c# - Data binding for TextBox

Question

I have a basic property that stores an object of type Fruit:

Fruit food;
public Fruit Food
{
    get {return this.food;}
    set
    {
        this.food= value;
        this.RefreshDataBindings();
    }
}

public void RefreshDataBindings()
{
    this.textBox.DataBindings.Clear();
    this.textBox.DataBindings.Add("Text", this.Food, "Name");
}

So I set this.Food outside the form and then it shows up in the UI.

If I modify this.Food, it updates correctly. If I modify the UI programmatically like:

this.textBox.Text = "NewFruit", it doesn't update this.Food.

Why could this be? I also implemented INotifyPropertyChanged for Fruit.Name, but still the same.

Answer 1

I Recommend you implement INotifyPropertyChanged and change your databinding code to this:

this.textBox.DataBindings.Add("Text",
                                this.Food,
                                "Name",
                                false,
                                DataSourceUpdateMode.OnPropertyChanged);

That'll fix it.

Note that the default DataSourceUpdateMode is OnValidation, so if you don't specify OnPropertyChanged, the model object won't be updated until after your validations have occurred.