I just upgraded to the latest version of Telerik products and facing the issues described below.

When dragging and drop Telerik UI objects from the toolbar on a form, the dialog box below is displayed with question but there is no button to click to answer the question and I don't where to stop it.

See screenshot attached.

Hi All,

Note:- I am using Bound RadTreeview. Bound with DataSource.

1 Take RadTreeview

2 Add Few nodes Like:

    ......Node A

    ......Node B

    ......Node C

    ............Node D

    ............Node E

3 Now Drag Node B and Drop it in Node C (As Node C's Child)

4 It throw Exception Error Msg  "Collection was modified; enumeration operation may not execute."

5  Now Try to Drag Node E and Drop it in Node B, again same error occurs

6 Full error screen i attached here.

Please reply as soon as possible.

Hello Guys,

Good Evening , As per your suggestions i make my custom treeview node with LiteVisualElements .

In That Node i have taken one StackLayoutElement and RoundRectShape assigned to it but still panel shows corners instead of round edges,

i tried with different properties and styles but not get succeed , so please help me out.

here i have attached image of my node and "stackLayoutElement" code too.

Zooming in will throw an Exception that crashes the program.

The ZoomLevel needed to cause the exception is dependent on the area of the RadMap selected.

Provider: BingRestMapProvider

ImagerySet AerialWithLabelsOnDemand

Zooming in over Antarctica, Exception thrown zooming in at MapElement.ZoomLevel 14.

Zooming in over Australia, Exception thrown zooming in at MapElement.ZoomLevel 21.

Hi,

I want to hide some columns of the table I received from Excel on RadGridView.

Hi everybody

I m try use the class CustomDragandDrop on radtreeview but i have a issue, 

if i use the next example, i dont have any problem:

   protected void BindRadTreeView()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("Id", typeof(string));
            dt.Columns.Add("Title", typeof(string));
            dt.Columns.Add("ParentId", typeof(string));

            string parentId = string.Empty;
            string childId = string.Empty;
            for (int i = 0; i < 2; i++)
            {
                parentId = Guid.NewGuid().ToString();
                dt.Rows.Add(parentId, "Node" + i, null);
                for (int j = 0; j < 5; j++)
                {
                    childId = Guid.NewGuid().ToString();
                    dt.Rows.Add(childId, "SubNode" + i + "." + j, parentId);
                }
            }

            this.radTreeView1.ChildMember = "Id";
            this.radTreeView1.ParentMember = "ParentId";
            this.radTreeView1.DisplayMember = "Title";
            this.radTreeView1.DataSource = dt;


        }

i can drag and drop correctly

but the problem is when i binding the Radtreeview

    protected void llenatreeview1() {

            dtTablas = dat.consultaBD();

            DataTable dt = new DataTable();
            dtCopi.Columns.Add("Id", typeof(string));
            dtCopi.Columns.Add("Title", typeof(string));
            dtCopi.Columns.Add("ParentId", typeof(string));

            string parentId = string.Empty;
            string Id = string.Empty;
            string title = string.Empty;
            foreach (DataRow row in dtTablas.Rows)
            {
                parentId = row["ParentId"].ToString();     

                Id = row["Id"].ToString();
                title = row["Title"].ToString();

                if (parentId == "")
                    dt.Rows.Add(Id, title, null);
                else
                    dt.Rows.Add(Id, title, parentId);
            }

            radTreeView2.ChildMember = "Id";
            radTreeView2.ParentMember = "ParentId";
            radTreeView2.DisplayMember = "Title";
            radTreeView2.DataSource = dt;
        }

first is freeze and then appears the error.

when i drag and drop appears then next error:

System.StackOverflowException

what am I doing wrong please your help. thanks

GridView has a default text alignment for new columns as 'MiddleCenter'.

Default alignment for new GridViewDataRowInfo is 'left'.

Please can these be the same ?

Hi there,

We have recently found a bug on both the RadDocument and Rad Rich Text Editor. Created a RTF document via the RadRichText Editor. The RTF document contains a table. When the document is saved and loaded from the same form, it is displaying correctly, however when loaded from a different form, it seems to have shrunk and lost the column width, thus having long and skinny columns.

We have set the fixed column width on the table, however this did not seem to solve the issue.

I have attached two screenshots for reference. One with the correct looking table, and one with the long and skinny columns.

Is there a workaround, or is this a known bug?

