Questions on UI for WinForms Forum

0 answers

20 views

2025 Q2 Upcoming distribution changes in Telerik UI for WinForms

As of 2025 Q2, CHM and Help3 offline documentation resources will be discontinued. The Telerik UI for WinForms offline documentation will be available to download as a PDF file from your Telerik account: Download Product Files

General Discussions

asked on 22 Nov 2024

2 answers

11 views

Issues when trying to export a page from RadPdfViewer directly to a Bitmap, without saving the file to the computer.

I have this code, and I just want to export all pages or a specific page from the loaded PDF in the RadPdfViewer, without saving the file to the computer.

The function RadPdfViewer.ExportPage returns a Bitmap, but when I assign the result of this function to a new variable of type Bitmap, an error occurs.

'1º Option - Work
For i As Integer = 1 To RadPdfViewer1.Document.Pages.Count
Dim guid As Guid = Guid.NewGuid

RadPdfViewer1.ExportPage(i, "C:\temp\" & guid.ToString() & ".pdf", 1, True, ImageFormat.Png)

Dim bitmap As Bitmap = New Bitmap("C:\temp\" & guid.ToString() & ".pdf")

Dim reader As BarcodeReader = New BarcodeReader With {
.AutoRotate = True,
.TryInverted = True
}

Dim result As Result = reader.Decode(bitmap)

If result Is Nothing Then Continue For

Dim decoded As String = result.ToString().Trim()

If decoded Is Nothing Then Continue For

If decoded <> TextBox1.Text Then TextBox1.Text = TextBox1.Text & vbNewLine & vbNewLine & decoded

bitmap.Dispose()
My.Computer.FileSystem.DeleteFile("C:\temp\" & guid.ToString() & ".pdf")
Next

'2 Option - Dont Work
Dim bitmap As Bitmap = RadPdfViewer1.ExportPage(1, 1, False, ImageFormat.Png)

'3º Option - Dont Work
For Each bitmap As Bitmap In RadPdfViewer1.ExportPages(1, False, ImageFormat.Bmp)
Dim reader As BarcodeReader = New BarcodeReader With {
.AutoRotate = True,
.TryInverted = True
}

Dim result As Result = reader.Decode(bitmap)

If result Is Nothing Then Continue For

Dim decoded As String = result.ToString().Trim()

If decoded Is Nothing Then Continue For

If decoded <> TextBox1.Text Then TextBox1.Text = TextBox1.Text & vbNewLine & vbNewLine & decoded
Next

Accessibility

Form

General Discussions

PdfViewer and PdfViewerNavigator

answered on 04 Dec 2024

0 answers

8 views

Tab positioning in RadRibbonBar (Positionnement de l'onglet dans la RadRibbonBar)

Hello,

RadRibbonBar avec le thème Fluent (RadRibbonBar with Fluent theme)

En ajoutant la commande pour faire disparaitre le menu, l'onglet se positionne au début.

(By adding the command to make the menu disappear, the tab is positioned at the beginning.)

CAST(THIS-OBJECT:RadRibbonBar:GetChildAt(0):GetChildAt(5), Telerik.WinControls.UI.RadApplicationMenuButtonElement):Visibility = Telerik.WinControls.ElementVisibility:Hidden.

Si je change de thème (Desert) l'onglet se positionne pas au début (comme sur le thème Fluent).

(If I change the theme (Desert), the tab is not positioned at the beginning (as on the Fluent theme).)

Best regards

RibbonBar

asked on 03 Dec 2024

1 answer

7 views

Item appears duplicated in the popup when selected Desert Theme

Hello,

How do i make the item appear only once in the popup when the theme is Desert?

