CODEWITHSUNDEEP
c#winformsdata-binding
justAuser
justAuser

Reputation: 60

How to bind elements to each other?

I have Control in which I bind my own class Element with "DataBindings". If I change "Width" and "Height", for example, in "E", Control change the same properties as well. But other side it don't work.

this.DataBindings.Add("Width", E, "Width");
this.DataBindings.Add("Height", E, "Height");

What is the best way to fix it? Only by hands, problem that there is many properties? Or exists something like "DataBindings"?

P.S. Element not inherited from any class, he haven't "DataBindings". Thanks!

Upvotes: 0

Views: 138

Answers (4)

stuartd
stuartd

Reputation: 73253

Whan adding your bindings, use one of the overloads which allow you to to set the DataSourceUpdateMode and set it to DataSourceUpdateMode.OnPropertyChanged

Upvotes: 0

LarsTech
LarsTech

Reputation: 81620

I don't think a control will report width and height property changes to the databinding listeners.

Try adding the INotifyPropertyChanged to the control and take over the Width and Height properties yourself.

An example using a Panel control:

public class PanelEx : Panel, INotifyPropertyChanged {
  public event PropertyChangedEventHandler PropertyChanged;

  public new int Width {
    get { return base.Width; }
    set {
      base.Width = value;
      OnPropertyChanged("Width");
    }
  }

  public new int Height {
    get { return base.Height; }
    set {
      base.Height = value;
      OnPropertyChanged("Height");
    }
  }

  private void OnPropertyChanged(string propertyName) {
    if (PropertyChanged != null)
      PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
  }
}

Then change your databinding call to this, where this is your control with the above implementation:

this.DataBindings.Add("Width", E, "Width", false, DataSourceUpdateMode.OnPropertyChanged);
this.DataBindings.Add("Height", E, "Height", false, DataSourceUpdateMode.OnPropertyChanged);

Upvotes: 0

clearpath
clearpath

Reputation: 956

You should implement INotifyPropertyChanged in your class E for every property you want to bind.

Other way around won't work. Control has to have *Changed event for every property that needs to update datasource. For your example, you can try with Size property of the control, because there is a SizeChanged event.

Upvotes: 0

Christoph Fink
Christoph Fink

Reputation: 23103

To get it working both ways the following must be present:

  • Both Proerties are required to be dependency properties or the containing class must implement INotifyPropertyChanged
  • The Mode of the Binding must be TwoWay

EDIT: Just saw you are using WinForms - I'm not shure it works there the same way!

Upvotes: 2

Related Questions