Questions on UI for WinForms Forum

1 answer

131 views

When using EnableHeaderCheckBox, sorting the header columns does not work

I am using the EnableHeaderCheckBox to have a "Select All" checkbox in the header of my boolean column. I have the radgridview.EnableSorting = true and they work just fine, but when I click the "Select All" header checkbox and then try to sort any column, they do not sort at all. It does nothing. I am using Telerik UI for Winforms version 2017.2.502. Can someone please help?

GridView

answered on 10 May 2018

1 answer

146 views

An exception occurs when working with a font

I use the font property when working with RadPropertyGrid.

My user entered a font size of -1. An exception is thrown and the program falls.

For comparison in the PropertyGrid (WinForms), this situation is correctly handled.

PropertyGrid

answered on 09 May 2018

1 answer

288 views

Hide Item, Show Item?

I can hide a layout item using HideItem() method but then how do I make it visible again?

LayoutControl

answered on 09 May 2018

4 answers

2.9K+ views

cancel form close with FormClosing

I think I read how to do this but searching 'FormClosing' in this forum didn't find anything much.

I simply need to cancel the closing of a form (after user dialog confirmation). Is this the correct approach?

private void OnFormClosing(object sender, FormClosingEventArgs e)

{

var dlg = new DlgConfirmUnsavedForm();

var result = dlg.ShowDialog();

if (result == DialogResult.Cancel)

{

e.Cancel = true;

OnClosing(e);

return; //??

}

else if (result == DialogResult.Yes)

{

SaveForm();

}

...

}

By the way, post editing is terrible!

Form

answered on 09 May 2018

3 answers

154 views

[Solved] Excel Addin hangs when MCCB is scrolled

Hi,

I've a problem (again) when the MCCB is used in an Excel addin environment.

If the MCCB is used on a normal form (non modal) and you scroll (mouse wheel) inside the dropdown (grid) then the complete addin hangs.

If you do the same in an modal form, everything works fine.

Sample project is attached (rename to zip)

Steps to reproduce:

    button2 -> opens modal form (OK)
  button1 -> opens non modal form (not OK)
  open dropdown and then scroll inside grid with mouse wheel

Is there any workaround? (even if I have to disable mouse scrolling, would be better than an hanging application)

MultiColumn ComboBox

answered on 08 May 2018

5 answers

166 views

RadForm

Isn't there any way to add an extra button to the caption form like the help button without making the form border style (None)

General Discussions

answered on 08 May 2018

3 answers

117 views

[Solved] Running form as Dialog from Treeview DragEnded event stuck sometimes

I'm using two RadTreeView to Drag and Drop Nodes from Right to Left. When "Node 1" is Drag from Right and Drop to Left RadTreeView a Dialog is shown.
If I Drag and Drop other Node before "Node 1" the Dialog stuck and I cannot write on the TexBoxes.

How can I solve this issue?

Main Form

https://i.stack.imgur.com/Qf1QM.png

public partial class Main : RadForm

{

public Main()

{

InitializeComponent();

}

private void RightRadTreeView_DragEnded(object sender, RadTreeViewDragEventArgs e)

{

if (e.Node.Text == "Node 1")

{

new RadForm1().ShowDialog();

}

private void Form1_Load(object sender, EventArgs e)

{

//Right

this.RightRadTreeView.Nodes.Add(new RadTreeNode { Text = "Node 1" });

this.RightRadTreeView.Nodes.Add(new RadTreeNode { Text = "Node 2" });

this.RightRadTreeView.Nodes.Add(new RadTreeNode { Text = "Node 3" });

this.RightRadTreeView.Nodes.Add(new RadTreeNode { Text = "Node 4" });

}

Dialog Form

https://i.stack.imgur.com/hH7Ln.png

Treeview

answered on 08 May 2018

3 answers

279 views

[Solved] RadTreeView hangs after click

Hello there,

I have a telerik tree view with tens of thousands of nodes (around 190k). When I load this in most computers, it works ok, sometimes it takes a few seconds to open nodes, but that's acceptable for the number of nodes.

But, in some Windows 10 computers (not all of them), the tree takes more than 20 min to respond, if it ever does. This happens when clicking anywhere in the tree component (expand buttons, nodes, scrollbar...).

One of the computers details where it hangs is:

Windows 10 Enterprise (64 bit). Version 1703.
.NET 4.7.1
Telerik 2018.1.116.40
The laptop has a touch screen

After debugging I found the tree is stuck in GetChild() method (it loops through all the nodes, several times), from RadTreeViewAccessibleObject (attached call stack). This seems to come from windows messages.

Checking in computers where the tree doesn't hang, this call never happens, which makes me think it's a problem with the implementation of windows messages, in some specific version of windows + hardware.

Any ideas on how to fix or bypass this?

Treeview

answered on 07 May 2018

2 answers

125 views

[Solved] PageView Winforms

Isn't there any way to add an add (+) button to the pageview so that the user can add pages from the pageview itself

please help me with a code and a screenshot.

thanks In advance

General Discussions

answered on 07 May 2018

1 answer

526 views

Treeview binding to model

I have been populating my treeviews programmatically but would like to change to binding.

I read data from db and build a data model. I'd like to bind the data model to my treeview. so that when collections of objects and objects' properties themselves change they should automatically update in the treeview.

Which binding method would be the best way to achieve this? I've attached a simple mockup diagram to show the hierarchical structure. (Node types are abbreviated and I've removed the N level shown in the diagram from the code, as it doesn't really add to my question). The first part shows the model, and below shows some sample data.

I did a quick test like below which works, but doesn't allow for the collection of Table objects in Form (sibling to the Elements collection) to be populated. I hope this makes sense.

// pseudocode

class DataModel { public List<Form> forms; }

class Form { public string Name { get; set;} public List<Element> Elements; public List<Table> Tables; }

class Element { public string Name { get; set;} }

class Column { public string Name { get; set;} }

class Table { public string Name { get; set;} public List<Column> Columns; }

// not showing creation of data model; see diagram for structure

// var DataModel sampleData;

_view.DataSource = new BindingList<Form>(sampleData.forms);

_view.DisplayMember = "Name\\Name";

_view.ChildMember = "Forms\\Elements";

As a side question, I'd like to have the T objects and the F objects (for example) in their own visual 'folder' in the treeview. Can this be still achieved with data binding, or should I stick my manual population method (which has lots of overhead trying to keep data model and tree view in synch with events, etc.).

Treeview

answered on 07 May 2018