1 - Without Theme

2 - Desert Theme

Code:

List<TecnicoServicoInfo> listaTecnicos = new List<TecnicoServicoInfo>();

TecnicoServicoInfo tec = new TecnicoServicoInfo();
tec.CdFuncionario = -1;
tec.DsFuncionario = " ";
TecnicoServicoInfo tec1 = new TecnicoServicoInfo();
tec1.CdFuncionario = 80;
tec1.DsFuncionario = "robsu";
TecnicoServicoInfo tec2 = new TecnicoServicoInfo();
tec2.CdFuncionario = 1558;
tec2.DsFuncionario = "joelssu";
TecnicoServicoInfo tec4 = new TecnicoServicoInfo();
tec4.CdFuncionario = 333;
tec4.DsFuncionario = "TESTE UM NOME MAIOR QUE TODOS OS OUTROS PARA VER O TEMA";
listaTecnicos.Add(tec);
listaTecnicos.Add(tec2);
listaTecnicos.Add(tec1);
listaTecnicos.Add(tec4);
listaTecnicos = listaTecnicos.OrderBy(x => x.DsFuncionario).ToList();

ddlTecnico.DropDownStyle = RadDropDownStyle.DropDown;
ddlTecnico.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
ddlTecnico.DropDownListElement.AutoCompleteSuggest.SuggestMode = SuggestMode.Contains;
ddlTecnico.Items.Clear();

ddlTecnico.DescriptionTextMember = "DsFuncionario";
ddlTecnico.ValueMember = "CdFuncionario";
ddlTecnico.DisplayMember = "DsFuncionario";

ddlTecnico.DataSource = listaTecnicos;

ddlproxima.DropDownStyle = RadDropDownStyle.DropDown;
ddlproxima.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
ddlproxima.DropDownListElement.AutoCompleteSuggest.SuggestMode = SuggestMode.Contains;
ddlproxima.Items.Clear();

ddlproxima.DescriptionTextMember = "DsFuncionario";
ddlproxima.ValueMember = "CdFuncionario";
ddlproxima.DisplayMember = "DsFuncionario";

ddlproxima.DataSource = listaTecnicos;

ddlproxima.AutoSizeItems = false;
ddlproxima.AutoSize = false;

Telerik version: 23.2.718

Thank You!

DropDownList

Themes and Visual Style Builder

answered on 03 Dec 2024

2 answers

10 views

DropDown Dynamic loadDate

I had a question about the Dropdown element, I saw how to search for it, but I couldn't find it for dynamic
    public SearchWarehouseNP()
    {
        InitializeComponent();
        dropdownSettlement.DropDownStyle = RadDropDownStyle.DropDown;
        dropdownSettlement.AutoCompleteMode = AutoCompleteMode.Suggest;

        dropdownSettlement.DropDownListElement.AutoCompleteSuggest = new CustomAutoCompleteSuggestHelperUpdate(
            dropdownSettlement.DropDownListElement,
            async query =>
            {
                if (string.IsNullOrWhiteSpace(query) || query.Length < 3)
                    return Enumerable.Empty<DescriptionTextListDataItem>();

                var response = await _searchSettlementService.GetCityData(query);
                if (response.success && response.data.Any())
                {
                    return response.data.First().Addresses.Select(a => new DescriptionTextListDataItem
                    {
                        Text = $"{a.MainDescription} ({a.Area})",
                        Value = a.MainDescription,
                        DescriptionText = a.Area
                    });
                }

                return Enumerable.Empty<DescriptionTextListDataItem>();
            }
        );

        dropdownSettlement.SelectedIndexChanged += (s, e) =>
        {
            if (dropdownSettlement.SelectedItem is DescriptionTextListDataItem selectedItem)
            {
                Console.WriteLine($"Выбрано: {selectedItem.Text} ({selectedItem.Value})");
            }
        };
    }
}
The problem is that the data is not stored in Items

Console.WriteLine empty


using Telerik.WinControls.UI;

namespace NovaPostOrderManager.Helpers;

public class CustomAutoCompleteSuggestHelperUpdate : AutoCompleteSuggestHelper
{
    private readonly Func<string, Task<IEnumerable<DescriptionTextListDataItem>>> _fetchDataAsync;
    private CancellationTokenSource _cts = new();

    public CustomAutoCompleteSuggestHelperUpdate(RadDropDownListElement owner, Func<string, Task<IEnumerable<DescriptionTextListDataItem>>> fetchDataAsync)
        : base(owner)
    {
        _fetchDataAsync = fetchDataAsync;
    }

    protected override async void SyncItemsCore()
    {
        // Текущий текст из поля ввода
        string currentInput = Filter;

