CODEWITHSUNDEEP
windows-phone-7windows-phone-8windows-phone
MikePR
MikePR

Reputation: 2986

How to use the CommandParameter in XAML

I am a little lost in how to use the CommandParameter in XAML. I am trying to bind a TextBox and a Button.

This my XAML code:

<TextBox x:Name="txtCity" Height="70"
         VerticalAlignment="Top"/>
<Button x:Name="btnCity"
        Content="Get"
        Background="CornflowerBlue"
        Height="70"
        Command="{Binding GetweatherCommand}"
        CommandParameter="{Binding ElementName=txtCity, Path=Text}"/>

In my ViewModel class I have the following to handle the clic action:

ActionCommand getWeatherCommand;          //ActionCommand derivides from ICommand
public ActionCommand GetWeatherCommand
{
        get
        {
            if (getClimaCommand != null)
            {
                getClimaCommand = new ActionCommand(() =>
                    {
                        serviceModel.getClima("????");
                    });
            }

            return getWeatherCommand;
        }
 }

My ActionCommand class:

public class ActionCommand : ICommand
{
    Action action;
    public ActionCommand(Action action)
    {
        this.action = action;
    }

    public bool CanExecute(object parameter)
    {
        return true;
    }

    public event EventHandler CanExecuteChanged;

    public void Execute(object parameter)
    {
        action();
    }
}

When I debug, the parameters in the Execute and CanExecute methods have the proper value. However, I guess the problem is in the method from the ViewClass (GetWeatherCommand). I can't figure out how to pass the parameter.

So, based on the above, does anyone know how can I pass the parameter to the method that will be executed?

Upvotes: 1

Views: 6735

Answers (1)

Richard Szalay
Richard Szalay

Reputation: 84724

ActionCommand.Execute is ignoring the command parameter. Try this:

public class ActionCommand<TParam> : ICommand
{
    Action<TParam> action;
    public ActionCommand(Action<TParam> action)
    {
        this.action = action;
    }

    public bool CanExecute(object parameter)
    {
        return true;
    }

    public event EventHandler CanExecuteChanged;

    public void Execute(object parameter)
    {
        action((TParam)parameter);
    }
}

And then:

getClimaCommand = new ActionCommand<string>(param =>
    {
        serviceModel.getClima(param);
    });

Upvotes: 3

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