dt.Columns.Add("One");

dt.Columns.Add("Two");

dt.Columns.Add("Three");

dt.Rows.Add(new string[] { "1", "2", "3" });

dt.Rows.Add(new string[] { "4", "5", "6" });

dt.Rows.Add(new string[] { "7", "8", "9" });

dataGridView1.DataSource = dt;

dt.ColumnChanging += new DataColumnChangeEventHandler(dt_ColumnChanging);
extendedTextBox1.DataBindings.Add("Value", dt, "One");
extendedTextBox2.DataBindings.Add("Text", dt, "Two");
extendedTextBox3.DataBindings.Add("Text", dt, "Three");

When extendedTextBox2 focused and i move the tab to extendedTextBox3 the event ColumnChanging not raised, But when extendedTextBox1focused and i move the tab to extendedTextBox2 the event ColumnChanging raised.

This occurs because i set the extendedTextBox1.DataBindings to property [Value], why this occurs and what is the solution for this issue?

Thanks,
khalil

Hi khalil,

I tested the code and found that the value in the One column is being set, though the old value is equal to the new value. We can create our own DataTable to ignore this case. This is the code snippet:
public class MyDataTable : DataTable

{

protected override void OnColumnChanging(DataColumnChangeEventArgs e)

{

if (e.Row[e.Column] != e.ProposedValue)

//Raise the event only when the old value not equal to the new value.

base.OnColumnChanging(e);

else

//If equal, recover.

e.Row.RejectChanges();

}

}

 public class ExtendedTextBox : TextBox,INotifyPropertyChanged
    {
        private string sVal;
        public string Value
        {
            get { return sVal; }
            set {
                if (sVal != value)
                {
                    sVal = value;
                    OnPropertyChanged("Value");
                }
                
            }
        }

    
        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        private void OnPropertyChanged(string properyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(properyName));
        }
        

        #endregion
    }

public class ExtendedTextBox : TextBox
{
private string sVal;
public string Value
{
get { return sVal; }
set { sVal = value; }
}
}

Hello,
Anybody there ?

Hi khalil,

I tested the code and found that the value in the One column is being set, though the old value is equal to the new value. We can create our own DataTable to ignore this case. This is the code snippet:
public class MyDataTable : DataTable

{

protected override void OnColumnChanging(DataColumnChangeEventArgs e)

{

if (e.Row[e.Column] != e.ProposedValue)

//Raise the event only when the old value not equal to the new value.

base.OnColumnChanging(e);

else

//If equal, recover.

e.Row.RejectChanges();

}

}

Thnx,

Iknow this bypass, but i think thatit is not the solution because :

1. e.Row.RejectChanges(); reject the changesfor all the columns in the row.
2. I need to know why thisissue occur when i set the binding to[Value] property, what is the diff between [Text] property and value property?

Thnx,

Iknow this bypass, but i think thatit is not the solution because :

1. e.Row.RejectChanges(); reject the changesfor all the columns in the row.
2. I need to know why thisissue occur when i set the binding to[Value] property, what is the diff between [Text] property and value property?

Another thing as you suggest this is bug in the datatable object or the wayof the databinding working with custom property,
i thought that this case is bug, what is your opinion about this case ?

 public class ExtendedTextBox : TextBox,INotifyPropertyChanged
    {
        private string sVal;
        public string Value
        {
            get { return sVal; }
            set {
                if (sVal != value)
                {
                    sVal = value;
                    OnPropertyChanged("Value");
                }
                
            }
        }

    
        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        private void OnPropertyChanged(string properyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(properyName));
        }
        

        #endregion
    }