Questions on UI for WPF Forum

1 answer

372 views

GridView can't handle DBNull in dynamic data row

I am dynamically loading a small amount of data from a Sql Server table using the dynamic data row concept in this example.
Everything is working however if one of the values is DBNull then when the column is sorted the grid displays as blank. Toggling the sort back to off shows the data again.

To solve this I am simply casting to null when the value is DBNull.

var value = reader.GetValue(x);

row[column] = value == DBNull.Value

? null

: value;

This sounds to me like a bug.

GridView

answered on 29 Aug 2016

1 answer

583 views

RadDatePicker: Disable / Hide Weekends

Hi

I have a requirement to hide weekends to show up on the dropdown calendar control in RadDatePicker for WPF. I have gone through lots of google posts and telerik forum posts but couldn't find a way to do this. Is there a way to acheive this? If this is not possible, is there a easier way to disable selecting the weekends? The BlackoutDates collection won't work for me as i will need to insert all weekend dates from 1970 in to it and it is not a workable solution for us.

Thanks

Vinoth

DatePicker

answered on 29 Aug 2016

2 answers

132 views

Label with mnemonic at first character rendering problem

Hi,

I use 2015 Q2. When I add mnemonic to label this way:

<telerik:Label Target="{Binding ElementName=InputName}" Grid.Row="0" Content="_Nazwa:"/>

<telerik:RadMaskedTextInput x:Name="InputName" Grid.Row="0" Grid.Column="1"/>

my label has additional margin at the beginning (space for non-existent underscore character?). Please see attached file.

When I remove underscore then label is aligned properly.

What can I do about it?

General Discussions

answered on 29 Aug 2016

2 answers

376 views

How to make the shape to the viewport's center?

Hi, I want a RadDiagramShape display in the viewport's center, there are many shapes in the RadDiagram. How to do it ? I found the diagram's viewport.X and viewport.Y, but they are read-only, can not to set. Thanks!

Diagram

answered on 27 Aug 2016

1 answer

827 views

List of icons

Hello,

Right now i am implementing a search button for my PDF toolbar.

all i need is the right icon. but i dont seem to find a list of the icons available

{telerik:IconResource IconRelativePath=SEARCH_ICON_goes_here.png, IconSources={StaticResource IconPaths}

can someone help please?

thanks

General Discussions

answered on 26 Aug 2016

3 answers

193 views

TreeListView with a ListCollectionView is leaking the performance

I took an example for a TreeView where you filter items with a Boolean "IsRemovedByFilter". The example had the items re-created with a copy constructor.

I did the same on a tree list view, and replaced the copy constructor with ListCollectionView.EditItem and CommitEdit.

The more times you filter the items, the slower it gets.

Here is the code:

MainWindow:

<Window x:Class="TreeListView_Filtering_Issue.MainWindow"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"

Title="MainWindow" Height="350" Width="525">

<Grid>

<Grid.RowDefinitions>

<RowDefinition Height="Auto"/>

<RowDefinition />

</Grid.RowDefinitions>

<TextBox Text="{Binding FilterText, UpdateSourceTrigger=PropertyChanged}" />

<telerik:RadTreeListView ItemsSource="{Binding Items}" AutoGenerateColumns="False" Grid.Row="1">

<telerik:RadTreeListView.ChildTableDefinitions>

<telerik:TreeListViewTableDefinition ItemsSource="{Binding FilteredChildren}" />

</telerik:RadTreeListView.ChildTableDefinitions>

<telerik:RadTreeListView.Columns>

<telerik:GridViewDataColumn DataMemberBinding="{Binding Name}" IsReadOnly="True"/>

</telerik:RadTreeListView.Columns>

</telerik:RadTreeListView>

</Grid>

</Window>

The data context is being set by (just a quick and dirty way for this example):

public MainWindow()
{
InitializeComponent();
this.DataContext = new MainViewModel();
}

The ViewModels are:

public class MainViewModel : ViewModelBase

{

private ObservableCollection<Person> _persons = new ObservableCollection<Person>();

private ListCollectionView _items;

private string _filterText = string.Empty;

public MainViewModel()

{

for (int i = 0; i < 100; i++)

{

Person person = new Person(null)

{

Name = "Test" + i,

};

_persons.Add(person);

for (int j = 0; j < 20; j++)

{

Person child = new Person(person)

{

Name = "Child." + i + "." + j,

};

person.Children.Add(child);

}

_items = new ListCollectionView(_persons);

_items.Filter = nonFilteredChidrenPredicate;

}

internal static bool nonFilteredChidrenPredicate(object obj)

{

if (obj is Person)

{

return !(obj as Person).IsRemovedByFilter;

}

return false;

}

public ListCollectionView Items

{

get

{

return _items;

}

public string FilterText

{

get

{

return _filterText;

}

set

{

if (value == null)

value = string.Empty;

_filterText = value;

FilterItems();

}

internal void FilterItems()

{

Queue<Person> queue = new Queue<Person>();

foreach (var item in _persons)

{

queue.Enqueue(item);

}

while (queue.Count > 0)

{

Person current = queue.Dequeue();

current.IsRemovedByFilter = false;

if (current.Name.ToUpper().Contains(FilterText.ToUpper()))

{

current.IsRemovedByFilter = false;

