How to enable a textbox and wait for criteria to be entered before delete operation in WPF

Question

I am having trouble with deleting a record from my programme. I have a textbox which is disabled by default by the ReadOnly property which is bound to a boolean property of my ViewModel. The textbox permits the user to enter the ID as criteria for the record to be deleted. I have the delete code in my viewmodel, the code suppose to enable the textbox when the delete button is clicked the first time and wait for the user to enter the ID in the textbox and click the delete button the second time to carry out the delete operation. But instead, the code is not working as intended, the code enables the textbox and also run the delete operation without the user entering the ID when the delete button is clicked. In summary, the entire delete code block runs when the user click the delete button. Please how can I make the code to enable the textbox for ID an wait for the user to enter the ID and click the delete button the second time?
This is the code:

        private RelayCommand deleteCommand;

        public RelayCommand DeleteCommand
        {
            get { return deleteCommand; }
        }

        public void Delete()
        {
            MessageBoxResult result = MessageBox.Show("Are you sure you want to delete this record?", "Delete Operation", MessageBoxButton.YesNo, MessageBoxImage.Question,MessageBoxResult.No);
            if(result == MessageBoxResult.No)
            {
                return;
            }
            else
            {
                try
                {
                    IDEnabled = false;

                    var IsDeleted = ObjStudentService.Delete(NewStudent.Id);
                    if (!IsDeleted)
                    {
                        MessageBox.Show("Student Record Deleted", "Delete Operation", MessageBoxButton.OK, MessageBoxImage.Information);
                        LoadData();
                        NewStudent.Id = 0;
                    }
                    else
                    {
                        MessageBox.Show("Unable to Delete Record, ensure you enter the correct ID.", "Delete Operation", MessageBoxButton.OK, MessageBoxImage.Information);

                    }
                }
                catch (Exception ex)
                {

                    MessageBox.Show(ex.Message, "Exception Found", MessageBoxButton.OK, MessageBoxImage.Error);
                }

            }

        }

The "IDEnabled" is the property that disables the ReadOnly property of the ID textbox field so that the user can enter the ID for a particular record to be deleted.

I call the code in the constructor as follows:
public StudentViewModel()
{
ObjStudentService = new StudentService();
LoadData();
NewStudent = new Student();
deleteCommand = new RelayCommand(Delete);

This is my binding in the XAML for the delete button:
<Button x:Name="BtnDelete" Margin="10 0 0 0"
IsTabStop="False"
IsEnabled="{Binding Path=ButtonEnabled}"
Style="{StaticResource MaterialDesignRaisedAccentButton}"
ToolTip="Delete record"
Command="{Binding Path=DeleteCommand}"
Width="75">
Delete
</Button>

Answer 1

Hello @DPlug

I have a code sample that does not is a basic conceptual example on enable/disable a button which will work with other controls such as a TextBox.

Full source found here which is .NET Core 5, C# 9.

RelayCommand

using System;  
using System.Windows.Input;  
  
namespace FrameworkCanExecuteExample.Classes  
{  
    public class RelayCommand : ICommand  
    {  
        private readonly Action<object> _execute;  
        private readonly Func<object, bool> _canExecute;  
  
        public event EventHandler CanExecuteChanged  
        {  
            add => CommandManager.RequerySuggested += value;  
            remove => CommandManager.RequerySuggested -= value;  
        }  
  
        public RelayCommand(Action<object> execute, Func<object, bool> canExecute = null)  
        {  
            _execute = execute;  
            _canExecute = canExecute;  
        }  
  
        public bool CanExecute(object parameter)  
        {  
            return _canExecute is null || _canExecute(parameter);  
        }  
  
        public void Execute(object parameter)  
        {  
            _execute(parameter);  
        }  
    }  
}  

View model

using System;  
using System.ComponentModel;  
using System.Diagnostics;  
using System.Runtime.CompilerServices;  
using System.Windows.Input;  
  
namespace FrameworkCanExecuteExample.Classes  
{  
    public class MainViewModel : INotifyPropertyChanged  
    {  
        private string _connectionString;  
  
        public event PropertyChangedEventHandler PropertyChanged;  
  
        public MainViewModel() => ConfirmCommand = new RelayCommand(Confirm, CanConfirm);  
  
        public string ConnectionString  
        {  
            get => _connectionString;  
            set  
            {  
                _connectionString = value;  
                OnPropertyChanged();  
            }  
        }  
  
        public ICommand ConfirmCommand { get; }  
  
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)  
        {  
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));  
        }  
  
        private void Confirm(object parameter)  
        {  
            Debug.WriteLine("Do something for confirm");  
        }  
  
        private bool CanConfirm(object parameter)  
        {  
            return !string.IsNullOrWhiteSpace(_connectionString);  
        }  
    }  
}  

XAML

<Window  
    x:Class="FrameworkCanExecuteExample.MainWindow"  
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
    xmlns:classes="clr-namespace:FrameworkCanExecuteExample.Classes"  
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"  
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"  
    Title="MainWindow"  
    Width="300"  
    Height="100"  
    WindowStartupLocation="CenterScreen"  
    mc:Ignorable="d">  
  
    <Window.DataContext>  
        <classes:MainViewModel />  
    </Window.DataContext>  
  
    <Grid>  
        <Grid.RowDefinitions>  
            <RowDefinition />  
            <RowDefinition />  
        </Grid.RowDefinitions>  
        <Grid.ColumnDefinitions>  
            <ColumnDefinition />  
            <ColumnDefinition />  
        </Grid.ColumnDefinitions>  
  
        <TextBlock  
            Margin="0,0,10,0"  
            HorizontalAlignment="Right"  
            Text="Connection string:" />  
        <TextBox  
            Grid.Row="0"  
            Grid.Column="1"  
            Text="{Binding Path=ConnectionString, UpdateSourceTrigger=PropertyChanged}" />  
  
        <Button  
            Grid.Row="1"  
            Grid.Column="0"  
            Grid.ColumnSpan="2"  
            Command="{Binding ConfirmCommand}"  
            Content="Confirm" />  
    </Grid>  
</Window>