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Datagrid does not update datasource efficientlyI have a Windows form datagrid which is bound to a datatable in a dataset. I want changes that the user performs on the information in the datagrid to be automatically reflected in the the underlying datatable. For the most part this is working. Then sometimes it does not, and I can't figure out why. It seems that if you change a given datagrid row, and then click on a different datagrid row, the change generally gets recorded. If you change a row, and do not click on a different row, the change is generally NOT recorded, no matter how many cells on that datagrid row you altered. I don't understand why this is, and why it is not completely predictable. It also creates a problem for users who might simply make a change and forget the extra step of clicking somewhere else. What is the exact mechanism (event?) which causes the datasource of the datagrid to be updated? Is there any way to force the datasource to update itself? Any help would be appreciated. I doubt if you have given enough information to answer your question. I'll
give my ideas though. Some things have changed between 2003 and 2005, in particular in 2005, you now have the bindingsource which is far easier to use than the currency manager. The currency manager takes a bit more code and you have to pay closer attention to what you are doing with positioning. So it follows that most of what you ask is totally dependent upon how you have set up your datagrid and the datasource. If you have this bound to a bindingsource, then the bindingsource will update as you make changes in the grid. As the bindingsource changes, it updates the underlying datatable. It's up to you to write the code to fire the update from the bindingsource datasource back to the database. If the grid is NOT bound to a bindingsource, then you have even more plumbing to write. And I certainly agree that the tricky part of working with "automatic" updates in the grid can be to ensure that all changes get recorded. I have taken the easier route and not allowed the user to do in-grid edits, but to each his own. The grid edits look much cleaner, use fewer controls, but at the same time, force you to monitor more user events, both in the grid and out. If your question is, why are changes not being reflected back into the database when you make multiple edits in one row of the grid, and the necessary code is written to fire an update otherwise, then you probably have a concurrency issue in your stored procedure. In order to do multiple updates on one row of the grid, every time you fire an update, you must retrieve that newly updated row of data back to your datagrid datasource, otherwise your next update in that row will have a concurrency issue (the row in the grid no longer matches the row in the datatable or no longer matches the row in the database). <bida***@yahoo.com> wrote in message Show quote news:1171488907.114832.36990@h3g2000cwc.googlegroups.com... > Hello all, > > I have a Windows form datagrid which is bound to a datatable in a > dataset. I want changes that the user performs on the information in > the datagrid to be automatically reflected in the the underlying > datatable. > > For the most part this is working. Then sometimes it does not, and I > can't figure out why. It seems that if you change a given datagrid > row, and then click on a different datagrid row, the change generally > gets recorded. If you change a row, and do not click on a different > row, the change is generally NOT recorded, no matter how many cells on > that datagrid row you altered. I don't understand why this is, and > why it is not completely predictable. It also creates a problem for > users who might simply make a change and forget the extra step of > clicking somewhere else. > > What is the exact mechanism (event?) which causes the datasource of > the datagrid to be updated? Is there any way to force the datasource > to update itself? Any help would be appreciated. >
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On Feb 15, 12:26 am, "Earl" <briks...@newsgroups.nospam> wrote: Hi Earl. Thanks for responding.> I doubt if you have given enough information to answer your question. I'll > give my ideas though. > > Some things have changed between 2003 and 2005, in particular in 2005, you > now have the bindingsource which is far easier to use than the currency > manager. The currency manager takes a bit more code and you have to pay > closer attention to what you are doing with positioning. > > So it follows that most of what you ask is totally dependent upon how you > have set up your datagrid and the datasource. If you have this bound to a > bindingsource, then the bindingsource will update as you make changes in the > grid. As the bindingsource changes, it updates the underlying datatable. > It's up to you to write the code to fire the update from the bindingsource > datasource back to the database. > > If the grid is NOT bound to a bindingsource, then you have even more > plumbing to write. And I certainly agree that the tricky part of working > with "automatic" updates in the grid can be to ensure that all changes get > recorded. I have taken the easier route and not allowed the user to do > in-grid edits, but to each his own. The grid edits look much cleaner, use > fewer controls, but at the same time, force you to monitor more user events, > both in the grid and out. > > If your question is, why are changes not being reflected back into the > database when you make multiple