Fix little bug, close #557.

src/Sudoku.Strategying/Resources/StrategyingResources.resx

@@ -184,6 +184,6 @@
     <value>Single prefer rule: {0} is preferred as primary technique, Hidden Single in rows or columns {1}included</value>
   </data>
   <data name="EliminationCountConstraint" xml:space="preserve">
-    <value>Elimination count rule: a step must contain {0} {1} elimination{2}</value>
+    <value>Elimination count rule: a {3} step must contain {0} {1} elimination{2}</value>
   </data>
 </root>

src/Sudoku.Strategying/Resources/StrategyingResources.zh-cn.resx

@@ -181,6 +181,6 @@
     <value>出数技巧偏好：希望以{0}技巧作为主技巧解题，行列排除{1}在计算之中</value>
   </data>
   <data name="EliminationCountConstraint" xml:space="preserve">
-    <value>删数数量：一个步骤需要有 {0} {1} 个删数结论{2}</value>
+    <value>删数数量：一个{3}步骤需要有 {0} {1} 个删数结论{2}</value>
   </data>
 </root>

src/Sudoku.Strategying/Strategying/Constraints/EliminationCountConstraint.cs

@@ -15,6 +15,13 @@ public sealed partial class EliminationCountConstraint : Constraint, IComparison
 	[StringMember]
 	public int LimitCount { get; set; }
 
+	/// <summary>
+	/// Indicates the technique used.
+	/// </summary>
+	[HashCodeMember]
+	[StringMember]
+	public Technique Technique { get; set; }
+
 	/// <inheritdoc/>
 	[HashCodeMember]
 	[StringMember]
@@ -33,7 +40,7 @@ public override bool Check(ConstraintCheckingContext context)
 		var @operator = Operator.GetOperator<int>();
 		foreach (var step in context.AnalyzerResult)
 		{
-			if (@operator(LimitCount, step.Conclusions.Length))
+			if (step.Code == Technique && @operator(LimitCount, step.Conclusions.Length))
 			{
 				return true;
 			}
@@ -52,6 +59,7 @@ public override string ToString(CultureInfo? culture = null)
 			ResourceDictionary.Get("EliminationCountConstraint", culture),
 			Operator.GetOperatorString(),
 			LimitCount,
-			LimitCount != 1 ? string.Empty : ResourceDictionary.Get("NounPluralSuffix", culture)
+			LimitCount != 1 ? string.Empty : ResourceDictionary.Get("NounPluralSuffix", culture),
+			Technique.GetName(culture)
 		);
 }

src/SudokuStudio/Views/Pages/GeneratedPuzzleConstraintPage.xaml

@@ -48,7 +48,7 @@
 						</MenuFlyoutItem>
 						<MenuFlyoutItem Text="{m:R Key=GeneratedPuzzleConstraintPage_EliminationCountConstraint}" Click="MenuFlyoutItem_Click">
 							<MenuFlyoutItem.Tag>
-								<con:EliminationCountConstraint LimitCount="5" Operator="GreaterThanOrEqual" />
+								<con:EliminationCountConstraint Technique="LockedPair" LimitCount="5" Operator="GreaterThanOrEqual" />
 							</MenuFlyoutItem.Tag>
 						</MenuFlyoutItem>
 						<MenuFlyoutItem Text="{m:R Key=GeneratedPuzzleConstraintPage_DifficultyLevelConstraint}" Click="MenuFlyoutItem_Click">

src/SudokuStudio/Views/Pages/GeneratedPuzzleConstraintPage.xaml.cs

@@ -706,9 +706,9 @@ static string getTechniqueString(TechniqueSet techniques)
 		};
 	}
 
-	private SettingsCard? Create_EliminationCount(EliminationCountConstraint constraint)
+	private SettingsExpander? Create_EliminationCount(EliminationCountConstraint constraint)
 	{
-		if (constraint is not { LimitCount: var limitCount, Operator: var @operator })
+		if (constraint is not { LimitCount: var limitCount, Operator: var @operator, Technique: var technique })
 		{
 			return null;
 		}
@@ -723,15 +723,38 @@ static string getTechniqueString(TechniqueSet techniques)
 		//
 		var limitCountControl = LimitCountControl(limitCount, constraint);
 
+		//
+		// chosen techniques displayer
+		//
+		var displayerControl = new TextBlock
+		{
+			MaxWidth = 400,
+			TextWrapping = TextWrapping.WrapWholeWords,
+			VerticalAlignment = VerticalAlignment.Center,
+			Text = $"{technique.GetName(App.CurrentCulture)}{ResourceDictionary.Get("_Token_Comma2", App.CurrentCulture)}"
+		};
+
+		//
+		// technique view
+		//
+		var techniqueControl = new TechniqueView { SelectionMode = TechniqueViewSelectionMode.Single, SelectedTechniques = [technique] };
+		techniqueControl.CurrentSelectedTechniqueChanged += (_, e) =>
+		{
+			var technique = e.Technique;
+			constraint.Technique = technique;
+			displayerControl.Text = $"{technique.GetName(App.CurrentCulture)}{ResourceDictionary.Get("_Token_Comma2", App.CurrentCulture)}";
+		};
+
 		return new()
 		{
 			Header = ResourceDictionary.Get("GeneratedPuzzleConstraintPage_EliminationCount", App.CurrentCulture),
 			Margin = DefaultMargin,
+			Items = { techniqueControl },
 			Content = new StackPanel
 			{
 				Orientation = Orientation.Horizontal,
 				Spacing = 3,
-				Children = { operatorControl, limitCountControl }
+				Children = { displayerControl, operatorControl, limitCountControl }
 			},
 			Tag = constraint
 		};