Error deleting datagrid row

I'm getting an error of There is no row at position 6. when I tried to delete row six from the datagrid. In fact, I tried all the rows in the datagrid and still receiving the same error message. Here's what tried before:

Quote:

---

Dim dgRowNumber As Integer = dgComputer.CurrentRowIndex

Try
DSetProgram.Program.Rows(dgRowNumber).Delete()
Catch exError As Exception
MessageBox.Show(exError.Message)
End Try
DAdptProgram.Update(DSetProgram.Tables("Program"))
DSetProgram.Tables("Program").AcceptChanges()

---

But still it gives me the error that there is no row at the position of the variable "dgRowNumber". So I tried this:

Quote:

---

dsUsrProfile.Tables("strTableName").Rows(dgRowNumber).Delete()
DAprofile.Update(dsUsrProfile.Tables("strTableName"))
dsUsrProfile.Tables("strTableName").AcceptChanges()
If (dsUsrProfile.HasChanges) Then
MsgBox("Changes has been committed")
End If

---

But the same error happened. However, I have a total of 6 rows in the table called "Program". In addition, when the program runs, the variable "dgRowNumber" do have an actual number that corresponds to the datagrid. If this variable would to contain some number that is not relating to the datagrid or out of the range then yes, I understand but it's not. It is within the range of the rows in the datagrid and database table.

ljCharlie

VB Code:

Dim dgRowNumber As Integer = dgComputer.CurrentRowIndex [b]-1[/b]

Thanks for suggestion; however, that is not the problem. I tried your suggestion and it's still not working. The error is still the same. The number after the word "position" corresponds to whatever row I select in the datagrid but it just gives me an error. Like I said, it's not like the row number is out of range. It is still within the range.

ljCharlie

I figured out a part of the problem is when I test the code on another dataset and dataadapter using the same datagrid; however, I don't know how to solve it or detect it. Here's what I found out.

In this statement:Dim dgRowNumber As Integer = dgComputer.CurrentRowIndex

The code suppose to find the row that I select to be deleted and it did show the correct row number I want to delete. In this statement: DSetProgram.Program.Rows(dgRowNumber).Delete() , the dgRowNumber still show the correct row number to be deleted. However, when the code finish executing, the record that was deleted wasn't the one that I specify to be deleted. I tried this a couple of times and it seems to be that the deletion was random or it appears to be random despite what row I specify to be delete!

So my question is, how/why this happen and how do I fix the problem?

ljCharlie

Regarding the Random deletion; well, it's not true. It depends on the arrow of the header in each of the columns in the datagrid pointed at. If the arrow pointed up, then the deletion starts at the bottom. If the arrow pointed down, then the deletion starts at the top regardless of what row I specify to be deleted.

Any clue why this is happening and how do I fix this?


Many thanks for the help so far.

ljCharlie

Did you set any property to sort data on the Grid ? or do you know if the data on the Grid is sorted same way as in source database ?

If the above is true , then you need to validate selected row not by index number but using real data .

I think you're right. I need to validate my selected row by using real data. The question is I don't know how to do that. Mind showing me how or pointing me to an article that will show me how to do that?

Thank you,

ljCharlie

Sure , I'll give it a shot .

Sorry for taking long time . It's here . VB.NET 2003 , If you don't have it , get the converter under my signature .

Thanks for helping me out. Unfornately, I wasn't able to unzip that file. When I tried to unzip the file, the program gives me an error of "Bad header". I don't know what that means. Anywa, will you zip the project into .zip instead of .rar?

Thank you,

ljCharlie

Instead , you could downloaded Winrar and unpack it rather than waiting again . ;) . I like winrar because of that I always keep it installed .

OK . It's winziped pack .

Again, thank you very much giving up your time to help me.

If I would to do it the way your sample showed me then that means I'm not using ADO.NET at all correct? I thought ADO.NET supose to make datagrid editing a lot easier. This is the manual way though. Because I'm using design mode to create my dataset and dataadapter, is it possible for me to just call one of those already generated queries to delete the row I want? I remember that there is a way; however, I don't remember how to call the delete SQL query instead of writing from scratch, since I'm jusing a dataset that was creaed at design time.

ljCharlie

ADO.NET is the underlying structure for the databases , tables , columns ..etc . So , it's completely isolated from DataGrid or any other control . So as soon you declare any ADO.NET obj (connection , table , column..etc) , then you're using ADO.NET .

For me , I hate those database controls . I like to code them .

For the deleting issue , check the demo I posted above . It should show you how to use SQL Statement "DELETE" to delete a record .

Sorry if I'm still missing the point you're dragging my attention to .