edits in one row of the grid, and the > necessary code is written to fire an update otherwise, then you probably > have a concurrency issue in your stored procedure. In order to do multiple > updates on one row of the grid, every time you fire an update, you must > retrieve that newly updated row of data back to your datagrid datasource, > otherwise your next update in that row will have a concurrency issue (the > row in the grid no longer matches the row in the datatable or no longer > matches the row in the database). > > <bida***@yahoo.com> wrote in message > > news:1171488907.114832.36990@h3g2000cwc.googlegroups.com... > > > > > Hello all, > > > I have a Windows form datagrid which is bound to a datatable in a > > dataset. I want changes that the user performs on the information in > > the datagrid to be automatically reflected in the the underlying > > datatable. > > > For the most part this is working. Then sometimes it does not, and I > > can't figure out why. It seems that if you change a given datagrid > > row, and then click on a different datagrid row, the change generally > > gets recorded. If you change a row, and do not click on a different > > row, the change is generally NOT recorded, no matter how many cells on > > that datagrid row you altered. I don't understand why this is, and > > why it is not completely predictable. It also creates a problem for > > users who might simply make a change and forget the extra step of > > clicking somewhere else. > > > What is the exact mechanism (event?) which causes the datasource of > > the datagrid to be updated? Is there any way to force the datasource > > to update itself? Any help would be appreciated.- Hide quoted text - > > - Show quoted text - I know my original question was vague; I wasn't sure what kind of information was needed. I am using VS2005. I don't have an underlying database. I am using a dataset to compile and store in- session data from the datagrid. I didn't create a bindingsource; a default one was created when I set the datasource of the datagrid. I have not written any code to fire an update. The updates that are occurring are happening automatically. Can you tell me how to manually fire the update? I checked out bindingsource on msdn but there is no method that explicitly states it will update the datasource. Thanks for your help! Just to make it clearer, here is the code where I beleive the trouble
lies: Private Sub ImageEdit_SaveButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ImageEdit_SaveButton.DoubleClick Dim AllStringData_Dataview As DataView = New DataView(VADP_DataSetMain.AllStringData) Dim AllStringDataRow As DataRowView Dim Changes(9) as string For Each AllStringDataRow In AllStringData_Dataview If AllStringDataRow.Row.RowState = DataRowState.Modified Then <i>' in the above two lines I am trolling for all rows in my dataset that have been changed. The only way to change them is manually ona datagrid that is bound to the dataset.</i> (load values of this row into new dataset for "changed" entries) VADP_DataSetMain.ChangedStringData.AcceptChanges() End If Next VADP_DataSetMain.AllStringData.AcceptChanges() ' this line removes the rowstate notations in preparation for the next time End Sub Now my problem seems to be that the last row of the datagrid that gets changed never shows up in the underlying dataset as changed. If I alter 4 rows on the datagrid, only 3 lines in the underlying dataset read modified. I could change ever cell on that last row, but without actually clicking on a new row, it won't read as changed. What I want is a way to force the final update of the datagrid to the dataset (or the datagrid to the bindingsource?). Do you know how to do this? Maybe someone has a better answer than I, but I suggest that you monitor the
CurrentCellChanged event in the datagrid. Note that this event triggers whenever the user clicks in the cell or when ANY changes are made. Also, this event will fire on a delete. <bida***@yahoo.com> wrote in message Show quote news:1171561444.343787.304540@h3g2000cwc.googlegroups.com... > Just to make it clearer, here is the code where I beleive the trouble > lies: > > Private Sub ImageEdit_SaveButton_Click(ByVal sender As > System.Object, ByVal e As System.EventArgs) Handles > ImageEdit_SaveButton.DoubleClick > Dim AllStringData_Dataview As DataView = New > DataView(VADP_DataSetMain.AllStringData) > Dim AllStringDataRow As DataRowView > Dim Changes(9) as string > > > For Each AllStringDataRow In AllStringData_Dataview > If AllStringDataRow.Row.RowState = DataRowState.Modified > Then > > <i>' in the above two lines I am trolling for all rows in > my dataset that have been changed. > The only way to change them is manually ona datagrid that > is bound > to the dataset.</i> > > (load values of this row into new dataset for "changed" > entries) > VADP_DataSetMain.ChangedStringData.AcceptChanges() > > End If > Next > VADP_DataSetMain.AllStringData.AcceptChanges() ' this line > removes the rowstate notations in preparation for the next time > End Sub > > Now my problem seems to be that the last row of the datagrid that gets > changed never shows up in the underlying dataset as changed. If I > alter 4 rows on the datagrid, only 3 lines in the underlying dataset > read modified. I could change ever cell on that last row, but without > actually clicking on a new row, it won't read as changed. > > What I want is a way to force the final update of the datagrid to the > dataset (or the datagrid to the bindingsource?). Do you know how to > do this? > What version of .Net are you using?
