How to pass parameters to usercontrol's viewmodel through window's xaml?

Question

How to pass parameters to usercontrol's viewmodel through window's xaml? I am using MVVM pattern. I have tried creating a dependency property as below. But passing it in constructoe of viewmodel throws "nonstatic properties cannot be field initializers" exception. xaml.cs of usercontrol

public partial class SomeView : UserControl
{   
    SomeViewModel vm = new SomeViewModel(ForeColor);

    public SomeView()
    {
        InitializeComponent();
        this.DataContext = vm;
    }

    public Color ForeColor
    {
        get { return (Color)this.GetValue(ForeColorProperty); }
        set { this.SetValue(ForeColorProperty, value); }
    }

    public static readonly DependencyProperty ForeColorProperty = DependencyProperty.Register("ForeColor", typeof(Color), typeof(SomeView ));
}

and this is how I am calling the user control

 <local:SomeView ForeColor="{Binding Foreground}"/>

Foreground is a property of type System.Drawing.Color

Rohit Vats Rohit Vats · Accepted Answer · 2014-02-10T18:27:07

As the error stated you cannot refer instance fields from field initializers.

Move the initialization logic to constructor instead:

SomeViewModel vm;

public SomeView()
{
    InitializeComponent();
    vm = new SomeViewModel(ForeColor);
    this.DataContext = vm;
}

How to pass parameters to usercontrol's viewmodel through window's xaml?

2 Answers