Question

I have a toggle buttons in my wpf application. On startup the togglebutton must be set.

My Xaml File:

<ToggleButton Content="AUD Reset" IsChecked="True" Height="23" HorizontalAlignment="Center" Margin="0" Name="button4" Command="{Binding Path=ConnectCommand}" VerticalAlignment="Center" Width="100" />                   

On togglebutton click I want to check for the toggle state in my viewmodel class and if it returns true then I want to do the following operation:

My ViewModel Class:

private ICommand mUpdater;
    public ICommand ConnectCommand
    {
        get
        {
            if (mUpdater == null)
                mUpdater = new DelegateCommand(new Action(ConnectToSelectedDevice), new Func<bool>(ConnectCanExecute));

            return mUpdater;
        }
        set
        {
            mUpdater = value;
        }
    }

    public bool ConnectCanExecute()
    {
        return true;
    }

    public void ConnectToSelectedDevice()
    {
        mComm.SetAddress(0x40);
        Byte[] buffer= new Byte[2];
        buffer[0] = 0x24;
        buffer[1] = 0x00;

        if(Check if button togglestate is set, if true then)
        {
         buffer[1] = 0x04;
        }
        mComm.WriteBytes(2, buffer);
    }

How can I check whether the togglebutton is checked or not in my viewmodel and perform the above statements.

Please help!!

Answer 1

You can add IsChecked property to your ViewModel and bind it with ToggleButton.IsChecked dependency property:

public bool IsChecked {
   get { return this.isChecked; }
   set {
      this.isChecked = value;
      this.OnPropertyChanged("IsChecked");
   }
}

<ToggleButton Content="AUD Reset" IsChecked="{Binding Path=IsChecked}" Height="23" HorizontalAlignment="Center" Margin="0" Name="button4" Command={Binding Path=ConnectCommand} VerticalAlignment="Center" Width="100" />    

Then check its state:

public void ConnectToSelectedDevice()
{
    mComm.SetAddress(0x40);
    Byte[] buffer= new Byte[2];
    buffer[0] = 0x24;
    buffer[1] = 0x00;

    if(this.IsChecked)
    {
     buffer[1] = 0x04;
    }
    mComm.WriteBytes(2, buffer);
}

And finally, initialize IsChecked property in ViewModel’s constructor:

public ViewModel() {
   this.IsChecked = true;
}