Fighting with binding

Question

I have some checkboxes that are defined like this:

(This is the checkbox that you can click on to check/uncheck all the other checkboxes, let's call this *)

<CheckBox Content="Check all" Grid.Column="1" Grid.Row="1" Margin="200 7 0 0" Name="IsCheckedCheckAll" 
                      Checked="IsCheckedCheckAll_Checked" Unchecked="IsCheckedCheckAll_Checked" />

And the C# code for the above, is:

if (IsCheckedCheckAll.IsChecked == true)
        {
            IsCheckedCheckAll.Content = "Uncheck all";
        }
        else 
        {                
            IsCheckedCheckAll.Content = "Check all";
        }

(And below is the checkbox that depends on the one above, and I have several others like this, lets call this **)

 <CheckBox Name="Exc2" Grid.Column="1" Grid.Row="3" Margin="200 7 0 0" IsChecked="{Binding IsChecked, ElementName=IsCheckedCheckAll, Mode=OneWay}" />

The thing to notice, is the binding. Say I have 10 other checkboxes that have registered to the binding. I can then check the * checkbox, so that all the others that have a binding gets checked. Now let's say that I want to uncheck the ** checkbox. This will still be noted as checked, so the value that is inserted in the database will be wrong.

My C# code for determining if the checkbox is checked looks like this:

bool ex2 = (bool) Exc2.IsChecked

This value will return false, if Exc1 checkbox indeed is checked, but the checkbox that do the binding is unchecked. This might seem like an easy fix, but I can't come up with it. I can fix it if I stop using bindings, but I want to use binding. Maybe I'm just using the binding in a wrong way?

I tried to explain the problem as good as I can, I hope it's understandable

Answer 1

The problem was that I had copy&past my code, so it looked like this:

bool ex1 = (bool) Exc1.IsChecked, ex2 = (bool) Exc1.IsChecked, ex3 = (bool) Exc1.IsChecked,
        ex4 = (bool) Exc1.IsChecked, ex5 = (bool) Exc1.IsChecked;

Instead of:

bool ex1 = (bool) Exc1.IsChecked, ex2 = (bool) Exc2.IsChecked, ex3 = (bool) Exc3.IsChecked,
        ex4 = (bool) Exc4.IsChecked, ex5 = (bool) Exc5.IsChecked;

Notice that the top code sets all the declarations of ex1, e2, ex3... to Exc1.Ischecked. This of course didn't work as expected, and I ended up using almost an hour finding out what was the problem.

Lesson learned. DON'T use c&p blindly :D

Answer 2

Things are working as expected for me. See sample below:

<Window x:Class="WpfApplication2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Window.Resources>
    <Style x:Key="SomeStyle">
        <Style.Triggers>
            <Trigger Property="CheckBox.IsChecked" Value="True">
                <Trigger.Setters>
                    <Setter Property="CheckBox.Content" Value="Uncheck all"></Setter>
                </Trigger.Setters>
            </Trigger>
            <Trigger Property="CheckBox.IsChecked" Value="False">
                <Trigger.Setters>
                    <Setter Property="CheckBox.Content" Value="Check all"></Setter>
                </Trigger.Setters>
            </Trigger>
        </Style.Triggers>
    </Style>
</Window.Resources>
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition/>
        <RowDefinition/>
        <RowDefinition/>
        <RowDefinition/>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>
    <CheckBox Grid.Column="1" Grid.Row="0" Margin="200 7 0 0" Name="IsCheckedCheckAll" Style="{StaticResource SomeStyle}"/>
    <CheckBox Name="Exc2" Grid.Column="1" Grid.Row="1" Margin="200 7 0 0" IsChecked="{Binding IsChecked, ElementName=IsCheckedCheckAll, Mode=OneWay}" />
    <CheckBox Name="Exc3" Grid.Column="1" Grid.Row="2" Margin="200 7 0 0" IsChecked="{Binding IsChecked, ElementName=IsCheckedCheckAll, Mode=OneWay}" />
    <Button Grid.Column="1" Grid.Row="3" Content="{Binding IsChecked, ElementName=IsCheckedCheckAll}" Click="ButtonBase_OnClick"></Button>
</Grid>
</Window>

namespace WpfApplication2
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
    {
        MessageBox.Show(((bool) Exc2.IsChecked).ToString());
    }
}
}

Also you can use Styles and Triggers to auto change the text for * checkbox.