[2008] SendKeys problem

[Lerroy_Jenkins]

I have this code so far.

Private Sub btnUndo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUndo.Click
        SendKeys.Send("^Z")
    End Sub

I wanted the Undo button to be able to Undo the changes anywhere on the form (In any of the text boxes, quite a few!)

But this does not work. Any ideas?

[stanav]

That's becuase you're not sending the key to the right destination. When you click a button, the button is the control that has focus, and your sendkey sends the keys to it. What you need to do is looping thru all the controls on the form and call Undo method if the control is a textbox.

 Private Sub btnUndo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUndo.Click
        For Each ctrl As Control In Me.Controls
            If TypeOf ctrl Is TextBox Then
                DirectCast(ctrl, TextBox).Undo()
            End If
        Next
End Sub

[Lerroy_Jenkins]

Ahh right I see, well may I ask what happens if there is a richtextbox aswell?

Just create the For loop twice? Once for textbox and a second for richtextbox?

[stanav]

No, you can just add a ElseIf block to the existing code

If TypeOf ctrl Is TextBox Then
    DirectCast(ctrl, TextBox).Undo()
ElseIf TypeOf ctrl Is RichTextBox Then
    DirectCast(ctrl, RichTextBox).Undo()
End If

[Lerroy_Jenkins]

Hey, thanks for the help Stanav, I have taken into account what you have said, And I have tried this code. (I had to look up DirectCast as well, Oops).

But this still does not allow me to do what I want.

[stanav]

What is the expected result and what is the actual result when you run that code?

[Lerroy_Jenkins]

Sorry should have stated.

The expected result is if I type "Hello" into a text box and press the Undo button, then the "Hello" disapeares.

Just as .Undo does.

[stanav]

Sorry should have stated.

The expected result is if I type "Hello" into a text box and press the Undo button, then the "Hello" disapeares.

Just as .Undo does.

No, the undo method of a textbox or richtextbox will undo the last changes on the text. That is, if the textbox starts out blank, you then types "Hello" to it, when you call undo, the textbox will change back to blank. Now if you call undo again, it will call undo once more, it'll put "Hello" back. Now that you have "Hello" in the textbox, if you type in " World" and then call undo, it'll remove " World" and leave the textbox with only "Hello".
In your case, if you want the textbox to be blank, you need to either set its text to string.empty or just call the Clear method. Don't call undo.

[Lerroy_Jenkins]

If the person types Hello my name is Lerroy

and then they press Undo, just as Ctrl Z, I want Lerroy to disappear.

[stanav]

If the person types Hello my name is Lerroy

and then they press Undo, just as Ctrl Z, I want Lerroy to disappear.

That's not what Undo is... Undo, like the name suggests, will undo the last change. So if your textbox starts out blank and you type in "Hello my name is Lerroy", when you call undo, the textbox will be back to blank because it senses the whole sentence as the last change. If you want to remove just the last word from the text, you have to code it yourself using string.lastindexof to find the position of the last space then use string.substring to get the substring without the last word, you then set that substring to your textbox.text.

[Lerroy_Jenkins]

This works fine for a RTB

If RichTextBox1.CanUndo = True Then
            RichTextBox1.Undo()
        End If