How to pass multiple parameters to WPF Command with a Button?

Question

Currently my code looks like:

<Button Command="{Binding DrinkCommand}" CommandParameter="Capuccino" Style="{StaticResource DrinkButton}">
    <TextBlock>Capuccino</TextBlock>
</Button>
<Button Command="{Binding DrinkWithSugarCommand}" CommandParameter="Capuccino" Style="{StaticResource DrinkButton}">
    <TextBlock>Capuccino + sugar</TextBlock>
</Button>

You can see that I have a different RelayCommand for a capuccino with sugar and without sugar.

I would like to add the option to add extra milk. However than I will get:

DrinkCommand,

DrinkWithSugarCommand,

DrinkWithMilkCommand,

DrinkWithSugarAndMilkCommand.

Is there a way to let the DrinkCommand know that I want the drink (cappucino) with sugar and/or milk?

Why not pass the string `"Capuccino + sugar"` to the CommandParameter? — Clemens, Nov 05 '19 at 11:24
That's an option, however than I have to split the string in the DrinkCommand. I hoped there would be a more elegant option — Frogical, Nov 05 '19 at 11:26
Instead of setting `Capuccino + sugar` as the Button's Content, you could also just write `Content="Capuccino + sugar"`, and move `Command="{Binding DrinkCommand}"` and `CommandParameter="{Binding Content, RelativeSource={RelativeSource Self}}"` into the Button Style. — Clemens, Nov 05 '19 at 11:27
You could use `MultiBinding`, [SO answer](https://stackoverflow.com/a/1350995/2029607). Or even an array [Another SO Answer](https://stackoverflow.com/a/55194890/2029607). — XAMlMAX, Nov 05 '19 at 11:38

score 5 · Accepted Answer · answered Nov 05 '19 at 11:31

You could create a class to hold your different command parameters and use it like:

<Button Content="Capuccino + sugar" Command="{Binding DrinkCommand}">
    <Button.CommandParameter>
        <wpfapp1:MyCommandParameters Milk="false" Sugar="true"/>
    </Button.CommandParameter>
</Button>

Your class would look like

public class MyCommandParameters {
    public bool Milk { get; set; }
    public bool Sugar { get; set; }
}

and you could use it in your command code where it will be passed as argument.

LPGTE SOFTS · Answer 2 · 2019-11-05T14:59:48.873

It exsists several way to reveal your need, following the use of combobox to select the type of command and a button to send the request:

Xaml

    <Window x:Class="CommandNameSpace.Views.MainWindowView"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                 xmlns:d="http://schemas.microsoft.com/expression/blend/2008">

        <Grid x:Name="MainGrid">
            <Canvas >
                <StackPanel VerticalAlignment="Center">
                    <ComboBox  ItemsSource="{Binding LisCommandType, Mode=TwoWay}"  SelectedItem="{Binding SelectedCommandType, Mode=TwoWay}" >
                        <ComboBox.ItemTemplate>
                            <DataTemplate>
                                <TextBlock Text="{Binding Value}"/>
                            </DataTemplate>
                        </ComboBox.ItemTemplate>
                    </ComboBox>
                </StackPanel>

           <StackPanel VerticalAlignment="Center">
                    <Button x:Name="cmdCommand" IsDefault="True" Content="Commander" Command = "{Binding OrderCommand}" CommandParameter = "null"/>
           </StackPanel>
        </Canvas >
       </Grid>
    </Window >

Main Class

namespace CommandNameSpace
{
   public class MainCalss
   {
        public BaseCommand<string> OrderCommand { get; private set; }
        private Dictionary<string, string> _selectedCommandType = new Dictionary<string, string>();
        private KeyValuePair<string, string> _selectedLanguage;

        public ServicesControlViewModel()
        {
            OrderCommand = new BaseCommand<string>(cmdOrderCommand);

            LisCommandType.Add("DrinkCommand", "Drink");
            LisCommandType.Add("DrinkWithSugarCommand", "Drink With Sugar");
            LisCommandType.Add("DrinkWithMilkCommand", "Drink With Milk");
            LisCommandType.Add("DrinkWithSugarAndMilkCommand", "Drin kWith Sugar And Milk");

            SelectedCommandType = new KeyValuePair<string, string>("DrinkCommand", "Drink");
        }

        public Dictionary<string, string> LisCommandType
        {
            get
            {
            return _liscommandType;
            }
            set
            {
            _liscommandType = value;
            }
        }

        public KeyValuePair<string, string> SelectedCommandType
        {
            get
            {
            return _selectedCommandType;
            }
            set
            {
            _selectedCommandType = value;
            }
        }

        private void cmdOrderCommand(string paramerter)
        {
            switch (SelectedCommandType)
            {
                case "DrinkCommand":
                    Instruction for DrinkCommand type

                    break;
                case "DrinkWithSugarCommand":
                    Instruction for DrinkCommand type

                    break;
                case "DrinkWithMilkCommand":
                    Instruction for DrinkCommand type

                    break;
                case "DrinkWithSugarAndMilkCommand":
                    Instruction for DrinkCommand type

                    break;
            }
        }
}

Call Of View

MainCalss MainCl = new MainCalss();
MainWindowView MainV = new MainWindowView();
MainV.Datacontext = MainCl;
MainV.ShowDialog();

Cordialy

score 0 · Answer 3 · answered Nov 06 '19 at 08:52

you can use a single command with a single parameter which can be parsed in command method.

Such parameter can be of enum type, which declared witrh Flags attribute:

[Flags]
private enum Tastes
{
    None = 0,
    Sugar = 1,
    Milk = 1 << 1,
    Capuccino = 1 << 2
}

xaml:

<Button Command="{Binding DrinkCommand}" CommandParameter="Capuccino" 
        Content="Capuccino" Style="{StaticResource DrinkButton}"/>
<Button Command="{Binding DrinkCommand}" CommandParameter="Capuccino, Sugar"
        Content="Capuccino + sugar" Style="{StaticResource DrinkButton}"/>
<Button Command="{Binding DrinkCommand}" CommandParameter="Milk" 
        Content="Milk" Style="{StaticResource DrinkButton}"/>
<Button Command="{Binding DrinkCommand}" CommandParameter="Milk, Sugar" 
        Content="Milk + sugar" Style="{StaticResource DrinkButton}"/>

command method:

private void Drink(object args)
{
    string x = (string)args;
    if (x != null)
    {
        Tastes t = (Tastes)Enum.Parse(typeof(Tastes), x);
        if (t.HasFlag(Tastes.Sugar))
        {
            Console.WriteLine("sweet");
        }
    }
}

How to pass multiple parameters to WPF Command with a Button?

3 Answers3