Bound DataGridView not updating data source
- by Max Yaffe
I'm trying to bind a table of structures to a DataGridView. Loading and viewing the table is working fine but I can't edit a value and get it stored back into the table. Here's what I'm doing.
I have a "primitive" data type, Real defined by
public struct MyReal:IMyPrimative
{
public Double m_Real;
//...
public MyReal(String val)
{
m_Real = default(Double);
Init(val);
}
//...
}
It gets used in a structure:
public struct MyReal_Record : IMyRecord
{
public MyReal Freq { get; set;}
MyReal_Record(String[] vals)
{
Init(vals);
}
}
And the structure is used to define a table using a generic Binding List
public class MyTable<S> : BindingList<S> where S: struct, IMyRecord
{
public Type typeofS;
public MyTable()
{
typeofS = typeof(S);
// ...
}
This table is used as a binding source for a grid, dynamically.
private void miLoadFile_Click(object sender, EventArgs e)
{
MyModel.Table<Real_Record> RTable = new MyModel.Table<Real_Record>();
//... Table initialized here
//set up grid with virtual mode
dataGridView1.DataSource = RTable;
}
All of this works fine and I can create RTable, initialize it and display it in a grid. The grid allows editing and has events set for CellParsing and CellFormatting which look like:
private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
if (e.DesiredType != typeof(String))
return;
e.Value = e.Value.ToString();
}
private void dataGridView1_CellParsing(object sender, DataGridViewCellParsingEventArgs e)
{
if (e.DesiredType != typeof(MyReal))
return;
e.Value = new MyReal(e.Value.ToString());
e.ParsingApplied = true;
this.dataGridView1.UpdateCellValue(e.ColumnIndex, e.RowIndex);
}
When I edit a value in a cell, I can change the text. On leaving the cell, CellParsing fires and the event handler is called. Everything seems to be correct going into the CellParsing handler. e.DesiredType is MyReal. e.Value is a string with the new value. After the new MyReal is created from the string, e.Value is set correctly. RowIndex and ColumnIndex are correct. ReadOnly is set false.
However, when I leave the cell, the system restores the original value to the cell. I thought the UpdateCellValue would replace the value in the dataSource but I seem to be missing something.
What did I miss?
Thanks,
Max
