Getting an error with TextRange method for unclear reason
Im trying to highlight a TextRange in a richtextbox in wpf, However I keep getting the error below about an invalid argument, even though I am quite confident the argument is infact correct. I understand how to stop the program from crashing but if this ArgumentException is thrown then my program does not do what I wish it to.
The code is below for the GetAllWordRanges Method.
private static IEnumerable<TextRange> GetAllWordRanges(FlowDocument document, List<string> keywords)
{
foreach (string keyword in keywords)
{
TextPointer pointer = document.ContentStart;
while (pointer != null)
{
if (pointer.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.Text)
{
string textRun = pointer.GetTextInRun(LogicalDirection.Forward);
MatchCollection matches = Regex.Matches(textRun, keyword);
foreach (Match match in matches)
{
int startIndex = match.Index;
int length = match.Length;
TextPointer start = pointer.GetPositionAtOffset(startIndex);
TextPointer end = start.GetPositionAtOffset(length);
yield return new TextRange(start, end);
}
}
pointer = pointer.GetNextContextPosition(LogicalDirection.Forward);
}
}
}
Exception Detail:
System.ArgumentException was unhandled
HResult=-2147024809
Message='SolidBrush' parameter type is not valid for formatting property 'Background'.
Parameter name: value
Source=PresentationFramework
ParamName=value
StackTrace:
at System.Windows.Documents.TextRange.ApplyPropertyValue(DependencyProperty formattingProperty, Object value, Boolean applyToParagraphs, PropertyValueAction propertyValueAction)
at System.Windows.Documents.TextRange.ApplyPropertyValue(DependencyProperty formattingProperty, Object value)
at EmailCheckerWPF.TextAnalyser.turnTextRed(RichTextBox TextBox, List`1 Keywords) in c:\Users\Luke\Documents\Caimbridge comp\EmailCheckerWPF\TextAnalyser.cs:line 138
at EmailCheckerWPF.MainWindow.AnalyseButton_Click(Object sender, RoutedEventArgs e) in c:\Users\Luke\Documents\Caimbridge comp\EmailCheckerWPF\MainWindow.xaml.cs:line 50
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
at System.Windows.Controls.Primitives.ButtonBase.OnClick()
at System.Windows.Controls.Button.OnClick()
at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
at System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
at System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
at System.Windows.Input.InputManager.ProcessStagingArea()
at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.Run()
at System.Windows.Application.RunDispatcher(Object ignore)
at System.Windows.Application.RunInternal(Window window)
at System.Windows.Application.Run(Window window)
at System.Windows.Application.Run()
at EmailCheckerWPF.App.Main() in c:\Users\Luke\Documents\Caimbridge comp\EmailCheckerWPF\obj\Debug\App.g.cs:line 0
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:
In the bad old days of winforms, we had GDI+ types which were used for rendering UI.
Then came WPF. This was a complete rewrite of the UI stack for desktop applications. Along with creating different versions of UI elements (System.Windows.Forms.Window vs System.Windows.Controls.Window), the rendering stack and related classes were also rewritten. Wisely or not, many of the previous patterns were reproduced within this rewrite.
Winforms would remain in the framework for the unwise to stumble upon and cause themselves mischief. As we now have two (incompatible) versions of the same patterns coexisting within the framework, we also may unfortunately trap god-tier WPF developers.
One of the most common traps is importing the System.Drawing namespace. The equivalent for WPF developers is actually System.Windows.Media. Both namespaces contain many extremely similar yet incompatible types. If you aren't careful (and if you don't get good exception messages that tell you the effing namespace of the effing types you need versus the namespaces of the mothereffign types you are actually using), you'll using the wrong namespace and start slinging around GDI+ brushes.
Be careful, WPF developers. Make sure you're always using the WPF stack! Winforms are for the poor and uneducated. We don't want to associate with those kinds of folks, now, do we?