Question

I am working on a WPF where I need to dynamically generate Checkboxes 16 times.

XAML:

<Checkboxes Height="14" Command="{Binding CheckboxesGen}" Margin="0" Name="checkBox1" Grid.Column="0" VerticalAlignment="Center" HorizontalAlignment="Center" />

Using above way, It will be inefficient if I write down this Checkboxes 16 times and have individual Button Click Command for them. I would ideally want to generate them 16 times and have one common method in my viewmodel class as follows:

private ICommand mCheckboxesGen;
    public ICommand CheckboxesGen
    {
        get
        {
            if (mCheckboxesGen== null)
                mCheckboxesGen= new DelegateCommand(new Action(mCheckboxesGenExecuted), new Func<bool>(mCheckboxesGenCanExecute));

            return mCheckboxesGen;
        }
        set
        {
            mCheckboxesGen= value;
        }
    }

    public bool mCheckboxesGenCanExecute()
    {
        return true;
    }

    public void mCheckboxesGenExecuted(some INDEX parameter which gives me selected Checkboxes )
    {
        // Have a common method here which performs operation on each Checkboxes click based on INDEX which determines which Checkboxes I have selected
    }

I had faced the same situation in my C++ app. I had done it in my C++ app as follows:

for(int j = 0; j < 16; j ++)
    {
        m_buttonActiveChannels[j] = new ToggleButton();
        addAndMakeVisible(m_buttonActiveChannels[j]);
        m_buttonActiveChannels[j]->addButtonListener(this);
    }

//Checking which Checkboxes is clicked
unsigned bit = 0x8000;
for(int i = 15; i >= 0; i--)
{
    if(0 != (value & bit)) //Value has some hardcoded data
    {
        m_buttonActiveChannels[i]->setToggleState(true);
    } 
    else
    {
        m_buttonActiveChannels[i]->setToggleState(false);
    }

    bit >>= 1;
}

Hence using this generates it 16 times and has one method which performs operation based on index i.

Using a similar approach or any other approach, How can I achieve it in my wpf app? 🙂
Please help 🙂

Answer 1

How about something like this?

<ItemsControl ItemsSource="{Binding CollectionOfObjectsThatRepresentYourCheckBox}">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <StackPanel Orientation="Horizontal"
                        IsItemsHost="True" />
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <Checkbox Content="{Binding DisplayText }" Checked="{Binding Checked}" />
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

you would need to populate your collection on objects on load or when a command was executed, then you could react to items being checked in the model that you create for it..

public class CheckBoxClass
{
 public int Index {get; set;}
 public string DisplayText {get; set}
 private bool _checked;
 public bool Checked 
 {
   get { return _checked;}
   set {
        _checked = value
        doSomethingWhenChecked();
       }
}

ObservableCollection<CheckBoxClass> CollectionOfObjectsThatRepresentYourCheckBox = SomeMethodThatPopulatesIt();

this is a much cleaner way to do this and instead of generating the controls you will be just binding to a list of your objects that will be represented by a check box.