CODEWITHSUNDEEP
c#winformsbinding
John Twigg
John Twigg

Reputation: 7591

custom binding .net forms

Is there any way to get custom binding behavior in .net win forms?

Example, I'm connecting my control to a BindingSource object and adding a binding like

this.slider.DataBindings.Add(new System.Windows.Forms.Binding("Enabled", this.bindingSourceModel, "FloatProperty  > 0.5f", true));

There's no way the above will work but I like it to be enabled if dataSource.FloatProperty becomes greater than 0.5f.

Is there any way to do this?

Upvotes: 2

Views: 709

Answers (1)

Fernando Espinosa
Fernando Espinosa

Reputation: 4855

I understand what you want to do, so I've slightly modified your situation for the sake of demonstration: the UI setup is obvious, there is a TrackBar and a Button, and the problem here is to bind the Enabled property of button to the boolean value of the expression trackBar.Value > 50.

The idea is to turn the main form into something like a ViewModel (as in MVVM). Observe that I am implementing INotifyPropertyChanged.

enter image description here enter image description here

public partial class ManiacalBindingForm : Form, INotifyPropertyChanged {

    public ManiacalBindingForm() {
        InitializeComponent();

        this.button.DataBindings.Add("Enabled", this, "ManiacalThreshold", true, DataSourceUpdateMode.OnPropertyChanged);

        this.trackBar.ValueChanged += (s, e) => {
            this.Text = string.Format("ManiacalBindingForm: {0}", this.trackBar.Value);
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("ManiacalThreshold"));
        };
    }

    public bool ManiacalThreshold {
        get { return this.trackBar.Value > 50; }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    ...
}

Now, this is my personal observation: While there is a non-trivial interpretation of your goal, your goal is a bit maniacal. You have to ponder why exactly you want to achieve this through data-binding. Binding is mostly aimed for automatic, bi-directional, sync'ing of property values. Doing this type of UI update via binding directly to the "model" is even more maniacal. But you got credit for being maniacal, though! ;-)

Upvotes: 1

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