WPF CommandParameter in Textbox

Question

I am using MVVM pattern and i have a textbox in parent window and want to send some text to the popup window which will appear on Textchanged.

I tried using commandparameter but it is not working for me.

Please help..

Thanks Sharath

Solution 1

If i want the command to be executed if the user presses enter, i like to use this. Note the clever use of the IsDefault Binding :-)

<TextBox x:Name="inputBox"/>
<Button Command="{Binding CutCommand}" 
        CommandParameter="{Binding Text, ElementName=inputBox}" 
        Content="Cut" 
        IsDefault="{Binding IsFocused, ElementName=inputBox}" />

If you don't want the button to be visible, you can set its visibility to collapsed of course. I think it'll still execute the command if you hit enter.

Solution 2

This code works for me

<UserControl x:Class="Test"
             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"
             mc:Ignorable="d" 
             Height="Auto" Width="Auto">
  <UserControl.InputBindings>
    <KeyBinding Key="Enter" Command="{Binding ScanCommand}" CommandParameter="{Binding Text, ElementName=tbBarcode}"/>
  </UserControl.InputBindings>
  <Grid Name="LayoutRoot">
    <TextBox x:Name="tbBarcode" Height="23"/>
  </Grid>
</UserControl>

Solution 3

What have you tried? This code works for me:

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <Window.CommandBindings>
        <CommandBinding Command="Cut" Executed="CommandBinding_Executed" />
    </Window.CommandBindings>
    <StackPanel>
        <TextBox x:Name="textBox1" />
        <Button Command="Cut" 
                CommandParameter="{Binding Text,ElementName=textBox1}" 
                Content="Cut" />
    </StackPanel>
</Window>

With this event handler:

private void CommandBinding_Executed(object sender, ExecutedRoutedEventArgs e)
{
    MessageBox.Show(e.Parameter.ToString());
}

Comments

[Admin]

I want to use textbox textchanged or when user clicks enter on textbox from keyboard. Don't want to button.

[Matt Hamilton]

If you're using a Command then you have to use an ICommandSource like a Button. Commands aren't the same as event handlers.

[Admin]

Can i do the same for listbox. I mean when i Double click on the listbox items. The button click even should be raised.

[Botz3000]

I don't know. I invoked the command manually in code-behind for that. I'm pretty new to xaml though, so who knows.

[Pavlin Marinov]

I think setting button's visibility to hidden (not collapse) will do the job.

[nulltron]

@Botz3000 you're the real mvp