Hi all,

I have a dataset, containing 3 tables:

ParentTable (Primary Key = ParentID)
ChildTable1 (Primary Key = Child1ID
ChildTable2 (Primary key = Child2ID

A relation (named Relation1) exists between ParentTable and ChildTable1
A relation (named Relation2) exist between ParentTable and ChildTable2

I have a form containing 3 Bindingsource instances:

BindingSource1 (DataSource = dataSet, DataMember = ParentTable)
BindingSource2 (DataSource = BindingSource1, DataMember = "Relation1")
BindingSource3 (DataSource = BindingSource1, DataMember = "Relation2")

The forms contains several textbox controls, all of them bound to BindingSource1.

The form contains 2 DataGridView controls

DataGridView1 (DataSource = BindingSource2)
DataGridView2 (DataSource = BindingSource3)

I have overriden the AddingNew event of all the BindingSources in order to add some custom initialization when a row is added.

When I open an existing row from the ParentTable, all related rows from ChildTable1 and ChildTable2 (if any) are correctly displayed in the DataGridView control. I am able to change/add/remove rows from the GridView controls as expected.

When I add a new row to the ParentTable (by calling BindingSource1.AddNew), I get the following 'behavior'

When I enter some rows in DataGridView1 (ChildTable1) and then try to add some rows to DataGridView2, the foreign key column contains null values. And I get an error as soon as I stop editing the DataGridView (saying that the field can't be null)

When I fist enter some rows in DataGridView2 (ChildTable2) and then in DataGridView1 (ChildTable1) it all works perfectly!!

I tried to work around the problem set the value of the foreign key field myself when it was null, but this causes the new rows simply to dissapear from the DataGridView

Here's some sample code:

public class Form1 : Form {

private BindingSource BindingSource1;

private BindingSource BindingSource2;

private BindingSource BindingSource3;

public Form1(DataSet ds) {

InitializeComponent();

BindingSource1 = new BindingSource();

BindingSource2 = new BindingSource();

BindingSource3 = new BindingSource();

BindingSource1.DataSource = ds;

BindingSuorce2.DataMember = "ParentTable"

BindingSource2.DataSource = BindingSource1;

BindingSource2.DataMember = "Relation1";

BindingSource3.DataSource = BindingSource1;

BindingSource3.DataMember = "Relation2";

DataGridView1.DataSource = BindingSource2;

DataGridView2.DataSource = BindingSource3;

BindingSource1.AddingNew += new AddingNewEventHandler(BindingSource1_AddingNew);

BindingSource2.AddingNew += new AddingNewEventHandler(BindingSource2_AddingNew);

BindingSource3.AddingNew += new AddingNewEventHandler(BindingSource3_AddingNew);

}

void BindingSource1_AddingNew(object sender, AddingNewEventArgs e) {

//get the bindingsource

BindingSource bs = (BindingSource)sender;

//get the underlying dataview

System.Data.DataView view = (System.Data.DataView)bs.List;

//get a new row

DataRowView row = view.AddNew();

//do some initalization of the new row

//....

e.NewObject = row;

}

void BindingSource2_AddingNew(object sender, AddingNewEventArgs e) {

BindingSource1.EndEdit();

//get the bindingsource

BindingSource bs = (BindingSource)sender;

//get the underlying dataview

System.Data.DataView view = (System.Data.DataView)bs.List;

//get a new row

DataRowView row = view.AddNew();

//here, the foreing key has been correctly set to the id of the

//ParentTable

//do some initalization of the new row

//....

e.NewObject = row;

}

void BindingSource3_AddingNew(object sender, AddingNewEventArgs e) {

BindingSource1.EndEdit();

//get the bindingsource

BindingSource bs = (BindingSource)sender;

//get the underlying dataview

System.Data.DataView view = (System.Data.DataView)bs.List;

//get a new row

DataRowView row = view.AddNew();

//If records have been added to BindingSource2 (by adding rows

//to DataGridView1, the foreing key field of the row contains a DBNull value

//(The problem does not occur when editing an existing ParentTable row)

//do some initalization of the new row

//....

e.NewObject = row;

}

}

Any ideas will be greatlyl appreciated.

Regards,

I have got a DataGridView which is bound to my custom business object. When no value is entered into a column when a new row is added it sends a Null value down to my string property in the business layer. Therefore when I call the stored procedure to save the data it fails.

I can check in the code for the value being null and assigning it an empty string but I would rather do it using the binding properties. I have tried setting the following properties but this doesnt work:

column.DefaultCellStyle.DataSourceNullValue = DBNull.Value;

column.DefaultCellStyle.NullValue = "";

To summarise, all I want to do is that if no string is entered in a column then it passes a space to the bound business layer instead of a null.

Regards,

Richard.

I have a listbox that's bound to a relationship between a table and a dataview.

How do I 'refresh' the listbox when a new record is inserted into the tables 'viewed' by the view

If the whole application is shut down and restarted, the listbox shows the new data, so I know the database is right.

Hi,

I have a VS2005 project that contains a main windows form and various user controls that I want to place on the main form.

How can I add the user controls to the toolbox

The only examples I can find describe creating the user control as a separate project and adding it to the solution. You can then add the control by selecting its .dll. This doesn't work for me because both the main form and user control access a common interface. I then get multiply defined reference errors, presumably because the symbol is defined in the .dll and also in the main form project.

I'd be very grateful for any help

Phill

Hi,

Here is a problem I'm facing: People want to have several versions of a same application at the same time on the same PC: e.g.: Production version and Q&A version.

So I made several deployments of this application where only the application.config file and the Application name differs (sometimes even the version also differs).

The problem is that if you install first the QA version and just after the PROD version, the PROD version overwrites the QA version.

Is there a way to make them available at the same time

I think this problem comes from the appref-ms shortcut where the AssemblyIdentity, Culture, PublicToken and ProcessorArchitecture are exactly the same for both applications... but I don't know how to modify them...

Any help would be greatly appreciated,

Regards,

Laurent

hi,

In my application...I have a datagrid on my form.My datagrid contains a textcoxcolumn & a comboboxcolumn…so I want to know how I can put values in textbox column on form load event….

Say I have 5 rows & I want those 5 rows to have 5 strings in the textbox column. Strings are(string1, string2, string3, string4 & string5).

So how I can put it in that datagrids 1^st textboxcolumn (in form load event ).

Thanks,

Vinay

Hi guys,

I have a foreach loop that creates runtime textboxes. The textboxes getting filled from the database.

My code;

foreach (DataRow dr in scoretable.Rows)

scorebox = new TextBox();

scorebox.Name = "scorebox" + i;

scorebox.Location = new Point(x, y);