+                                // Exception: MarkingContent (标刻内容) and Hardness (硬度) should NOT cause line skip
-                                if (key == null || !key.StartsWith("MarkingContent", StringComparison.OrdinalIgnoreCase))
+                                if (key == null || !(key.StartsWith("MarkingContent", StringComparison.OrdinalIgnoreCase) || key.StartsWith("Hardness", StringComparison.OrdinalIgnoreCase)))
                                 {
                                     shouldSkip = true;
                                 }
@@ -303,9 +303,9 @@ namespace CadParamPluging.Common
                                 // Handle "空" value
                                 if (string.Equals(v, "空", StringComparison.OrdinalIgnoreCase))
                                 {
-                                    if (string.Equals(key, "MarkingContent", StringComparison.OrdinalIgnoreCase))
+                                    if (key != null && (key.StartsWith("MarkingContent", StringComparison.OrdinalIgnoreCase) || key.StartsWith("Hardness", StringComparison.OrdinalIgnoreCase)))
                                     {
-                                        // MarkingContent -> render empty string
+                                        // MarkingContent / Hardness -> render empty string
                                         // (Separators will be cleaned up later)
                                     }
                                     else

UI/DrawingParamsForm.cs

@@ -427,8 +427,7 @@ namespace CadParamPluging.UI
             }
 
             Control finalCtrl = ctrl;
-            if (string.Equals(def.Key, "Hardness", StringComparison.OrdinalIgnoreCase) ||
+            if (string.Equals(def.Key, "MarkingContent", StringComparison.OrdinalIgnoreCase))
-                string.Equals(def.Key, "MarkingContent", StringComparison.OrdinalIgnoreCase))
             {
                 var flow = new FlowLayoutPanel
                 {
@@ -657,7 +656,7 @@ namespace CadParamPluging.UI
             Func<string, string> getValueW = (k) => 
             {
                 var val = tempBag.GetString(k);
-                if (k != null && (k.StartsWith("Hardness", StringComparison.OrdinalIgnoreCase) || k.StartsWith("MarkingContent", StringComparison.OrdinalIgnoreCase)))
+                if (k != null && k.StartsWith("MarkingContent", StringComparison.OrdinalIgnoreCase))
                 {
                     if (tempBag.GetString(k + "_ShowInNote") == "0") return "__SKIP_NOTE__";
                 }