Robin S. --------------------------------------- <bida***@yahoo.com> wrote in message Show quote news:1171561444.343787.304540@h3g2000cwc.googlegroups.com... > Just to make it clearer, here is the code where I beleive the trouble > lies: > > Private Sub ImageEdit_SaveButton_Click(ByVal sender As > System.Object, ByVal e As System.EventArgs) Handles > ImageEdit_SaveButton.DoubleClick > Dim AllStringData_Dataview As DataView = New > DataView(VADP_DataSetMain.AllStringData) > Dim AllStringDataRow As DataRowView > Dim Changes(9) as string > > > For Each AllStringDataRow In AllStringData_Dataview > If AllStringDataRow.Row.RowState = DataRowState.Modified > Then > > <i>' in the above two lines I am trolling for all rows in > my dataset that have been changed. > The only way to change them is manually ona datagrid that > is bound > to the dataset.</i> > > (load values of this row into new dataset for "changed" > entries) > VADP_DataSetMain.ChangedStringData.AcceptChanges() > > End If > Next > VADP_DataSetMain.AllStringData.AcceptChanges() ' this line > removes the rowstate notations in preparation for the next time > End Sub > > Now my problem seems to be that the last row of the datagrid that gets > changed never shows up in the underlying dataset as changed. If I > alter 4 rows on the datagrid, only 3 lines in the underlying dataset > read modified. I could change ever cell on that last row, but without > actually clicking on a new row, it won't read as changed. > > What I want is a way to force the final update of the datagrid to the > dataset (or the datagrid to the bindingsource?). Do you know how to > do this? > <bida***@yahoo.com> wrote in message
Show quote news:1171488907.114832.36990@h3g2000cwc.googlegroups.com... Is it a DataGridView control?> Hello all, > > I have a Windows form datagrid which is bound to a datatable in a > dataset. I want changes that the user performs on the information in > the datagrid to be automatically reflected in the the underlying > datatable. > > For the most part this is working. Then sometimes it does not, and I > can't figure out why. It seems that if you change a given datagrid > row, and then click on a different datagrid row, the change generally > gets recorded. If you change a row, and do not click on a different > row, the change is generally NOT recorded, no matter how many cells on > that datagrid row you altered. I don't understand why this is, and > why it is not completely predictable. It also creates a problem for > users who might simply make a change and forget the extra step of > clicking somewhere else. > > What is the exact mechanism (event?) which causes the datasource of > the datagrid to be updated? Is there any way to force the datasource > to update itself? Any help would be appreciated. > Is it bound to a data source? It probably triggers the Validate() event when it moves from one row to another. If you are sitting in a row you have modified and the user closes the screen or does something like that instead of moving to another row, you should be triggering the EndEdit and Validate events yourself, like if they click on <Save> or <Close> or something like that. I know .Net 2.0; if you're using 1.1, I don't know how this applies, maybe something about calling EndEdit on the BindingContext. Robin S.  |
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