        // Проверяем, нужно ли загружать данные
        if (string.IsNullOrWhiteSpace(currentInput) || currentInput.Length < 3)
        {
            DropDownList.ListElement.Items.Clear();
            DropDownList.ClosePopup();
            return;
        }

        // Отменяем предыдущий запрос
        _cts.Cancel();
        _cts = new CancellationTokenSource();

        try
        {
            // Задержка перед началом запроса
            await Task.Delay(300, _cts.Token);

            // Загружаем данные
            var items = await _fetchDataAsync(currentInput);

            _cts.Token.ThrowIfCancellationRequested();

            DropDownList.ListElement.BeginUpdate();
            DropDownList.ListElement.Items.Clear();

            // Добавляем элементы в выпадающий список
            foreach (var item in items)
            {
                DropDownList.ListElement.Items.Add(item);
            }

            DropDownList.ListElement.EndUpdate();

            if (DropDownList.ListElement.Items.Count > 0)
            {
                DropDownList.ShowPopup(); // Показываем список, если есть элементы
            }
            else
            {
                DropDownList.ClosePopup();
            }
        }
        catch (TaskCanceledException)
        {
            // Запрос был отменён — игнорируем
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Ошибка загрузки данных: {ex.Message}");
        }
    }

    protected override bool DefaultFilter(RadListDataItem item)
    {
        if (item is not DescriptionTextListDataItem descriptionItem)
            return base.DefaultFilter(item);

        return descriptionItem.Text.Contains(Filter, StringComparison.CurrentCultureIgnoreCase) ||
               descriptionItem.DescriptionText.Contains(Filter, StringComparison.CurrentCultureIgnoreCase);
    }
}

DropDownList

answered on 29 Nov 2024

1 answer

24 views

Layout change color

The problem is that the data is not stored in Items

using Telerik.WinControls.UI;

namespace NovaPostOrderManager.Helpers;

public class CustomAutoCompleteSuggestHelperUpdate : AutoCompleteSuggestHelper
{
private readonly Func<string, Task<IEnumerable<DescriptionTextListDataItem>>> _fetchDataAsync;
private CancellationTokenSource _cts = new();

public CustomAutoCompleteSuggestHelperUpdate(RadDropDownListElement owner, Func<string, Task<IEnumerable<DescriptionTextListDataItem>>> fetchDataAsync)
: base(owner)
{
_fetchDataAsync = fetchDataAsync;
}

protected override async void SyncItemsCore()
{
// Текущий текст из поля ввода
string currentInput = Filter;

// Проверяем, нужно ли загружать данные
if (string.IsNullOrWhiteSpace(currentInput) || currentInput.Length < 3)
{
DropDownList.ListElement.Items.Clear();
DropDownList.ClosePopup();
return;
}

// Отменяем предыдущий запрос
_cts.Cancel();
_cts = new CancellationTokenSource();

try
{
// Задержка перед началом запроса
await Task.Delay(300, _cts.Token);

// Загружаем данные
var items = await _fetchDataAsync(currentInput);

_cts.Token.ThrowIfCancellationRequested();

DropDownList.ListElement.BeginUpdate();
DropDownList.ListElement.Items.Clear();

// Добавляем элементы в выпадающий список
foreach (var item in items)
{
DropDownList.ListElement.Items.Add(item);
}

DropDownList.ListElement.EndUpdate();

if (DropDownList.ListElement.Items.Count > 0)
{
DropDownList.ShowPopup(); // Показываем список, если есть элементы
}
else
{
DropDownList.ClosePopup();
}
}
catch (TaskCanceledException)
{
// Запрос был отменён — игнорируем
}
catch (Exception ex)
{
Console.WriteLine($"Ошибка загрузки данных: {ex.Message}");
}
}

protected override bool DefaultFilter(RadListDataItem item)
{
if (item is not DescriptionTextListDataItem descriptionItem)
return base.DefaultFilter(item);

return descriptionItem.Text.Contains(Filter, StringComparison.CurrentCultureIgnoreCase) ||
descriptionItem.DescriptionText.Contains(Filter, StringComparison.CurrentCultureIgnoreCase);
}
}

LayoutControl

updated question on 29 Nov 2024

1 answer

11 views

CheckedListBox in PropertyGrid

Hello Support Team.

