I've set up a simple data bound gridview that is populated via the autogenerated code for winforms. It is filling based off of the dataset I point it at.
I've updated the underlying database it's supposed to be filling off of to add an additional column to a table. However this added column is not appearing in the gridview.
I have deleted the datset and rebound it and can't find an answer online but am probably searching with incorrect terms. Is there a way to refresh the dataset in some way?
How the gridview is being filled is by:
this.xTableAdapter.Fill(this.DBDataSet.tableName);
I imagine there is a simple way to refresh the underlying dataset but cannot for the life of me find what it is.
This link had the answer. I needed to go into the dataset designer view and right click on the get, fill() query in the query area for my table. Doing so allowed me to modify the query that built the dataset, adding in the missing column.
Related
I have a datatable in code. And the datagridview in the Ui.
In code I have done gridviewName.DataSource = dtTable1
Now in the UI I can see gridview populated with the table data. In the UI gridview I can update the cell values and/or delete the data rows. Upon doing any changes to the gridview, the changes automatically flow back into the data table.
I am bit confused at this point because I had thought it is a 1 way connection from data table into datagridview. Is this 2 way by design? If yes, then subsequently if I want to perform an operation per row, like send an email per row, then it is recommended to iterate over the gridview or the data table?
Yes, the 2 way data flow is by design; it makes creating applications a lot easier. If you don't want your user to edit a grid you make the grid read only, but typically you show data to a user, you let them edit it and save it. That would get a lot more hard work if you made data binding a one way thing the grid is connected to the datatable directly; it doesn't copy the data it finds into its own internal data array
Always loop over the datatable, read it and edit it directly; the grid will update accordingly; always avoid looping over the datagridview. As the embodiment of model-View-controller your code should manipulate the model (datatable) not try and manipulate the model via the view/controller that is intended for the user (the datagridview)
If you add a DataSet type file to your project and design a strongly typed datatable inside it your life gets easier. Your code looks like:
foreach(var r in soneDataset.EmailQueueDataTable){
mailer.Send(r.From, r.To, r.Subject, r.Message, r.RetryAttempts);
}
With a standard datatable everything is done with string column names or worse, ordinal positions and needs casting:
foreach(DataRow r in EmailQueueDataTable.Rows){
mailer.Send((string)r["From"], (string)r["To"], (string)r["Sujbect"], (string)r["Message"], (int)r["RetryAttempts"]);
}
Intellisense won't help you with the column names either; you'll only find out at runtime that I made a typo in Subject
I have a GridView and a SqlDataSource. All binding done in aspx, works correctly and Select calls an SP with parameters.
Now I would like to access the bound data programmatically, in stuctured form, not parsing back it from the UI, using cells or .FindControl or other hacks. I also do not want to reselect the data using my SqlDataSource's Select.
I've debugged the code but can not find any structured data neither in my GridView variable neither in my SqlDataSource variable. Maybe I was browsing the wrong properties or a cast was missing.
Thx in advance
I don't think you can do that. When you bind the data from an SQL DataSource to a Gridview, it fetches the data to display and then that's it. It's gone.
When a GridView updates the data, it uses the key field ID and the text in the GridView to do it. There is no other DataTable or other structure behind the scenes.
Ok so I'm trying to make a simple SQL CE Viewer application just to view my local databases for another application, I have it setup so that I can select what database I want to open and then it automatically populates a combo box with all of the tables in the database. When I select a table it populates a DataGridView with the records in the table.
My problem is switching between tables. I can't seem to get the DataGridView to remove everything from the previous table and re-populate the DataGridView with the new table information. Of course each table has different columns and rows and such.
I've googled and searched on here and every suggestion I find doesn't seem to work. It populates the DataGridView with the first table just fine, but when I select another it basically adds the columns and rows into whatever was there....
How can I get the DataGridView to completely clear for new data?
And please don't tell me to use dataGridView1.DataSource = null; tried that, doesn't work.
Well, I checked it in one of my programs and just changing DataSource property is working fine. I didn't have to use datagridview.Refresh(). Maybe it depends on the kind of DataSource, which you are using to set datagridview data?
Write this line after you have done populating the DataSource with the new data
dataGridView1.Refresh();
You don't need to clear the DataGridView directly. Its always handled by modifying the DataSource of the DataGridView.
If there is nothing else in the form, you can simply call InitializeComponent() again. But I think #Josh is right.
I have C# application that fills a GridView with data from a DataTable object, which is filled from parsing a text file. Now i want to do a master-detail scheme, where the master GridView shows an identifying column from the DataTable for all rows, and the detail GridView shows all the columns for that row.
All the examples I'm finding seem to require a SqlDataSource control (to provide the filtering mechanism), which then requires a connection to a database. I can't find how to provide this information when using only a DataTable data source. What provider would I use, and what would the connection string look like?
Thanks in Advance for any help.
You already have your DataSource (unless the data will change when you click a GridViewRow), so all you need is to get something like a Key from your current GridView, create a new DataSource by loading data from your DataTable with the selected key in your GridView and bind it to your new GridView. I could also suggest that you take a look to the DetailsView control which is designed to do in fact what you are trying to accomplish here (master-details scheme).
Good luck my friend.
No connection string needed. You already have the data in a DataTable, so you should be able to do something along the lines of:
myGridView.DataSource = myDataTable;
myGridView.Databind();
I have problem with updating my datagridview after inserting new data to table. It seems DataSet ,to which datagrid is bound, does not refresh and i cant force it to do so.The only way to refresh dataset is to reset application. I know i can make new DataSet and fill it with table's data every button "Refresh" click ,but i wonder if its simpler way.
I googled a little, but non of these solutions work for me :
bindingSource1.EndEdit();
bindingSource1.ResetBindings(false);
dataGridView1.EndEdit();
dataGridView1.Refresh();
dataGridView1.Parent.Refresh();
dataSet1.GetChanges();
this.TableAdapter.Fill(this.dataSet1.Table1);
dataGridView1.Invalidate();
Where the problem lies?
Changes to the dataset will be reflected in any bound grids. But it sounds like what you're asking is how to make the DataSet itself update in response to changes in the underlying database table. There's nothing automatic in .NET or MSSQL for this. You basically have to just re-run your query. You want to have a look at the ClearBeforeFill property of the table adapter so that you are not blowing away existing data when loading in new changes.
Have a look at this article for more information.