Question

I am new to WPF and C#, I try to implement the following feature, but failed after a lot of attempts. Can anyone help me out?

I have an image control:

<Image Grid.Row="1" x:Name="ImageEditor"  Stretch="Fill" StretchDirection="Both"/>

I want to bind the source of this image control to a static property of another class (ImageHandler)

class ImageHandler
{
    public static BitmapImage ImageToDisplay { get; set; }

    public ImageHandler(){}

    .... //other codes
}

So whenever I do something in the ImageHandler class, and update the ImageToDisplay property, my image control will display the new image.

I have try several methods, but none of them achieved this goal. The following shows one of my failed attempts.

<Window.Resources>
    <local:ImageHandler x:Key="ImageHandler"></local:ImageHandler>
</Window.Resources>

<Image Grid.Row="1" x:Name="ImageEditor" Stretch="Fill" StretchDirection="Both" 
    Source="{Binding Source={StaticResource ResourceKey=ImageHandler},
    Path=ImageToDisplay,Mode=TwoWay}">
</Image>

Answer 1

You have to implement either INotifyPropertyChanged in ImageHandler

For dependency property :

class ImageHandler : INotifyPropertyChanged
{
    private BitmapImage imageToDisplay;
    public BitmapImage ImageToDisplay
    {
        get { return imageToDisplay; }
        set
        {
            if (imageToDisplay != value)
            {
                imageToDisplay = value;
                OnPropertyChanged("ImageToDisplay");
            }
        }
    }

    public ImageHandler() { }

    // .... Other codes

    #region INotifyPropertyChanged implementation
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }
    #endregion
}

However, to implement it, I had to remove the static attribute.