Questions on UI for WPF Forum

2 answers

181 views

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).

DatePicker

answered on 11 Aug 2011

10 answers

362 views

[Solved] Can't drag from ListBox

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

DragAndDrop

answered on 11 Aug 2011

7 answers

408 views

Determine Grid column type at runtime

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.

GridView

answered on 11 Aug 2011

1 answer

197 views

Chart is getting slower with increasing number of values

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

Chart

answered on 11 Aug 2011

1 answer

118 views

Only first value of column shown

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

GridView

answered on 11 Aug 2011

3 answers

198 views

Databinding to nested collections

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.

public class Data : INotifyPropertyChanged

{

private double m_Value;

private int m_Period;

public event PropertyChangedEventHandler PropertyChanged;

public double Value

{

get

{

return m_Value;

}

set

{

if (m_Value == value)

return;

m_Value = value;

this.OnPropertyChanged("Value");

}

public int Period

{

get

{

return m_Period;

}

set

{

if (m_Period == value)

return;

m_Period = value;

this.OnPropertyChanged("Period");

}

protected virtual void OnPropertyChanged(string propertyName)

{

if (this.PropertyChanged != null)

this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));

}

public class DataPointSeries : INotifyPropertyChanged

{

private ObservableCollection<Data> m_DataList;

public ObservableCollection<Data> DataList

{

get

{

return m_DataList;

}

set

{

m_DataList = value;

OnPropertyChanged("DataList");

}

public event PropertyChangedEventHandler PropertyChanged;

protected virtual void OnPropertyChanged(string propertyName)

{

if (this.PropertyChanged != null)

this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));

}

public class ChartsViewModel

{

private ObservableCollection<DataPointSeries> m_DataPointSeriesCollection;

public ObservableCollection<DataPointSeries> DataPointSeriesCollection

{

get

{

return m_DataPointSeriesCollection;

}

set

{

m_DataPointSeriesCollection = value;

}

public void PopulateDataSeriesCollection()

{

DataPointSeriesCollection = new ObservableCollection<DataPointSeries>

{

new DataPointSeries

{

DataList = GetDataPoint(0)

},

new DataPointSeries

{

DataList = GetDataPoint(12.75)

},

new DataPointSeries

{

DataList = GetDataPoint(27.625)

},

new DataPointSeries

{

DataList = GetDataPoint(37.675)

},

new DataPointSeries

{

DataList = GetDataPoint(43.475)

}

};

}

public ObservableCollection<Data> GetDataPoint(double factor)

{

var dataList = new ObservableCollection<Data>()

{

new Data

{

Period = 2002,

Value = 15 + factor

},

new Data

{

Period = 2003,

Value = 25 + factor

},

new Data

{

Period = 2004,

Value = 35 + factor

},

new Data

{

Period = 2005,

Value = 55 + factor

},

new Data

{

Period = 2006,

Value = 65 + factor

},

new Data

{

Period = 2007,

Value = 75 + factor

}

};

return dataList;

}

Thanks,
Farhan

Chart

answered on 11 Aug 2011

2 answers

125 views

Masked Input - DateTime

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?

MaskedInput (Numeric, DateTime, Text, Currency)

answered on 11 Aug 2011

1 answer

164 views

[Solved] Dragging and Dropping to RadMap

Is it possible to drag and drop items from a ListBox onto a RadMap control? I have the telerik:RadDragAndDropManager.AllowDrop="True" attribute set on the RadMap control, but I don't ever see the DropInfo event being raised. The DragQuery and DropQuery events seem to be raised just fine, but since I never get a DragStatus.DragComplete status, I'm not ever sure where to drop the item.

DragAndDrop

answered on 11 Aug 2011

3 answers

279 views

[Solved] Close button in each radpane tab

Hello,

I'm looking for putting the close button next to the header of the radpane. It will be useful for us.
Someone knows how to do it or give me some info?

Regards.

Docking