复选框WPF MVVM

Question

Hi all i have problem in this code, please help me..

I have view

<StackPanel Orientation="Horizontal" Margin="3">
            <Label Content="Audit Type" MinWidth="100"/>
            <Label Content=":"/>
            <StackPanel Orientation="Vertical">
                <ListBox ItemsSource="{Binding Items}" Margin="3" SelectionMode="Extended" MinWidth="180">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal">
                                <CheckBox Name="check" Content="{Binding Value}" IsChecked="{Binding IsChecked, Mode=TwoWay}" Margin="3" VerticalAlignment="Center"/>
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </StackPanel>
        </StackPanel>

and for View model

private List<AuditTypeExport> _items;
private List<string> _value;
private bool _isChecked;

public bool IsChecked
    {
        get { return _isChecked; }
        set
        {
            _isChecked = value;
            OnPropertyChanged("IsChecked");
        }
    }

    public List<AuditTypeExport> Items
    {
        get { return _items; }
    }

    public List<string> Value
    {
        get { return _value; }
        set 
        { 
            _value = value;
            OnPropertyChanged("Value");
        }
    }

And ViewModel Constractor

_items = _model.GetAuditType();
_value = _model.GetAuditType().Select(item => item.Name).ToList();

For your information

public class AuditTypeExport
{
    private int _id;
    private string _name;

    [DataMember]
    public int Id { get; set; }

    [DataMember]
    public string Name { get; set; }

The result : checkbox appeares, but the content doesn't and I don't have a clue why.

Question Number 2 : I want to get the value back, how can I do that?

Thank you

Answer 1

It is unclear how you are using your ViewModel. Is that bound to the form? Or each item in the ListBox?

It looks like your ListBox is bound to the Items collection of your VM, so the ItemTemplate will be used with a AuditTypeExport as the data context. You are binding to "Value" and "IsChecked" properties which do not exist on the AuditTypeExport class.

Answer 2

What you are trying to do here is bind a property of type List<String> Value to CheckBox 's Content property which is of type Object .

To simplify, you are assigning a collection of strings to a string. Which is not a good thing. And that is why it does not work.

Try using ItemsControl to show Value property or use an IValueConverter to convert List<String> to comma separated string.