принятая 1 лаба

TestView/Form1.cs

@@ -53,23 +53,10 @@ namespace TestView
 
 		private void buttonCheck_Click(object sender, EventArgs e)
 		{
-			try
-			{
-				if (input_text.Element.Equals("Range exeption"))
-					throw new TextBoundsNotSetExeption("Äèàïàçîí íå çàäàí");
-				if (input_text.Element.Equals("Value exeption"))
-					throw new TextOutOfBoundsExeption("Ñëîâî âíå äèàïàçîíà");
-				
-				MessageBox.Show(input_text.Element, "×åðåç ñâîéñòâî");
-			}
-			catch (TextBoundsNotSetExeption ex)
-			{
-				MessageBox.Show(ex.Message);
-			}
-			catch (TextOutOfBoundsExeption ex)
-			{
-				MessageBox.Show(ex.Message);
-			}
+			if (input_text.Element == null)
+				MessageBox.Show(input_text.Error);
+			else MessageBox.Show(input_text.Element, "×ĺđĺç ńâîéńňâî");
+			
 		}
 
 		private void buttonIerarhy_Click(object sender, EventArgs e)

ViewComponents/Input_text.cs

@@ -19,18 +19,19 @@ namespace ViewComponents
 			InitializeComponent();
 		}
 
+		public String Error { get; set; } = String.Empty;
+
 		public event Action<string?> ItemChange;
 		
 		public int MinLen { get; set; } = -1;
 		public int MaxLen { get; set; } = -1;
 		
-		public string Element
+		public string? Element
 		{
 			get
 			{
-				if (MinLen < 0 || MaxLen < 0) return "Range exeption";
-				if (textBox1.Text.Length < MinLen || textBox1.Text.Length > MaxLen) return "Value exeption";
-				return textBox1.Text;
+				if (CheckValue()) return textBox1.Text;
+				return null;
 			}
 			set
 			{
@@ -38,7 +39,23 @@ namespace ViewComponents
 			}
 		}
 
-		
+		public bool CheckValue()
+		{
+			Error = string.Empty;
+			if (MinLen < 0 || MaxLen < 0)
+			{
+				Error = "Bounds error";
+				return false;
+			}
+
+			if (textBox1.Text.Length < MinLen || textBox1.Text.Length > MaxLen)
+			{
+				Error = "Value error";
+				return false;
+			}
+
+			return true;
+		}
 
 		private void textBox1_TextChanged(object sender, EventArgs e)
 		{

ViewComponents/MyTreeView.cs

@@ -34,7 +34,7 @@ namespace ViewComponents
 
 		public T? getSelecetedNodeValue<T>()
 		{
-			if (treeView.SelectedNode == null || treeView.SelectedNode.Nodes.Count > 0) return default(T);
+			if (treeView.SelectedNode == null || treeView.SelectedNode.Nodes.Count > 0) throw new ArgumentException();
 
 			TreeNode? node = treeView.SelectedNode;
 
@@ -53,7 +53,7 @@ namespace ViewComponents
 				node = node.Parent;
 			}
 
-			return item != null ? (T)item : default(T);
+			return (T)item;
 		}
 
 		public void setHierarchy(List<(string, bool)> fields)