Question

I have my custom control named “FileSelectDialog” with Dependency Property:

    public static readonly DependencyProperty FilePathProperty =
         DependencyProperty.Register("FilePath", typeof(string), typeof(FileSelectDialog));

    public string FilePath
    {
        get { return (string)GetValue(FilePathProperty); }
        set { SetValue(FilePathProperty, value); }
    }

Then I’m trying to bind to this dependency property like this:

    <controls:FileSelectDialog FilePath="{Binding FolderName}"/>

But nothing happing, no initial text shown in my control, no updated text’s saving to ‘FolderName’ property! I got such error in Output window:

    System.Windows.Data Error: 40 : BindingExpression path error: 'FolderName' property not found on 'object' ''FileSelectDialog' (Name='FolderSelector')'. BindingExpression:Path=FolderName; DataItem='FileSelectDialog' (Name='FolderSelector'); target element is 'FileSelectDialog' (Name='FolderSelector'); target property is 'FilePath' (type 'String')

So, as far as I understand, control try to find property ‘FolderName on itself, while it must look for it in parents control DataContext. For example, when I use simple textbox:

    <TextBox Text="{Binding Path=FolderName}"/>

All is working fine.

Answer 1

Seems a basic DataContext issue to me
How did you set the DataContext of your FileSelectDialog Control ? seems you set the dataContext in code as ‘Me’/’this’ or in xaml with ‘RelativeSource Self’ or something like this.