Fun With DataSets

Data in a DataRow has several different versions. First, there's the original version. Then, when it's being edited (either in a UI control, like a TextBox or programmatically), it has a Proposed version and once it's done being edited, that becomes the Current version. Sometimes when entering data in a UI control, the row is left in the Proposed state and the Edit needs to be ended programmatically. This doesn't always happen and I'm not entirely sure why it's seemingly random (maybe it's an ADO.NET bug).
Say, for example, that you have made only one change in your entire DataSet and, for that unexplained reason, the DataRow is still in its Proposed version. If you check the DataSet.HasChanges() method, it will return a false. If you do a DataSet.GetChanges() you will not get anything returned. That's not a good thing. UPDATE: See my most recent post, DataBinding DataSets: Directly vs BindingSource ,explaining why this may not apply if you use BindingSource to DataBind your Controls.
But there's a solution to this little gotcha: here's a method I *always* call before I attempt to check for .HasChanges() or do a .GetChanges() before saving data:

protected virtual void CommitProposedChanges(DataSet ds)
{
    if (ds == null)
        return;
 
    for (int nTable = 0; nTable < ds.Tables.Count; nTable++)
    {
        for (int nRow = 0; nRow < ds.Tables[nTable].Rows.Count; nRow++)
        {
            if (ds.Tables[nTable].Rows[nRow].HasVersion(DataRowVersion.Proposed))
            {
                ds.Tables[nTable].Rows[nRow].EndEdit();
            }
        }
    }
}

UPDATE: If you read the comments below, you’ll see that that there was some talk about the speed of for vs foreach. It turns out that I have had a misconception for many, many, *many* years that for was faster than foreach. Perhaps it used to be back in the .NET 1.1 days, but it certainly hasn’t been the case since them. See my recent blog post about this here: http://geek-goddess-bonnie.blogspot.com/2016/02/compare-speed-of-for-vs-foreach.html

Consequently, I’m going to add another method to this post, using foreach instead of for:

protected virtual void CommitProposedChanges(DataSet ds)
{
    if (ds == null)
        return;
 
    foreach (DataTable dt in this.dsGlobal.Tables)
        foreach (DataRow row in dt.Rows)
        {
            if (row.HasVersion(DataRowVersion.Proposed))
                row.EndEdit();
        }

}