"David Mayerovitch" <davmay@sympatico.ca> wrote in message
news:%23Nmt2fKLHHA.1424@TK2MSFTNGP04.phx.gbl...
> As an exercise in learning Visual Basic 2005, I am putting together a
> simple
> XML editor.
>
> I place on the form the objects DataGridView1 and DataSet1.
>
> ' Read an XML file into DataSet1:
> DataSet1.ReadXml("BIRDS.XML")
>
> ' Bind the DataGridView to the DataSet:
> DataGridView1.DataSource = DataSet1
>
> ' Having determined that the TableName of the
> ' DataTable I am interested in is "bird",
> ' make this the DataMember of the DataGridView:
>
> DataGridView1.DataMember = "bird"
>
> ' Set up autogeneration of columns:
> DataGridView1.AutoGenerateColumns = True
>
> And now the contents of the file appear in the grid for viewing and
> editing.
> OK so far.
>
> But now I want to load in a new file. When I load "MUSICIANS.XML",
> with its
> DataMember "musician", the existing data from "BIRDS.XML" is not
> overwritten. It either remains as it is within the grid and the
> MUSICIANS
> data fails to appear, or, depending on the structure of the new file,
> the
> new data may be appended to the existing data. The number of columns
> and
> their headings remain what they were instead of reflecting the
> structure of
> the new file. Sometimes no data appears under these headings after the
> loading of the new file.
>
> Obviously I need some way of re-initializing the DataSet or the
> DataGridView
> or both before loading a new file. I have been able to do this only by
> re-instantiating the DataSet on each pass:
>
> Dim DataSet1 As New DataSet
>
> This gets rid of all previous data and I can load different files in
> succession. But it's not a good solution because instantiating the
> DataSet
> within a Sub means, I assume, that it won't be visible to other
> routines
> that I'll need for saving data back to a file. And it's probably bad
> for
> other reasons too.
>
> I tried setting
> DataGridView1.DataSource = Nothing
>
> but this didn't work.
>
> Neither did
> DataSet1.Clear()
>
> So can anyone tell me how to re-initialize the DataSet and/or the
> DataGridView so that I can load new files cleanly? I couldn't find
> anything
> in the documentation. (If there is an explanation somewhere, please
> point me
> to it.)
>
> Thanks.
> David
>
>

"RobinS" <RobinS@NoSpam.yah.none> wrote in message
news:Eu-dnfO4WbDN9ArYnZ2dnUVZ_sSmnZ2d@comcast.com...
> As I posted in the other ng where you posted this question,
> try DataSet1.Reset()
>
> Robin S.
> ----------------------------------------
> "David Mayerovitch" <davmay@sympatico.ca> wrote in message
> news:%23Nmt2fKLHHA.1424@TK2MSFTNGP04.phx.gbl...
>> As an exercise in learning Visual Basic 2005, I am putting together a
>> simple
>> XML editor.
>>
>> I place on the form the objects DataGridView1 and DataSet1.
>>
>> ' Read an XML file into DataSet1:
>> DataSet1.ReadXml("BIRDS.XML")
>>
>> ' Bind the DataGridView to the DataSet:
>> DataGridView1.DataSource = DataSet1
>>
>> ' Having determined that the TableName of the
>> ' DataTable I am interested in is "bird",
>> ' make this the DataMember of the DataGridView:
>>
>> DataGridView1.DataMember = "bird"
>>
>> ' Set up autogeneration of columns:
>> DataGridView1.AutoGenerateColumns = True
>>
>> And now the contents of the file appear in the grid for viewing and
>> editing.
>> OK so far.
>>
>> But now I want to load in a new file. When I load "MUSICIANS.XML", with
>> its
>> DataMember "musician", the existing data from "BIRDS.XML" is not
>> overwritten. It either remains as it is within the grid and the MUSICIANS
>> data fails to appear, or, depending on the structure of the new file, the
>> new data may be appended to the existing data. The number of columns and
>> their headings remain what they were instead of reflecting the structure
>> of
>> the new file. Sometimes no data appears under these headings after the
>> loading of the new file.
