textinput mvvm detection

PacticeSolution/MVVMTextInputDetection/ViewModel/CalculateViewModel.cs

@@ -0,0 +1,46 @@
+using MVVMTextInputDetection.Model;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+
+namespace MVVMTextInputDetection.ViewModel
+{
+    class CalculateViewModel : INotifyPropertyChanged
+    {
+        public Calculate CalculateModel { get; set; }
+
+        public event PropertyChangedEventHandler? PropertyChanged;
+
+        public CalculateViewModel()
+        {
+            this.CalculateModel = new Calculate();
+        }
+
+        public int Number
+        {
+            get { return this.CalculateModel.Number; }
+            set
+            {
+                CalculateModel.Number = value;
+                OnPropertyChanged("Number");
+
+                CheckNumberRange(this.CalculateModel.Number);
+            }
+        }
+
+        private void CheckNumberRange(int number)
+        {
+            if (number > 99 || number < 0)
+                MessageBox.Show("Number range exceeded!");
+        }
+
+        protected void OnPropertyChanged(string propertyName)
+        {
+            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+    }
+}