This is reproducible when you disable the automation peers by setting the AutomationManager.AutomationMode static property to Disabled.
It happens when you open a new RadWindow dialog (using the ShowDialog method), and the close it. After this, when you interact with the main window (click a button, hover a GridView, etc.) the exception occurs.
The exception is thrown only in the Output pane of Visual Studio and it doesn't cause any harm to the application. You can safely ignore it.
The exception message is "Invalid window handle".
To work this around you can enable the "Enable Just My Code" option in Visual Studio.
Currently, to modify the default appearance of the cells you can use the CellDecorationsNeeded event of RadVirtualGrid. The event args exposes a predefined set of properties that can be applied onto the cell. However, there is no text alignment.
Introduce a cell text alignment property in the event args similar to the CellTextAlignment of the RadVirtualGrid itself.
Select an item with mouse, scroll thousands of items down and then shift select item to perform range selection. This will block the UI thread for seconds.
To reproduce this use the following code snippet:
Steps to reproduce:
1. Start a new connection from Shape 1, by dragging one of its connectors.
2. Drag the connection over Shape 2.
Expected: The connector closest to the mouse should get highlighted and when you drop the connection it should get attached to the shape.
Actual: The closest connector is not highlighted. Also, when you drop the connection over the target shape it doesn't get attached.
If set the AutoCompleteMode property in a Style Setter, and exception is thrown.
To work this around set the property directly on the control.
<telerik:RadMultiColumnComboBox AutoCompleteMode="Search" />
Most commonly the exception message is "Input file or data stream does not conform to the expected file format specification".
This appears because of the glyphs font used in the different controls.
To work this around you can use two approaches:
Moving a window fast on low performance machine or between two monitors causes incorrect offset to be applied to the mouse cursor
Multi-byte Unicode characters can be represented as multiple ANSI characters in the form \'xx, for example:
\'89\'ce can represent the character 火 if multi-byte encoding should be used. Using multi-byte encoding could be set explicitly using the \ucN tag, or implicitly using the \fcharset for the current font (e.g. \fcharset134 is double-byte).
When such text is imported (commonly CJK text [Chinese, Korean, Japanese] the characters are imported incorrectly (as two '?' or as two different characters for each character)
Such RTF documents are produced from Office 2010 (Word, Outlook), WordPad - on saving or on copying content from the applications.
The ImagesDeflaterCompressionLevel and ContentsDeflaterCompressionLevel in the PdfFormatProvider's export settings have 0 for default value instead of -1. Workaround: Change the settings's properties to -1 explicitly.