Question

I need twoway binding configClass.RaMsize to numericUpDown.

BindField(this.upDownRamSize, "Value", configClass, "RaMsize");//all right

this.upDownRamSize.Value = 1213;// configClass.RaMsize - not change - it's bad!

Method:

public static void BindField(Control control, string propertyName,
               object dataSource, string dataMember)
        {
            Binding bd;

            for (int index = control.DataBindings.Count - 1; (index == 0); index--)
            {
                bd = control.DataBindings[index];
                if (bd.PropertyName == propertyName)
                    control.DataBindings.Remove(bd);
            }
            control.DataBindings.Add(propertyName, dataSource, dataMember);
        }

Answer 1

I assumed that ConfigClass looks like:

public class ConfigClass
{
    public decimal RaMsize { get; set; }
}

So change
control.DataBindings.Add(propertyName, dataSource, dataMember);
to:

control.DataBindings.Add(propertyName, dataSource, dataMember, false, DataSourceUpdateMode.OnPropertyChanged);

Test:

BindField(this.upDownRamSize, "Value", configClass, "RaMsize");

this.upDownRamSize.Value = 1213;// configClass.RaMsize will also have 1213