Change the enable of a button

Question

I have a command.cs, that check if all my input fields are not empty and base on that it is suppose to enable he button.

This is the command

public class SendDataCommand : ICommand {  

    public PrpertiesWindowViewModel _ViewModel { get; set; }  

    public SendDataCommand(PrpertiesWindowViewModel viewModel) {  
        _ViewModel = viewModel;  
    }  

    public event EventHandler? CanExecuteChanged {  
        add { CommandManager.RequerySuggested += value; }  
        remove { CommandManager.RequerySuggested -= value; }  
    }  

    public bool CanExecute(object? parameter) {  
        return _ViewModel.EnableButton;  
    }  

    public void Execute(object? parameter) {  
        _ViewModel.SendToServer();  
    }  
}  

This is my VM

[AddINotifyPropertyChangedInterface]
public class PrpertiesWindowViewModel {

    public Building? Building { get; set; }  

    public SendCommand? SendCommand { get; set; }  

    public PrpertiesWindowViewModel() {  

        SendCommand = new SendCommand(this);  

    }  

    public void SendData(Building building) {  
          
         
    }  
}  

UI

<Window.DataContext>  
        <vm:PrpertiesWindowViewModel />  
    </Window.DataContext>  
  
    <StackPanel>  
        <TextBox  
            materialDesign:HintAssist.Hint="Name of the building"  
            materialDesign:HintAssist.IsFloating="True"  
            Text="{Binding Building.Name, UpdateSourceTrigger=PropertyChanged}" />  
        <TextBox  
            x:Name="DescTx"  
            materialDesign:HintAssist.Hint="Description"  
            materialDesign:HintAssist.IsFloating="True"  
            Text="{Binding Building.Desc, UpdateSourceTrigger=PropertyChanged}" />  
        <TextBox  
            x:Name="RoomsTx"  
            materialDesign:HintAssist.Hint="Rooms"  
            materialDesign:HintAssist.IsFloating="True"  
            Text="{Binding Building.Rooms, UpdateSourceTrigger=PropertyChanged}" />  
        <TextBox  
            x:Name="AddressTx"  
            materialDesign:HintAssist.Hint="Address"  
            materialDesign:HintAssist.IsFloating="True"  
            Text="{Binding Building.Address, UpdateSourceTrigger=PropertyChanged}" />  
        <Button Command="{Binding SendCommand}"/>  

I am using MVVM, so I do not have/want code in my xaml.cs(CodeBehind)

app https://github.com/eduardoagr/RsidentsManager

Answer 1

Hi,@Eduardo Gomez . Welcome Microsoft Q&A.
For the problem of disabling the button when the text box in the window is null or empty, you could try the following method.

Xaml:

   <Border Padding="20" Width="300">  
            <StackPanel>  
                <TextBox  
                     materialDesign:HintAssist.Hint="Name of the building"  
                     materialDesign:HintAssist.IsFloating="True"  
                     Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />  
                <TextBox  
                     materialDesign:HintAssist.Hint="Address"  
                     materialDesign:HintAssist.IsFloating="True"  
                     Text="{Binding Address,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />  
                <Button Content="Save"  IsEnabled="{Binding IsEnabled}"   Command="{Binding ButtonCommand}"  />  
            </StackPanel>  
        </Border>  

CodeBehind:

214713-9.txt
The result:

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