[RESOLVED] DateTimePicker - custom DataBinding to return DBNull.Value

[LuckyLuke82]

Hi,

I've created a custom DateTimePicker which shows empty If Databinded to DBNull.Value, with a trick of setting CustomFormat. Only problem I'm facing is to return DBNull.Value from DateTimePicker when I save changes to DB. Here is my code:

  public object MyValue
        {  
            //Binding with DBNull
            get
            {
                if (this.Format == DateTimePickerFormat.Custom)
                {
                     return DBNull.Value;
                }  
                else
                {
                    return this.Value;
                }                  
               
            }
            set
            {
                if (value == DBNull.Value)
                {
                    this.Format = DateTimePickerFormat.Custom;
                    this.CustomFormat = " ";
                    //DateTime? dt =DBNull.Value; //error here
                    //Value = (DateTime)dt;
                }
                else
                {
                    this.Format = DateTimePickerFormat.Short;
                    this.Value = (DateTime)value;
                }
            }
        }

I bind to DateTimePicker simply as this: DTP.DataBindings.Add("MyValue", dt, "SOME_COLUMN");

Error I'm facing is "Nullable object must have a value?".

Can somebody help me If there is any solution to this ? Currently I just manually set DB.NULL in place where stored procedure is executed, and I want to get rid of these lines.

[LuckyLuke82]

Solved.

Only problem was that I was referencing "DTP.Value" in my stored procedure, but I should reference "DTP.MyValue" instead. Saving to DB now works, with DBNull.Value At least someone could benefit a little in future when dealing with DateTimePicker like this

[jmcilhinney]

Don't use a name like MyValue for a property. Something like BindableValue would be more appropriate.

[LuckyLuke82]

Hi jm, thanks for that. It's not MyValue in real actually, It's some word in my language so I'm pretty sure CLR won't mix It with something else