In.NET8 Microsoft has released databinding improvements: What's new in Windows Forms .NET 8 - Windows Forms .NET | Microsoft Learn. Add Command Binding and DataContext Support in .NET 8+
Hi, all. I am using the example you guys provide in your website and you can get from here: https://www.telerik.com/blogs/winforms-scaling-at-large-dpi-settings-is-it-even-possible-#example
As you can see in the image, I open the form in my main screen with Scale 100%. I have a second screen running in 150%. When I grab the form near to the left edge side of it, it resizes in one way, what I believe that is the correct way. However, if you grab the form near to right edge side, near the minimize, maximize and close button, it resizes differently. We have several users using our application and we are not able to fix this scalling issue, even in your own example. Could you guys have a look at it and prioritize? This kind of issue has been around for a long time without a final resolution. if not possible, let us know that we will have to decide move to another development tool.
Telerik version: 2024.2.514
When I use the new project wizard provided by Microsoft for a new windows forms project it lets me select the target .net version
When I do the same with the Telerik wizard, it does not let me choose what .net Version I'm targeting and does not generate the optimal code for the target version. For example when I target .net 9.0 with high dpi support, it should generate API calls for High DPI, not an entry in the app manifest. IMHO the generated code should be as close to the Microsoft Standard for the targeted .net version as possible.
This bug is about a mismatch between what behaviour is expected (on a functional level) and the actual behavior. There are different scenario's:
A normal example without a bug
int index = myRadGridView.Rows.Add(1, 2, 3); Actual and expected behavior
Adds a row to the grid, filling cells with the values 1, 2 and 3. Even when there are more columns than values, only the first 3 cells are filled.
Bug #1
int index = myRadGridView.Rows.Add(); // Will result in: myRadGridView.Rows.Add(new object[0]);Actual behavior
IndexOutOfRangeException is thrown.
Expected behavior
A new row is added, the cells are not filled with anything, since it should not matter if 3, 4 or zero values are added to the cells. Or, if you are very strict, an ArgumentOutOfRangeException, telling us at least 1 value is required.
Remark
Of course there is also a NewRow() method. But that is no reason Add() should not be allowed to accept zero values.
Bug #2
int index = myRadGridView.Rows.Add((object[])null);
Actual behavior
A NullReferenceException is thrown.
Expected behavior
ArgumentNullException, telling us that parameter "values" is not allowed to be null.
Bug #3
int index = myRadGridView.Rows.Add(new GridViewDataRowInfo(...), new GridViewDataRowInfo(...));
// or
int index = myRadGridView.Rows.Add(new object[] { new GridViewDataRowInfo(...), new GridViewDataRowInfo(...) });Actual behavior
Only the first row is added. The second row, or even the second value (integer, string, whatever) is totally ignored.
Expected behavior
- Or when a mixture of rows and values if given, an ArgumentException telling us that values and rows are not allowed to be mixed.
- Or when the values are all rows, all rows are added and the index of the last row is returned.
- Or an ArgumentException telling us that rows are not allowed to be added by this method and Add(GridViewDataRowInfo) or AddRange(GridViewDataRowInfo[]) are to be used.
Remark
The method Add(params object[] values) checks if the first value is a row, resulting in this and the previous bugs.
Repro-steps:
myRadGridView.Rows.Add((GridViewDataRowInfo)null);Actual behavior
- NullReferenceException is thrown
- A new row is added.
Excepted behavior
- Or an ArgumentNullException is thrown, and no rows are added.
- Or a new row is added, and no exception is thrown.
Remark
The method AddRange is also impacted by this bug.
Repro-steps
- Create a RadGridView
- Add a GridViewDecimalColumn
- Add a GridViewSummaryRowItem with a GridViewSummaryItem which:
- calculates the average of the values in the decimal column
- formats the value to two decimals after the decimal point: {0:0.00}
- Make an event handler for ViewCellFormatting.
- Add some rows with values to the grid.
- In the event handler, try to read ((GridSummaryCellElement)e.CellElement).Value.
Actual behavior
The value contains a string representing the formatted and rounded value of the average of all values.
Expected behavior
The value contains a raw, not rounded, not formatted, decimal value.
Remarks
I expect this behavior since GridSummaryCellElement has two properties: Text and Value.
I expect those to have difference functions. Value to hold the actual calculated value, and Text to hold the formatted, round string-equivalent.
Another reason why I expect this, is that Value is of type object, not of type string. So expect a value corresponding to the original datatype of the column and/or the result of the calculation.
Follow-up questions
- In what scenario may I expect in Value another data type that string?
- How, during the event handler, can I retrieve the original calculated value (with using parsing, since that is slow and does not contain all the digits).
Visual Studio 2022 crashes when working with a solution containing two WinForms projects:
- Project 1: WinForms (.NET 9) with Telerik
- Project 2: WinForms (.NET 6) without Telerik
Steps to Reproduce:
- Create a new solution in Visual Studio 2022.
- Add two WinForms projects:
- Project 1: WinForms (.NET 9) with Telerik
- Project 2: WinForms (.NET 6) without Telerik
- Open the WinForms designer for a form in Project 1 (Telerik, .NET 9).
- Without closing the designer, open the WinForms designer for a form in Project 2 (.NET 6, no Telerik).
- Switch to the code view of the form in Project 2.
- Switch back to the WinForms designer in Project 2.
Expected Result:
Visual Studio should smoothly switch between code and designer views without issues.
Actual Result:
Visual Studio freezes and crashes after switching back to the WinForms designer in Project 2.
Environment:
- Visual Studio 2022
- Windows Version: (Windows 11 x64)
- Telerik WinForms Version: (2025.1.211)
Additional Notes:
- The issue seems to be related to handling different .NET versions and Telerik components in the same solution.
- The crash occurs consistently when following the steps above.
- No explicit error messages are shown before Visual Studio closes.
When I show some text and set IsWordWrapEnabled to true... the horizontalscrollbar disappears
but when I set IsWordWrapEnabled to false after this, the horizontalscrollbar does not appear
in your code I saw this:
editor.SetValue(HorizontalScrollBarVisibilityProperty, newScrollVisibility);
But this .Auto property doesn't seem te work.
Further more, next to this problem, I'd like to set this horizontalscrollbar to appear and disappear depending on the text width...
but I'm afraid this would be depending on the .auto property
Since 2025 Q2 you'll get this error message when you try to open a flyout on a control that is not a Form. This does not happen with 2025 Q1.
Might be related: https://feedback.telerik.com/winforms/1688619-radform-clientsize-on-inherited-radform-is-broken
However, this time I have no patch / workaround. I have not the time to investigage deeper at the moment, so update to Q2 not possible for me at the moment.
It will be nice if one can add his custom sub menu items at design-time through the 'Add new item' menu. This was supported in the past, but the support was removed together with the introduced design-time optimizations.
Themes are applied partially to RadSpellChecker's forms.