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lib/api/dto/plan_detail_dto.dart

@@ -24,6 +24,21 @@ class PlanStepDto {
     stepExplain = json["step_explain"];
     stepStatus = json["step_status"];
   }
+
+  /// 浅拷贝（只复制字段，不生成新 id）
+  PlanStepDto copyWith({
+    int? id,
+    String? stepIcon,
+    String? stepContent,
+    String? stepExplain,
+    int? stepStatus,
+  }) => PlanStepDto(
+    id: id ?? this.id,
+    stepIcon: stepIcon ?? this.stepIcon,
+    stepContent: stepContent ?? this.stepContent,
+    stepExplain: stepExplain ?? this.stepExplain,
+    stepStatus: stepStatus ?? this.stepStatus,
+  );
 }
 
 class PlanDetailDto {