I have an application with a PropertyGrid in C# with WinForms. Is it possible to have a CheckedListBox to allow multiple selections in the PropertyGrid?

Thank you in advance.

PropertyGrid

answered on 28 Nov 2024

1 answer

11 views

Editable DropDown list in PropertyGrid with a not-listed value

Hello, support team.

I have an application with a PropertyGrid in C# with WinForms. In this PropertyGrid I need to display a drop-down list with a predefined value list, but I need to allow also the user be able to edit a not listed value.

Thank you in advance

PropertyGrid

answered on 28 Nov 2024

1 answer

21 views

Remove LegendItem black border from RadMap (WinFroms)

I've tried to remove the black border around legenditems in RadMap to no avail. I've also tried to change the border colour to white and that has not worked. I was able to change the element spacing using .ElementSpacing = 0 but have not been able to remove the item borders. I've pasted the code below, how can I remove the black border around legend items? I'm using .Net Framework 4.8 Winforms.

Thanks

For Each dColor As Double In {0, 0.25, 0.5, 0.75, 1}.Reverse()
Dim oLegendItem As New MapLegendItemElement("", Color.White)

oLegendItem.EnableBorderHighlight = False
oLegendItem.BorderWidth = 0 ' Remove black outline?
oLegendItem.Margin = New Padding(0)
oLegendItem.Padding = New Padding(0)
oLegendItem.MinSize = New Size(20, 10)
oLegendItem.HorizontalLineWidth = 0
oLegendItem.BorderBottomColor = Color.White
oLegendItem.BorderTopColor = Color.White
oLegendItem.BorderTopWidth = 0
oLegendItem.BorderBottomWidth = 0
oLegendItem.DrawBorder = False

oLegendItem.BackColor = Color.White
oLegendItem.BackColor2 = Color.White
oLegendItem.BackColor3 = Color.White
oLegendItem.BackColor4 = Color.White
oLegendItem.BorderBottomShadowColor = Color.White
oLegendItem.BorderColor = Color.White
oLegendItem.BorderColor2 = Color.White
oLegendItem.BorderColor3 = Color.White
oLegendItem.BorderColor4 = Color.White
oLegendItem.BorderInnerColor = Color.White
oLegendItem.BorderInnerColor2 = Color.White
oLegendItem.BorderInnerColor3 = Color.White
oLegendItem.BorderInnerColor4 = Color.White
oLegendItem.ShadowColor = Color.White
oLegendItem.BorderInnerColor4 = Color.White

oLegendItem.BorderThickness = New Padding(10)
oLegendItem.BorderHighlightThickness = 0
oLegendItem.DrawFill = False

.ItemStackElement.Children.Add(oLegendItem)
Next

With .ItemStackElement
.BackColor = Color.White
.BackColor2 = Color.White
.BackColor3 = Color.White
.BackColor4 = Color.White
.BorderBottomShadowColor = Color.White
.BorderColor = Color.White
.BorderColor2 = Color.White
.BorderColor3 = Color.White
.BorderColor4 = Color.White
.BorderInnerColor = Color.White
.BorderInnerColor2 = Color.White
.BorderInnerColor3 = Color.White
.BorderInnerColor4 = Color.White
.ShadowColor = Color.White
.BorderInnerColor4 = Color.White

.ElementSpacing = 0 ' Remove spacing
.EnableElementShadow = False

.DrawBorder = False
.EnableFocusBorder = False
.BorderColor = Color.White
.BorderBottomColor = Color.White
.BorderWidth = 0
.EnableBorderHighlight = False
.DrawBorder = False
.BorderBottomWidth = 0
.BorderBottomWidth = 0
.BorderThickness = New Padding(0)
.BorderHighlightThickness = 0
End With
End With