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

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>