RadioButton, Binding, Converters

问题

I am working on Visual Studio 2008, and I have a problem with radiobuttons.

I have 3 radioButton :

   <Window.Resources>
      // [...]
   <DataTemplate x:Key="gridViewReadyTemplate">
        <StackPanel>
            <RadioButton GroupName="{Binding IdCommand}" IsChecked="{Binding CommandState, Mode=TwoWay, Converter={StaticResource enumBooleanConverter}, ConverterParameter=ready}" />
        </StackPanel>
    </DataTemplate>

    <DataTemplate x:Key="gridViewReportedTemplate">
        <StackPanel>
            <RadioButton GroupName="{Binding IdCommand}" IsChecked="{Binding CommandState, Mode=TwoWay, Converter={StaticResource enumBooleanConverter}, ConverterParameter=reported}" />
        </StackPanel>
    </DataTemplate>

    <DataTemplate x:Key="gridViewCanceledTemplate">
        <StackPanel>
            <RadioButton GroupName="{Binding IdCommand}" IsChecked="{Binding CommandState, Mode=TwoWay, Converter={StaticResource enumBooleanConverter}, ConverterParameter=canceled}" />
        </StackPanel>
    </DataTemplate>

    // [...]


   <ListView Margin="82,133.32,342.5,0" Name="listView1" ItemsSource="{Binding CurrentTrain.PSCommandCollection, Mode=TwoWay}" Height="111.25" VerticalAlignment="Top">
        <ListView.View>
            <GridView>
                // [...]
                <GridViewColumn Header="Préparé" Width="50" CellTemplate="{StaticResource gridViewReadyTemplate }" />
                <GridViewColumn Header="Reporté" Width="50" CellTemplate="{StaticResource gridViewReportedTemplate }" />
                <GridViewColumn Header="Annulé" Width="50" CellTemplate="{StaticResource gridViewCanceledTemplate }" />
            </GridView>
        </ListView.View>
    </ListView>

The converter :

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
    string param = (string)parameter;
    Enumerators.State state = (Enumerators.State)value;

    switch (param)
    {
        case "ready":
            if (state == Enumerators.State.READY)
                return true;
            return false;
        case "reported":
            if (state == Enumerators.State.REPORTED)
                return true;
            return false;
        case "canceled":
            if (state == Enumerators.State.CANCELED)
                return true;
            return false;
    }
    return false;
}

public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
    string param = (string)parameter;

    if ((bool?)value == true)
    {
        switch (param)
        {
            case "ready":
                return Enumerators.State.READY;
            case "reported":
                return Enumerators.State.REPORTED;
            case "canceled":
                return Enumerators.State.CANCELED;
        }
    }
    return Enumerators.State.NONE;
}

And the property where radiobutton are binding on :

private Enumerators.State commandState;
public Enumerators.State CommandState
{
    get { return commandState; }
    set
    {
        if (commandState != value)
        {
            commandState = value;
            NotifyPropertyChanged("CommandState");
        }
        else
        {
            commandState = Enumerators.State.NONE;
            NotifyPropertyChanged("CommandState");
        }
    }
}

When I click on a radiobutton, the state is changing well. The problem is when I want to uncheck a radiobutton by clicking on it, the state changes, but the radiobutton still checked.

I put breakpoint in my converter, function Convert. For example, if I want to uncheck "ready", the program go in 2 times, for "reported" and "canceled", but not for "ready"...

I really don't understand where is the problem. Can you explain me how to fix it ?

回答1:

This is the problem with RadioButton. It loses its binding once it gets unchecked. To fix this, you can bind RadioButton.Command of Radiobuttons to a command of your ViewModel and send a unique CommandParameter to identify which button has called the command in commandhandler.

<RadioButton Command="{Binding MyCommand}" CommandParameter="Radio1"/>
<RadioButton Command="{Binding MyCommand}" CommandParameter="Radio2"/>
<RadioButton Command="{Binding MyCommand}" CommandParameter="Radio3"/>

and in the command handler you can set the property depending on the command parameter received instead of doing it in converter.

来源：https://stackoverflow.com/questions/23823844/radiobutton-binding-converters

标签

wpf

xaml

binding

converter