//if (!string.IsNullOrEmpty(FilterText))

//{

// current.IsExpanded = true;

// if (selectedItem == null)

// selectedItem = current;

//}

// show and expand parent if one child fits with filter

setParentFilterStatus(current);

}

else

{

current.IsRemovedByFilter = true;

}

// filter tree leaves

if (current.Children.Count > 0)

{

foreach (var item in current.Children)

{

queue.Enqueue(item);

}

foreach (var root in _persons)

{

Items.EditItem(root);

Items.CommitEdit();

refreshFilterStatus(root, root.Children);

}

private void refreshFilterStatus(Person parent, IEnumerable<Person> items)

{

foreach (var item in items)

{

parent.FilteredChildren.EditItem(item);

parent.FilteredChildren.CommitEdit();

}

foreach (var item in items)

{

refreshFilterStatus(item, item.Children);

}

private void setParentFilterStatus(Person person)

{

Person currentPerson = person;

while (currentPerson.Parent != null)

{

currentPerson.Parent.IsRemovedByFilter = false;

//// if a filter is applied, expand parent's nodes

//if (!string.IsNullOrEmpty(FilterText))

// currentPerson.Parent.IsExpanded = true;

currentPerson = currentPerson.Parent;

}

public class Person : ViewModelBase

{

public string Name { get; set; }

public bool IsRemovedByFilter { get; set; }

public Person Parent { get; private set; }

public ObservableCollection<Person> Children { get; private set; }

public ListCollectionView FilteredChildren { get; private set; }

public Person(Person parent)

{

Children = new ObservableCollection<Person>();

FilteredChildren = new ListCollectionView(Children);

}

Run the example, and type the letter z. The filtering is fast. Delete the z, it now took a little more time.

Repeat this procedure few more times. You should notice that it becomes slower and slower each time (my guess would be event handlers leaking, but I didn't confirm it).

With dotTrace I can see that when the first z was typed, OnSourceViewColelctionChanged was called 5150 times.

The the z was deleted, OnSourceViewColelctionChanged was called 15150 times.

After repeating it 5 more times, OnSourceViewColelctionChanged was called 105150 times when the z was typed, and 115150 times when the z was deleted.

Currently, it is much faster (also due to virtualization) to just refresh the entire ListCollectionView

TreeListView

answered on 26 Aug 2016

14 answers

257 views

Partially different build numbers

Hi!

I just installed the latest release of UI for WPF (Q1 2016) via control panel. What I noticed is that most of the installed assemblies are compiled on 01/12/2016, however some of them are compiled on 01/06/2016. This also means that the assemblies have different product versions.

Example (from Binaries.NoXaml/WPF45): Telerik.Windows.Control.dll (2016.1.112.45), Telerik.Windows.Documents.Core.dll (2016.1.106.45).

This never happened before, all files of a release normally had the same build date. Since I build my projects using special target files including the version number of each assembly this is very annoying. Please correct this in the next build.

Regards
Heiko

Installer and Visual Studio Extensions

answered on 26 Aug 2016

1 answer

342 views

Defer Filtering on RadGridView

Hello.

I have a WPF MVVM application with several screens with grids. I currently use FilteringMode="FilterRow" on these grids. The problem I'm having is that after each filter is changed and loses focus, a database trip is made. This is very expensive and slow (going through OData and EF). I would like to defer all filtering until the user clicks a button. I can do this now by not binding a command to the Filtered event, but a change in filter still filters the grid page that currently has focus.

I have done some searching around and I do see that it's not possible to defer filtering when using FilterRow but I would like to explore what options I do have. Popup mode is not an option here as there's too much code to switch out. I saw Custom Filtering as an option but keep in mind that I have lots of grids each with lots of columns (my grid I'm testing with has 56 columns) and I have to be able to apply this across the board.

What I'm ultimately looking for is a way for a user to type their filters into whatever fields they choose and then click 1 button to apply all of them at once. The grid should not update at all when each field loses focus.

Any suggestions?

GridView

answered on 26 Aug 2016

1 answer

79 views

RadViewGantt : Custom each label inside segment

Hi,

I would like know it is possible to customize label inside each segment with a new property of our custom task.

What is the best way for that?

Thanks,

regards.

GanttView

answered on 26 Aug 2016

1 answer

227 views

Dealing with IsExpanded in large hierarchial RadGridView

I am running into issues with IsExpanded in our hierarchial RadGridView.

We have the IsExpanded property bound in a style, using the following statement:

<Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}" />

This works up until the GridView has enough items that it needs to scroll. If the user scrolls, the binding to IsExpanded gets messed up due to Virtualization.

So I set EnableRowVirtualization="False" on the grid and that fixed the problem.

HOWEVER, now when a user hits our "Expand All" button, it takes FOREVER to expand all of our rows, upwards of several minutes. With Row Virtualization, it took a few seconds. So clearly we can't do this.

How should I be attempting to do this? Is there a different way we should be handling IsExpanded that will allow us to work with Row Virtualization turned on? We are MVVM and I'd prefer to handle this in our ViewModel like we currently are, but I don't mind stuffing a few things into the code behind if it means fixing this problem.

Thank you for any direction you can give us on this issue.

GridView

answered on 26 Aug 2016