I can do a manual delete with a SQL query. I thought it would be much easier just to specify which row to delete in the datagrid and the program will automatically delete it for me. Perhaps the DataGrid is not that useful then.

Well, thanks for all the help.

ljCharlie

I don't know if you are doing something supernatural and this DataGrid is no way good for your current proj . From what I saw , it still works good . Why not just specifying a unique word or number and let it handled by this SQL string . I did it in a way , it builds the string easily avoiding error generations . I'm trying to force you to do that but what's the real problem now ?

Guess what? I got something weard going on here. Somehow it works if I created a textbox and just enter a row number into this textbox and leave everything the same; however, instead of using the CurrentRowIndex, I'm using the number from the textbox to make my deletion and it seems to work. Now, I have not test this on when I sort the datagrid. But my question is, why is this working?

ljCharlie

If you are using the current row index then set your data row as follows

dim currow as integer = MyDatagrid.CurrentRowIndex

dim mydatarow as datarow

mydatarow = mydataset.tables.ite("MyDataset").Rows.RemoveAt(currow)

that should do the trick!

There is a blue underline beneath the line when I tried this:

mydatarow = mydataset.tables.ite("MyDataset").Rows.RemoveAt(currow)

What is ite? I tried without that and it still gives me the blue underline. I tried putting the word "Item" and still giving the same thing. for the "MyDataSet", I put my database Table name and still same blue underline. I tried putting the name of my DataSet in and the same thing happend.

ljCharlie

Maybe he means something like this :

VB Code:

dr = ds.Tables("tablename").Rows.RemoveAt("indexnumber")

yes the ite was a mistype, you will also need to Dim your dataset as in

Dim MyDataset as new dataset, put it before the dim MyDatarow

Remove the quotes surrounding the indexnumber .

So it should something like this:

Quote:

---

Dim MyNewDataSet As New DataSet

Dim currow as integer = MyDatagrid.CurrentRowIndex

Dim mydatarow as DataRow

mydatarow = mydataset.tables(MyNewDataSet ).Rows.RemoveAt(currow)

---

ljCharlie

No Pirate I didn't mean




dr = ds.Tables("tablename").Rows.RemoveAt("indexnumber")

since the parameter for RemoveAt has to be an integer and should match, the row number you are on the datagrid, usually the one you selected by clicking aand saving the row number for another event to remove

Without double quotes .

VB Code:

dr = ds.Tables("tablename").Rows.RemoveAt(indexnumber)

but are you sure that this record is the same one as in the Grid?

SQL string I think is the good way to go with . It's your choice ...:p

If what I'm looking for works then I want to try that route first. As far as SQL string, I know how to do that...the only problem I have right now is that I'm too far in the project that I don't want to start all over by writing every SQL string in my project just to accomodate the delete routine.

ljCharlie

Yes thats right but just remember I have left out all the code to populate that datagrid first as written it would be ridiculous as you have nothing to remove.

Basic order here, create dataset and populate
Bind datagrid to dataset

You must already have done this in your application I feel sure

Now you have a datagrid populated with data and you want to remove one item

The basic technique I use, is to react to the click event on the datagrid and save the currentrow index in an integer variable

Then have what is effectively a remove button

When they click that, first of all I check that the saved current row index is selected and if so use the remove at method to remove it from the displayed items in the datagrid

In the meantime if you could look at my thread called the The downside of Application.Enablestyles and offer any insights, boy would I be grateful!!!

Your problem is covered in the VB.Net help although I know that VS 2003 is shippped without help and they tell you install MSDN help, yes all 2gb of it, I rely on the help I got with VS 2002 or MSDN itself and finally here.

RichardAtherton, thanks for the help. However, I have one more question before I implement the code. Why do I need to declare a New DataSet variable to put into this mydatarow = mydataset.tables(MyNewDataSet ).Rows.RemoveAt(currow). I already created a dataset and dataadapter at design time. So what's the purpose declaring the MyNewDataSet again?

ljCharlie

maybe that was a crossover from my last post, no of course you don't have to create a new dataset,Ijust wrote some code that would not have any syntax errors.

I did assume that you already had a populated dataset and simply wanted to manipluate it.

