How to...

  • Thread starter Thread starter Jacek Jurkowski
  • Start date Start date
J

Jacek Jurkowski

.... bind nullable control property to nullable value?
The simpliest scenario:

public class a
{
Nullable<DateTime> myDate = null;

public Nullable<DateTime> MyDate
{
get{return myDate;}
set{myDate = value;}
}
}

public class MyControl : UserControl
{
Nullable<DateTime> date = null;

public Nullable<DateTime> Date
{
get{return date;}
set{date = value;}
}
}

public class MyForm : Form
{
a class_a = new a();
MyControl my_control = new MyControl();

protected override void OnLoad(EventArgs e)
{
this.Controls.Add(my_control);
// Next line causes the error.
// "Cannot format the value to the desired type".
my_control.DataBindings.Add("Date",class_a,"MyDate");
}
}

What to do to allow such binding in the simpliest way?
 
... bind nullable control property to nullable value?
The simpliest scenario:

public class a
{
    Nullable<DateTime> myDate = null;

    public Nullable<DateTime> MyDate
    {
        get{return myDate;}
        set{myDate = value;}
    }

}

public class MyControl : UserControl
{
    Nullable<DateTime> date = null;

    public Nullable<DateTime> Date
    {
        get{return date;}
        set{date = value;}
    }

}

public class MyForm : Form
{
        a class_a = new a();
        MyControl my_control = new MyControl();

        protected override void OnLoad(EventArgs e)
        {
            this.Controls.Add(my_control);
            // Next line causes the error.
            // "Cannot format the value to the desired type".
            my_control.DataBindings.Add("Date",class_a,"MyDate");
        }

}

What to do to allow such binding in the simpliest way?
Click to expand...

I'm not 100% sure that it is possible, but try playing with
Binding.NullValue and Binding.DataSourceNullValue (the latter in
particular defaults to DBNull.Value rather than null, which may be the
cause of your troubles).
 
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