Correct table:

Long and skinny columns:

Currently on Telerik Winforms version 2018.3.1016.40

Kind regards,

Paul

I have a form which contains TreeView control. I need to convert it to RadTreeView. So I replaced TreeView control with RadTreeView and TreeNode with RadTreeNode in the code. I found that the events in both are different, so tried to replace the events with similar events in RadTree.

Following are the events that I have replaced in my code :

1.  

        Private Sub TreeView1_AfterExpand(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles tvMain.AfterExpand

Replaced by -

        Private Sub TreeView1_AfterExpand(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.RadTreeViewEventArgs) Handles tvMain.NodeExpandedChanged   

2.

            Private Sub TreeView1_AfterCollapse(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles tvMain.AfterCollapse

  Replaced by -  

            Private Sub TreeView1_AfterCollapse(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.RadTreeViewEventArgs) Handles tvMain.NodeExpandedChanged

and included Expanded flag to check if it is expand or collapse.

Here, I noticed unwanted firing of this replaced event when compared to the old event, but I handled it using the Expanded flag.

3.

        Private Sub tvMain_AfterSelect(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles tvMain.AfterSelect

Replaced by -

        Private Sub tvMain_AfterSelect(ByVal sender As System.Object, ByVal e As Telerik.WinControls.UI.RadTreeViewEventArgs) Handles tvMain.SelectedNodesChanged

This event gets fired twice while clicking on a node.

My main issues are,

• During the initial load of the form, the tree gets populated and at that time the select event (mentioned in point 3) fires automatically in my old project in which TreeView is used. But in the new project, during the load of the form the replaced event is not fired.
• Similarly, when I clicks a node , the replaced select event fires twice. After that I have a button in the same form which works like, when we click on a node and then click on the add button it will add a new node to the tree under the selected node. Now the functionality of the button doesnt work because, within the click function of add button, treeView1.selectedNode is 'Nothing'. Eventhough the select event is fired on clicking the node, the selectednode is 'Nothing' inside the click function of add button.

See attached screenshot. The popup calendar looks wrong when running on a display with 250% scaling. Surely, that's not correct. The calendar should not be so large and the fonts so small. Am I missing something? I have done all the other steps to enable High DPI support, and as you can see, the textbox area seems to scale fine.

Any ideas?

David

1. Select the ColorBox's ellipses to open the Color Dialog

2. Select the Web tab

3. Select Any colour in this Page

4. Select Transparent

Colour will update

5. Select the Professional tab

6. Select any colour

Colour won't update

7. Select any colour

Colour won't update

8. Select OK on Dialog

Colour will be transparent

Values will be same as selected in step 7

I would like to have a generic validation-mechanism, implemented in all controls. Hear me out:

A class ValidationInformation for containing all sort of validation information for a certain field, property, cell, etc. which has properties likes:

• Type DataType
• object MinValue
• object MaxValue
• int? MinLength
• int? MaxLength
• bool IsRequired
• RegEx Mask
• etc.

It also has a virtual method like bool Validate(object entity, object value, out string validationError).

A base class ValidationInformationProvider for retrieving validation information from various sources. It has some abstract methods for retrieval, storing/caching information per cell/field/property.

This base class has the following subclasses:

• ValidationInformationProviderFromDataTable
• ValidationInformationProviderFromAnnotations
• ValidationInformationProviderFromXXX

Each provider is responsible for reading validation information from the source (DataTable, annotations on a property, etc.) and fill a ValidationInformation object.

Now the fun begins...

Each Telerik class, like RadGridView and/or subcomponents should get a method or event to retrieve ValidationInformation. When the event is not handled or the method returns null, the default behavior kicks in.

When ValidationInformation is provided, default behavior is overridden. Properties of editors van be set with values from ValidationInformation (like Minimum and Maximum of a GridViewDecimalColumnPlus or RadSpinEditorElement). At the end if editing the method ValidationInformation.Validate is called to validate the new value. The validation error can be used for popups, or tooltips, or an exception. 

This way a user does not have to think where to set which property of any Telerik control for any validation. This way a RadPropertyGrid and RadGridView can work the same way when it comes to data validation, regardless of all editors which work in the background. 

In the image below you can notice lines that disappear, identical lines but rendered more or less thick.

Hi Dinko and Team,

As I mentioned in the previous forum, We need fix for Raddropdownlist.SelectedIndex.