I tried and still not working. I mean there is a blue underline when I wrote this line:

mydatarow = mydataset.tables("myTable" ).Rows.RemoveAt(currow)

ljCharlie

Ok here is some actual working code! with no blue lines, of course anything not Dim has been dim elsewhere and is known to this routine

FindResult.item is a shared class, with a variable for storing and retrieivng an integer value representing the current row index

If FindResult.Item = -1 Then Exit Sub
Me.Cursor = Cursors.WaitCursor
dr5 = ds5.Tables.Item("RentAdjustmentsList").Rows(FindResult.Item)
TotalAdj = TotalAdj - dr5("Amount")
DecTxtBox3.Text = Format(TotalAdj, "##,##0.00")
ds5.Tables.Item("RentAdjustmentsList").Rows.RemoveAt(FindResult.Item)
Me.Cursor = Cursors.Default
Button5.Visible = False
NumTxtBox1.Focus()

dr5 is a DataRow, correct? And FindResult.Item contains the CurrentRowIndex as an Integer, correct?

ljCharlie

yes dr5 is a datarow and findresult.item hold the currentrowindex

First of all, any time when I do this:
dr5 = ds5.Tables.Item("RentAdjustmentsList").Rows(FindResult.Item) , with the datarow variable, I get a blue underline. Secondly, the RemoveAt dosn't work. It's not deleting the row in the datagrid. It only delete when I when use the word "Delete", but again, it's not deleting the selected row.

ljCharlie

ok I give up don't know what is wrong, all I know is the code works for me

Many thanks for the effor though. I was going to attach my project to this thread; however, looks like this site only allow 100K and my zip file is over 300K.

Well, thanks for trying.

ljCharlie

Remove the bin and obj folders . Zip up the proj , if still too big , then post it in two separate posts (proj + database)

Here it is. I break it to two zip files.

ljCharlie

Here is the second file. Put the .mdb file inside the bin and the Icons folder under the Computer.

ljCharlie

OK , I downloaded the proj . Promise to look into it tomorrow .I'm dead tired by now .
:)

Sorry for taking too much of your time. I'm greatly appreciate the time you spend on helping me out.

Thanks again.

ljCharlie

jog my memory on your annoying problem ? If it's deleting a a row according to its row index in theGrid but it's actually deleting another record or is it something else ?

It's not deleting the selcted row. It deletes some other row in the datagrid instead.

ljCharlie

Nothing wrong with your code when I tried it . I disabled the code inside clsDGComputer.vb and tried and no longer removing unspecified row . It seems to me that that code is a little bit buggy . Just add a row number in the txtRowNumber textbox and try it .

Have you tried sorting? Usually sorting is the cause of the problem.

ljCharlie

Yes , it's true . When sorting the grid ascendingly , it deletes rows from hightest point and vice versa . If you really don't need that sorting thingy, then I'll try to find a way around .

Thanks for the help. I think I figured it out.

ljCharlie

I hope so . Well , I was just trying to bind a context menu with the right click on any cell or row and select from the menu 'Delete' and it copy where the click is and perforum the operation . Happy coding ;)

Yes, that's a good idea. You're talking about right click on a row or cell and a menu showed up with options such as delete, update, edit etc.. right?

ljCharlie

Exactly . Your app may needs some additions like "Show tip" for the control bar , you can add more features also as context menu beside the bottons . Lastly , you are missing very important issue which distinct VB.NET lang from VB6 , it's OOP . You could have made your code re-usable in your future proj by putting these methods in a form that's not bounded to this proj only . You've done something cool , keep it up .

Thanks for help though. I know I still need a lot of the features...and perhaps when I'm at that stage I hope you'll still be here to answer some of my very basic questions.

By the way, what is OOP?

ljCharlie

It's Object Oriented Programming . It a way of organizing a program into logical components like Classes then Methods (Sub ,Functions and properties) . It makes a lot of sense esp in .NET . For example : A car obj (consider it as a program) . It may contains these objects : Wheels , engine , body , seats...etc . You can work on each of these objs separatly and isolated from the other obj . Then you can incorporate these objs (actually the methods in them) into the program to make the car work . It requires reading .

If that doesn't make sense (I'm sure it doesn't), then stop reading ....lol :D . There are thousands of pages on this topic .

I remember what OOP is now.

By the way, how do I refresh the datagrid to reflect what I have just inserted into the database file?

ljCharlie

I've tried refresh method but i doens't do it . Just call the same sub again (the sub you're using to iterate the Grid) .

Here's what I have tried:

DataGrid1.Refresh()
DataGrid1.DataSource = DataSet1.table1
DataSet1.Clear()
DataAdapter1.Fill(DataSet1)

But this is still not working. If I shut down the program and restart it again then it shows the latest records. But this is so inconvenience.

ljCharlie

Did you call the procedure itself rather than doing the above ? That's the way I do always .

The procedure that populate the datagrid is the same as above except the datagrid.refresh method wasn't included.

ljCharlie

How come you bind a dataset or whatever before you refill it ? Fill then bind the dataset .

I tried fill first then bind them but still not working. This time I called the initial procedure that fill the datagrid at the begining but still not reflecting the inserts.

ljCharlie

Since I still have the source code :o , In which part you're having troubles?