>>
>> Obviously I need some way of re-initializing the DataSet or the
>> DataGridView
>> or both before loading a new file. I have been able to do this only by
>> re-instantiating the DataSet on each pass:
>>
>> Dim DataSet1 As New DataSet
>>
>> This gets rid of all previous data and I can load different files in
>> succession. But it's not a good solution because instantiating the
>> DataSet
>> within a Sub means, I assume, that it won't be visible to other routines
>> that I'll need for saving data back to a file. And it's probably bad for
>> other reasons too.
>>
>> I tried setting
>> DataGridView1.DataSource = Nothing
>>
>> but this didn't work.
>>
>> Neither did
>> DataSet1.Clear()
>>
>> So can anyone tell me how to re-initialize the DataSet and/or the
>> DataGridView so that I can load new files cleanly? I couldn't find
>> anything
>> in the documentation. (If there is an explanation somewhere, please point
>> me
>> to it.)
>>
>> Thanks.
>> David
>>
>>
>
>

"David Mayerovitch" <davmay@sympatico.ca> wrote in message
news:eiRh1YQLHHA.3564@TK2MSFTNGP02.phx.gbl...
> Thanks, Robin - That's just what I needed!
> David
>
> "RobinS" <RobinS@NoSpam.yah.none> wrote in message
> news:Eu-dnfO4WbDN9ArYnZ2dnUVZ_sSmnZ2d@comcast.com...
>> As I posted in the other ng where you posted this question,
>> try DataSet1.Reset()
>>
>> Robin S.
>> ----------------------------------------
>> "David Mayerovitch" <davmay@sympatico.ca> wrote in message
>> news:%23Nmt2fKLHHA.1424@TK2MSFTNGP04.phx.gbl...
>>> As an exercise in learning Visual Basic 2005, I am putting together
>>> a simple
>>> XML editor.
>>>
>>> I place on the form the objects DataGridView1 and DataSet1.
>>>
>>> ' Read an XML file into DataSet1:
>>> DataSet1.ReadXml("BIRDS.XML")
>>>
>>> ' Bind the DataGridView to the DataSet:
>>> DataGridView1.DataSource = DataSet1
>>>
>>> ' Having determined that the TableName of the
>>> ' DataTable I am interested in is "bird",
>>> ' make this the DataMember of the DataGridView:
>>>
>>> DataGridView1.DataMember = "bird"
>>>
>>> ' Set up autogeneration of columns:
>>> DataGridView1.AutoGenerateColumns = True
>>>
>>> And now the contents of the file appear in the grid for viewing and
>>> editing.
>>> OK so far.
>>>
>>> But now I want to load in a new file. When I load "MUSICIANS.XML",
>>> with its
>>> DataMember "musician", the existing data from "BIRDS.XML" is not
>>> overwritten. It either remains as it is within the grid and the
>>> MUSICIANS
>>> data fails to appear, or, depending on the structure of the new
>>> file, the
>>> new data may be appended to the existing data. The number of columns
>>> and
>>> their headings remain what they were instead of reflecting the
>>> structure of
>>> the new file. Sometimes no data appears under these headings after
>>> the
>>> loading of the new file.
>>>
>>> Obviously I need some way of re-initializing the DataSet or the
>>> DataGridView
>>> or both before loading a new file. I have been able to do this only
>>> by
>>> re-instantiating the DataSet on each pass:
>>>
>>> Dim DataSet1 As New DataSet
>>>
>>> This gets rid of all previous data and I can load different files in
>>> succession. But it's not a good solution because instantiating the
>>> DataSet
>>> within a Sub means, I assume, that it won't be visible to other
>>> routines
>>> that I'll need for saving data back to a file. And it's probably bad
>>> for
>>> other reasons too.
>>>
>>> I tried setting
>>> DataGridView1.DataSource = Nothing
>>>
>>> but this didn't work.
>>>
>>> Neither did
>>> DataSet1.Clear()
>>>
>>> So can anyone tell me how to re-initialize the DataSet and/or the
>>> DataGridView so that I can load new files cleanly? I couldn't find
>>> anything
>>> in the documentation. (If there is an explanation somewhere, please
>>> point me
>>> to it.)
>>>
>>> Thanks.
>>> David
>>>
>>>
>>
>>
>
>