When we set SelectedIndex=5 or some value in selectedIndexchangedEvent then the recursive call is happening for SelectedIndex. So we need to restrict the recursive call for both Raddropdownlist.DataSource as well as Raddropdownlist.SelectedIdex.

  private void radDropDownList1_SelectedIndexChanged(object sender, Telerik.WinControls.UI.Data.PositionChangedEventArgs e)
        {
           fillIndustryProcess1(); // radDropDownList1.DataSource = dt; when we set Datasource the recursive call is occurring
            radDropDownList1.SelectedIdex = 5; // radDropDownList1.SelectedIdex= 5; when we set Datasource the recursive call is occurring

}

Old Forums in which , Telerik team fixed the RadDropDownList .SelectedValue.

Telerick version 2023.1.314 RadDropDownList controls throwing StackoverflowException when migrating visual studio 2010 to 2022 in UI for WinForms | Telerik Forums 

Previous forums in which , Telerik team yet to fix for RadDropDownList.Datasource.

Telerick version 2024.1.130.48, RadDropDownList controls throwing StackoverflowException when migrating visual studio 2010 to 2022 in UI for WinForms | Telerik Forums

Thanks,

Maheswari

Hello support,

here is what happend:

I created a RadFrom with controlls on it.

Then i add it to my RadDock like this:

private void Add_RadForm_asDocument_ToRadDock(RadDock rd, HostWindow hw, object radform, string title)
{
    bool found = false;

    foreach (var item in radDock_main_notr.DockWindows)
    {
        if (item.GetType() == typeof(HostWindow))
        {
            if (((HostWindow)item).Name == radform.GetType().Name + "1")
            {
                found = true;
                hw = (HostWindow)item;
            }
        }
    }

    if (found == false && radform != null)
    {
        if (hw == null || hw.Text == "")
        {
            hw = rd.DockControl((System.Windows.Forms.Control)radform, DockPosition.Fill, DockType.Document);
        }
    }

    hw.Text = title;
    hw.CloseAction = DockWindowCloseAction.Close;
    hw.ToolCaptionButtons = ToolStripCaptionButtons.None;
    hw.Select();
}

The RadFrom is added to the RadDock:

Settings is the new RadFrom thats now docked.
But when i try to use the RadDropDownList then its "stucks" (also the other GUI controls):

The  changed selection of the RadDropDownList will not change.
When i close the RadForm via the "x" and eropen it again it works.

We work with a RadGridView with 145000 rows and 4 columns. We use copy-paste to move data around from other apps and the application with build with Telerik.

When we copy a flat file (with tabs delimited fields) and we paste it to the RadGridView, the whole process is painfully slow. The function to retrieve the data from the clipboard takes minutes (maybe hours, I cancelled it). It tracked the cause down to the StringTokenizer class. The tokenizer splits the string up into separate fields. But after extracting a field it creates a new copy of that string (containing about 10MB of data) minus the field. I patched it (with HarmonyX) and now it takes only one second:

static class StringTokenizerPerformancePatch
{
	static private readonly InstanceFieldAccessor<StringTokenizer, LinkedList<string>> _tokens = new InstanceFieldAccessor< StringTokenizer, LinkedList<string>>("tokens");
	static private readonly InstanceFieldAccessor<StringTokenizer, string> _sourceString = new InstanceFieldAccessor<StringTokenizer, string>("sourceString");
	static private readonly InstanceFieldAccessor< StringTokenizer, string> _delimiter = new InstanceFieldAccessor<StringTokenizer, string>("delimiter");
	static private readonly InstanceFieldAccessor< StringTokenizer, IEnumerator<string>> _enumerator = new InstanceFieldAccessor<StringTokenizer, IEnumerator<string>>("enumerator");

	[HarmonyPatch(typeof(StringTokenizer), "Tokenize")]
	staticclassPatch_StringTokenizer_Tokenize
	{
		static bool Prefix(StringTokenizer __instance)
		{
			var tokens = _tokens.GetValue(__instance);
			var sourceString = _sourceString.GetValue(__instance);
			var delimiter = _delimiter.GetValue(__instance);
			Tokenize(tokens, sourceString, delimiter);
			_enumerator.SetValue(__instance, tokens.GetEnumerator());
			returnfalse;
		}

		static private void Tokenize(LinkedList<string> tokens, string text, string delimiter)
		{
			tokens.Clear();
			
			if (string.IsNullOrEmpty(text))
				return;

			int index = 0;
			while(true)
			{
				var index2 = text.IndexOf(delimiter, index, StringComparison.Ordinal);
				if (index2 < 0)
				{
					tokens.AddLast(text.Substring(index));
					break;
				}

				string token = text.Substring(index, index2 - index);
				tokens.AddLast(token);
				index = index2 + delimiter.Length;
			}
		}
	}
}

• If delimiters are one character, why not use String.Split?
• Why use a LinkedList?