Each control has a property DataBindings which is a list of System.Windows.Forms.Binding objects. The Add()-method has some overloads which enables you easily binding to the property of an object:

textBox.DataBindings.Add( "Text", dataObj, "MyProperty" );

Note, that binding basically means subscribing to each others changeevent. The code above subscribes to changeevent of dataObj.MyProperty and adapts textBox.Text when it changes. And vice versa it subscribes to textBox.TextChanged and adapts dataObj.MyPropery when it changes.