Button enable and disable on text changed event

Question

I am wondering how I can set a button to disable if there is no text inside a text box, but when there is re enable it? Would I put it into a text changed event?

Answer 1

You can do it in a more structured way using data binding and the little helper from here Exchange UserControls on a Form with data-binding

static void Bind(Control target, string targetProperty, object source, string sourceProperty, Func expression)
{
    var binding = new Binding(targetProperty, source, sourceProperty, true, DataSourceUpdateMode.Never);
    binding.Format += (sender, e) => e.Value = expression(e.Value);
    target.DataBindings.Add(binding);
}

Note that this is reusable piece of code that you can use in many scenarios. For your particular case, all you need is (after copying the code above) to put the following line in your form load event:

Bind(button1, "Enabled", textBox1, "Text", value => !string.IsNullOrEmpty((string)value));