Copy a Cell throws an exception

Hi, Patrick,

I am really sorry to hear that you are experiencing any difficulties with the copy functionality in RadGridView. However, according to the stack trace it wouldn't be easy to determine what causes this undesired behavior. Could you please elaborate? Could you please specify the exact steps how to reproduce the problem? Alternatively, you can submit a support ticket from your Telerik account and provide a sample runnable project demonstrating the problem you are facing. Thus, we would be able to make an adequate analysis of the precise case and provide further assistance. Thank you.

OK, Patrick. Thank you for sharing this with the community. However, this error doesn't seem to be related directly to the RadGridView control from the Telerik UI for WinForms suite. When a Copy operation is performed, RadGridView internally uses Clipboard.SetDataObject(Object) method. In the different general programming forums, someone confirmed that if the SetDataObject(Object, Boolean) method overload is used, the error doesn't occur on his end. Could you please confirm whether this has a positive impact on your machine as well? I have prepared a sample code snippet for your reference demonstrating how to customize the copy behavior in RadGridView: 

        public class CustomGrid : RadGridView
        {
            public override string ThemeClassName
            {
                get
                {
                    return typeof(RadGridView).FullName;
                }
            }
            protected override RadGridViewElement CreateGridViewElement()
            {
                return new CustomRadGridViewElement();
            }
        }

        public class CustomRadGridViewElement : RadGridViewElement
        {
            protected override Type ThemeEffectiveType
            {
                get
                {
                    return typeof(RadGridViewElement);
                }
            }
            protected override MasterGridViewTemplate CreateTemplate()
            {
                return new CustomMasterGridViewTemplate();
            }
        }

        public class CustomMasterGridViewTemplate : MasterGridViewTemplate
        {
            public override void Copy()
            {
                MethodInfo mi = typeof(MasterGridViewTemplate).GetMethod("CopyContent", BindingFlags.Instance | BindingFlags.NonPublic);
                object copyResult = mi.Invoke(this, new object[] { false });
                Clipboard.SetDataObject(copyResult, true);
            } 
        }

Hi Dess,

I had a chance today to try your suggested code, and it immediately resolved the issue. No longer any exceptions are thrown when I try to copy values from columns of any datatype in RadGridView while running in Visual Studio debug mode.

Thank you for going beyond the expected and helping out your customers and the community. You're wonderful!

Last week I upgraded our code to .Net Framework 4.8.2 from 4.5.2 and started getting a new Exception 

System.Reflection.TargetParameterCountException
  HResult=0x8002000E
  Message=Parameter count mismatch.
  Source=mscorlib
  StackTrace:
   at System.Reflection.RuntimeMethodInfo.InvokeArgumentsCheck(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

This is thrown by this line 

object copyResult = mi.Invoke(this, new object[] { false });

in CustomMasterGridViewTemplate.Copy(). I resolved it by pure luck, by trying to add more parameters.

object copyResult = mi.Invoke(this, new object[] { false, false });

Hi, Patrick,

I am sorry to hear that you are experiencing any difficulties with RadGridView.

Note that all UI controls are not thread safe controls in the whole Windows Forms platform (not just Telerik controls, but all controls out there). Here is an article on MSDN, describing how to make thread-safe Winforms UI application. This means that any control from the Telerik UI for WinForms suite is not thread safe as well and cannot be used outside the main UI thread. You should use an Invoke to update the controls in cross threading scenario.

Usually, such an error is possible to occur when the invoked method doesn't get all the parameters passed:

private DataObject CopyContent(bool cut, bool copyToClipboard = true) 

The following MSDN thread discusses a similar topic as well:  https://social.msdn.microsoft.com/Forums/vstudio/en-US/dc142c3e-05a6-4862-8f2d-22f4dc504c11/how-to-resolve-the-exception-quotparameter-count-mismatchquot-is-thrown-from?forum=csharpgeneral