Triggering events with Windows Presentation Form Controls

Question

Triggering events with Windows Presentation Form Controls

JohnCTX 636

I am having too many issues on how either to raise events or how to create delegates?

For example:

    private void rtb_TextChanged_6(object sender, TextChangedEventArgs e)
        {
            if (sender.Equals("Hello"))
            {
                MessageBox.Show("Will you count me in?");
            }
            //program does not display message box instead.

        }

Note that rtb is the name of a WPF Rich Text Box control.
It runs okay, but when I typed, Hello, message box does not appear.

What am I missing?

Answer accepted by question author

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Your answer

Answer 1

You could try to refer to the following code to extract text from RichTextBox and match the string.
The code of xaml:

<StackPanel>  
<RichTextBox  Name="rtbPaste" Height="50" TextChanged="rtbPaste_TextChanged" ></RichTextBox>  
</StackPanel>

The code of xaml.cs:

private void rtbPaste_TextChanged(object sender, TextChangedEventArgs e)  
    {  
     TextRange textRange = new TextRange(rtbPaste.Document.ContentStart, rtbPaste.Document.ContentEnd);  
      string _Text = textRange.Text.Replace(Environment.NewLine, "");  
      if (_Text.Equals("Hello"))  
      {  
        MessageBox.Show("Will you count me in?");  
      }  
}

The picture of result:

Answer 2

Sam of Simple Samples 5,571

Did you use the properties of the RichTextBox to add a handler? If there is not a handler there as shown in the following image then just double-click on the empty box for the handler and VS will create it for you.

JohnCTX 636 Reputation points

2021-08-18T01:44:49.067+00:00

Yes, I did use the properties tab.
I am going to download Microsoft Blend, and see if that mechanism works.
JohnCTX 636 Reputation points

2021-08-18T02:04:47.94+00:00

I have quickly migrated to Microsoft Blend.

Maybe this would give me better control over triggering events.
JohnCTX 636 Reputation points

2021-08-18T02:08:10.773+00:00

I have tried and run the code in the following events under the assigned WPF Rich Text Box control.
TextInput and TextChanged

Still no progress.

JohnCTX 636

 I may have a precursor to a solution.  And it would be by using the Key Down event.

 This source code snippet demonstrates if any key is pressed, then a message box appears.



    private void rtb_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
        {
            MessageBox.Show("Will you count me in?");
        }

JohnCTX 636 Reputation points

2021-08-18T02:32:37.117+00:00

To improve this code snippet, I would need to use a conditional block and to concatenate system keys.

Would that work the best?
JohnCTX 636 Reputation points

2021-08-18T02:40:04.847+00:00
I am still improving somewhat.

Here is the updated source code snippet. This snippet demonstrates a message box is invoked after user types the "I" key.

private void rtb_KeyDown(object sender, System.Windows.Input.KeyEventArgs e) { if (e.Key == Key.I) { MessageBox.Show("Will you count me in?"); } }

JohnCTX 636

I have found a solution. See if anyone can agree.

Here is another code snippet, except this one is under the Key Up event of the WPF Rich Text Box name.

       private void rtb_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.I)
                return;
                if (e.Key == Key.N)
                MessageBox.Show("Will you count me in?");

        }

JohnCTX 636 Reputation points

2021-08-18T03:41:29.587+00:00

So it is the Text Range constructor. Interesting.
Which of the two parameters and their types must pass on to?
Are they both have to be string types?

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Triggering events with Windows Presentation Form Controls

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