I am binding the grid view to a data table via ItemsSource. Everything is OK, however, the changes to the data source don't go only through the grid user interface, but may happen also by making programatic changes directly to the data source. For example a menu option may go trough some data table fields and change their values, or may add new rows to the data table. In that case I want the grid to be notified about the changes in those affected areas and redraw itself to show the changes. However, I cannot find any method that would sound like "Redraw" or "Invalidate". There is a method Rebind which actually does the job and which I am using, however, why do I want to rebind the entire grid if I am changing only one field? I want to redraw its corresponding cell only rather than rebinding the entire grid.
Is there any method, or a subscription to an event, where I can have the grid redraw specified areas.
Any code samples?
Thank you,
Cezar Mart

P.S. I investigated it in the meantime, and I learned I need to implement INotifyCollectionChanged in my DataTable.
Great, I did this way:
public class MyDataTable : DataTable, INotifyCollectionChanged
{

  protected override void OnRowChanged ( DataRowChangeEventArgs e )
  {
   base.OnRowChanged(e);
   if ( e.Action == DataRowAction.Add )
   {
    if ( CollectionChanged != null )
    {
     CollectionChanged ( this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add) );
    }
   }
  }

  public event NotifyCollectionChangedEventHandler CollectionChanged;

}

and later in the code:
MyDataTable tb = new MyDataTable();
grid.ItemSource = tb; // grid is of type RadGridView

Then I programatically add a new row to my data table and the OnRowChanged is invoked. Great, however, the CollectionChanged handler is always null, so it looks the grid is not listening to this event. How do I make listen?

Thanks

Hello

 

Is there, somewhere in the doc or on Internet, examples of projects with the OutlookBar?

 

And, by the way, examples of the other rad tools?

 

Thanks

 

Richard

 

Hello,

I have added a GridViewComboBoxColumn to my RadGridView but it takes three clicks to expose the actual dropdown to make a selection. I've looked at this thread but my bindings are not showing any data. Is there anything new or updated that allows a combo box to be embedded in a RadGridView column, the thread was from 2009. The other problem I had was that there was no SelectionChanged event on the GridViewComboBoxColumn. I found a work around for that issue but the selection changed would fire before the combo box had even dropped down it's selections and the user made a physical change. With this approach is it possible to use the RadComboBox SelectionChanged event?

What I'm looking for is a combo box inside the grid that is immediately available for change and that raises an event if it is changed. I don't like having to click three times to expose and change a combo box value.

Binding is as follows:
ctrlStatus.ItemsSource = _statusList;  Where _statusList is a List<string>



G

My date picker is bound to a DateTime field, but on the UI, the control allows the user to "delete" the value. This causes the validation to throw an error "Value '' cannot be converted". Is there any way to set the control to the current datetime when the user "deletes" the date in the box?

I'm also having this trouble with a bound combobox that doesn't allow null values. I want the user to be able to type in to select a value, but that means they can also remove the value (which causes the same error).

Hello,

I'm doing a small project and just upgraded to the latest version of WPF telerik control. In my project I had some drag and drop between grid and listbox. Pretty much the same as the one in the demo (http://demos.telerik.com/silverlight/#DragAndDrop/TreeToGrid) this one but the wpf version. I used to be able to drag my item from the list without any problem but now it just doesn't work. The new WPF demo does not seem to work too.

Any ideas to what is wrong?

thank you very much

Hi,

I want some columns show hyperlink, and I found GridViewHyperlinkColumn and GridViewDataColumn in RadGridView.

My question is how to include them into RadGridView dynamically base on custom logic?

for example, when the grid load first time only col1, col3 and col 5 need to display as hyperlink, but when same grid load second time, maybe col2, col5 and col8 need to display hyperlink, not col1 and col3.

Thanks.

Dear support team,

we're using your Chart control to display several charts in our WPF application and have massive problems with its performance. I'd like to describe the application design and hope you have an idea how we can improve the applications performance.

There is a TabControl with two tab items and in each of those are two charts. Only one chart is visible at any time, each chart contains two line series. The charts show measurement values which are reported every 100 milliseconds. These values are buffered and added to a ObservableCollection every second (actually just an implementation of IList and the notify interfaces to get the collection thread-safe). This collection is binded to the chart (MVVM). A measurement will take between one or two minutes, so there will be something around 1000 values for each chart.

You can find a screen shot of the application at http://dl.dropbox.com/u/36135015/telerik%20forum/chart%20performance/GuiScreen.png

At the beginning of a measurement switching tabs or the visibility in each tab is possible without any delays but the more values we're adding to the charts, the longer the delay is getting. After some time the application gets unusable as the UI thread is busy wile drawing(?) the chart. Important to mention: the target system is an embedded Windows 7 system with an Intel Atom CPU N270 (1,6GHz) and 1GB of RAM. Nevertheless, the delays can be noticed at our development system, too (Intel i5 2,67GHz, 8GB RAM).

We took some advices of the support center or common wpf advices like buffering values, changing the control template, using VirtualizingStackPanel but there's no remarkable difference.

Why is the chart getting so slow (in my opinion the drawing can't be that expensive) and are there other possibilities to fasten it up?

I made a small demo project that uses a tab control to show four charts and fill them with data each 100 milliseconds. You'll notice that after something around 20-30 seconds the tab item changes will get remarkable slower. You can find it here: http://dl.dropbox.com/u/36135015/telerik%20forum/chart%20performance/ChartPerformance.Demo.zip

Sincerly yours,
Matthias

In a GridView with a lot of rows I would in first column only unique value shown; this means the cell text should be empty if the value of the cell is the same as the value in the prior row.
How can I do this?

Its a little bit similar to grouped columns

best regards

Andreas Manz

Hi,

I want to use xaml for binding nested collections to the the RadChart. However I don't want to hard code each series mapping manually like the examples show when they make use of multiple datasources or collection index.

As I can draw N number of series on chart at a given time hence hard-coding the series is impractical. Therefore I wanted to know how to handle this case in the most elegant way, by purely using Xaml and databinding the following data structure.



Thanks,
Farhan

In a screen's add mode, I woiuld like the MakedDateTimeInput control to start displaying an empty text box.  Setting the text property to empty string or null doesnt' work.  Is there a way to get this behavior with the MaskedDateTimeInput control?