C# - Binding TextBox to an integer

c#, data-binding, winforms

Solution

It would need to be a public property of an instance; in this case, the "this" would suffice:

public int Unit {get;set;}
private void Form1_Load(object sender, EventArgs e)
{
    textBox1.DataBindings.Add("Text", this, "Unit");
}

For two-way notification, you'll need either `UnitChanged` or `INotifyPropertyChanged`:

private int unit;
public event EventHandler UnitChanged; // or via the "Events" list
public int Unit {
    get {return unit;}
    set {
        if(value!=unit) {
            unit = value;
            EventHandler handler = UnitChanged;
            if(handler!=null) handler(this,EventArgs.Empty);
        }
    }
}

If you don't want it on the public API, you could wrap it in a hidden type somewhere:

class UnitWrapper {
    public int Unit {get;set;}
}
private UnitWrapper unit = new UnitWrapper();
private void Form1_Load(object sender, EventArgs e)
{
    textBox1.DataBindings.Add("Text", unit, "Unit");
}

For info, the "events list" stuff goes something like:

    private static readonly object UnitChangedKey = new object();
    public event EventHandler UnitChanged
    {
        add {Events.AddHandler(UnitChangedKey, value);}
        remove {Events.AddHandler(UnitChangedKey, value);}
    }
    ...
    EventHandler handler = (EventHandler)Events[UnitChangedKey];
    if (handler != null) handler(this, EventArgs.Empty);

Problem

How to bind a TextBox to an integer? For example, binding unit to textBox1. ``` public partial class Form1 : Form { int unit; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { textBox1.DataBindings.Add("Text", unit, "???"); } ```

Original source