From c3188c9c0bb558954fc624141d208cf87ee33687 Mon Sep 17 00:00:00 2001
From: sladro <sladro@163.com>
Date: Thu, 25 Dec 2025 15:13:29 +0800
Subject: [PATCH] Initial commit

---
 Common/ParamCatalog.cs  |  2 +-
 UI/DrawingParamsForm.cs | 10 ++++------
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/Common/ParamCatalog.cs b/Common/ParamCatalog.cs
index b3b2509..85f2e9a 100644
--- a/Common/ParamCatalog.cs
+++ b/Common/ParamCatalog.cs
@@ -428,7 +428,7 @@ namespace CadParamPluging.Common
                         Type = ParamValueType.Double,
                         Required = false,
                         DefaultValue = "",
-                        Hint = "自动计算：T=(Φ1-b1+Φ2-a2)/2",
+                        Hint = "自动计算：T=((Φ1+b1)-(Φ2+a2))/2",
                         Order = 590,
                         Group = "尺寸-环形"
                     },
diff --git a/UI/DrawingParamsForm.cs b/UI/DrawingParamsForm.cs
index 7c9b59e..8035110 100644
--- a/UI/DrawingParamsForm.cs
+++ b/UI/DrawingParamsForm.cs
@@ -512,7 +512,7 @@ namespace CadParamPluging.UI
 
                 if (_ctrlMinWallThickness != null)
                 {
-                    _toolTip.SetToolTip(_ctrlMinWallThickness, "自动计算: T=(Φ1-b1+Φ2-a2)/2\n(根据外径Φ1、外径下差b1、内径Φ2、内径上差a2)");
+                    _toolTip.SetToolTip(_ctrlMinWallThickness, "自动计算: T=((Φ1+b1)-(Φ2+a2))/2\n(根据外径Φ1、外径下差b1、内径Φ2、内径上差a2)");
                 }
             }
             else
@@ -545,13 +545,11 @@ namespace CadParamPluging.UI
                 var phi2 = GetNumericValue(KeyInnerDiameter2);
                 var a2 = GetNumericValue(KeyInnerDiameter2TolPlus);
 
-                // T = (Φ1 - b1 + Φ2 - a2) / 2
                 // 注意：b1通常为负数（如-0.5），a2通常为正数（如0.5）
-                // 实际最小壁厚 = ((外径最小) - (内径最大)) / 2
+                // 最小壁厚（径向）：T = ((外径最小) - (内径最大)) / 2
                 // 外径最小 = Φ1 + b1，内径最大 = Φ2 + a2
-                // 最小壁厚 = (Φ1 + b1 - Φ2 - a2) / 2
-                // 但用户公式为 T=(Φ1-b1+Φ2-a2)/2，按此公式计算
-                var t = (phi1 - b1 + phi2 - a2) / 2.0;
+                // T = ((Φ1 + b1) - (Φ2 + a2)) / 2
+                var t = ((phi1 + b1) - (phi2 + a2)) / 2.0;
 
                 if (_ctrlMinWallThickness is NumericUpDown num)
                 {