CODEWITHSUNDEEP
windows-phone-7mvvm-light
Declan
Declan

Reputation: 539

How do I use ToggleSwitch with MVVM Light in WP7?

I am trying to use a ToggleSwitch with MVVM Light in a Wp7 app.

In the view I have:

<toolkit:ToggleSwitch x:Name="toggleAccuracy" 
  Content="{Binding AccuracyText, Mode=TwoWay}"  
  IsChecked="{Binding AccuracyHigh, Mode=TwoWay}"
  IsEnabled="True" 
  Header="Accuracy" 
  Margin="8,0" 
  Height="140" 
  VerticalAlignment="Top"  >

The ViewModel contains:

private bool _AccuracyHigh = true;
public bool AccuracyHigh
{
    get
    {
        return _AccuracyHigh;
    }
    set 
    {
        _AccuracyHigh = value;
    }
}

private string _AccuracyText = "High";
public string AccuracyText
{
    get
    {
        return _AccuracyText;
    }
    set
    {
        _AccuracyText = value;
    }
}

AccuracyText and AccuracyHigh fire to get the appropriate values.

My difficulty is trying to trap the "state changed" event; Checked and Unchecked. If I bind these with something like: Checked="{Binding Path=AccuracyChanged}" I get a runtime error telling me the markup is wrong.

I also unsuccessfully tried a trigger:

    <i:Interaction.Triggers>
        <i:EventTrigger EventName="Checked">
            <GalaSoft_MvvmLight_Command:EventToCommand Command="{Binding AccuracyChanged}"/>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</toolkit:ToggleSwitch>

I could use RadioButton which work just fine with 

<RadioButton Content="Up"  
             x:Name="radioButton1" 
             GroupName="UpDown" 
             Width="119" />
<RadioButton IsChecked="{Binding UpDown, Mode=TwoWay}" 
             Content="Down" 
             x:Name="radioButton2" 
             GroupName="UpDown" />

public bool UpDown
{
    get
    {
        bool ud = settings.UpDown.ToLower() == "u" ? true : false;
        return ud;
    }
    set
    {
        settings.UpDown = value == true ? "U" : "D";
        settings.Save();
    }
}

but a ToggleSwitch looks better (IMHO)

Any suggestions appreciated.

Upvotes: 4

Views: 2282

Answers (1)

IsolatedStorage
IsolatedStorage

Reputation: 1215

I believe the problem with your markup may be that the IsChecked Property of the ToggleButton can be three states; null,trueorfalse.You are binding it to a boolean but might want to try making it a System.Nullable<Boolean> (bool?) to allow for the three states. I believe this is still necessary even if you set IsThreeState = false;

Upvotes: 5

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