need to capture all keystrokes... api perhaps?

I want my usercontrol to close whenever the user presses the Escape key, whether the control has the focus or not. I'm just wondering how I can capture the keypress events with my usercontrol (just they keystrokes that happen in my form)

you need to set KeyPreview to True , then use the override process keypreview, here's a quick example...

VB Code:

[Color=Blue]Private[/color] [Color=Blue]Sub[/color] Form1_Load([Color=Blue]ByVal[/color] sender [Color=Blue]As[/color] System.Object, [Color=Blue]ByVal[/color] e [Color=Blue]As[/color] System.EventArgs) [Color=Blue]Handles[/color] [Color=Blue]MyBase[/color].Load
        KeyPreview = [Color=Blue]True
[/color]    [Color=Blue]End[/color] [Color=Blue]Sub
 
[/color]    [Color=Blue]Protected[/color] [Color=Blue]Overrides[/color] [Color=Blue]Function[/color] ProcessKeyPreview([Color=Blue]ByRef[/color] m [Color=Blue]As[/color] System.Windows.Forms.Message) [Color=Blue]As[/color] [Color=Blue]Boolean
[/color]        [Color=Blue]If[/color] m.WParam.ToInt32 = 27 [Color=Blue]Then
[/color]            [Color=Green]'///[/color] [Color=Green]do[/color] [Color=Green]stuff[/color] [Color=Green]to[/color] [Color=Green]your[/color] [Color=Green]UserControl[/color] [Color=Green]because[/color] [Color=Green]the[/color] [Color=Green]Escape[/color] [Color=Green]Key[/color] [Color=Green]was[/color] [Color=Green]pressed[/color] [Color=Green].[/color] [Color=Green]
[/color]        [Color=Blue]End[/color] [Color=Blue]If
[/color]    [Color=Blue]End[/color] [Color=Blue]Function[/color]

hmm weird, I thought I cant use keypreview since the user control doesnt have a keypreview property.... umm so the parent form's keypreview is set to true and then I can override the processKeyPreview sub in teh usercontrol? hmm

doesnt seem to work. I want the usercontrol to capture the keystrokes. :confused:

sorry i thought with this...

Quote:

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how I can capture the keypress events with my usercontrol (just they keystrokes that happen in my form)

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you wanted to catch the keystrokes in the Form that the usercontrol resided on.

Quote:

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Originally posted by dynamic_sysop
sorry i thought with this... you wanted to catch the keystrokes in the Form that the usercontrol resided on.

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well yeah I explained it a bit bad.. what I meant was that I dont want to capture all the keys that are pressed while the user is running windows (basically, I dont want a keylogger :) ) I want the usercontrol to capture any keys that are pressed in my application :D

I tried adding a KeyPress event for every control in my usercontrol. but for some reason the only event that works is the keyPress event for the usercontrol itself.

Use Application.AddMessageFilter function. You can have more than one MessageFilter to filter out different messages(mouse, keyboard, etc...). The following example is taken from MSDN.

Code:

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' Creates a message filter.
Public Class TestMessageFilter
  Implements IMessageFilter

  Public Function PreFilterMessage(ByRef m As System.Windows.Forms.Message) _
  As Boolean Implements IMessageFilter.PreFilterMessage
      ' Blocks all the messages relating to the left mouse button.
      If ((m.Msg >= 513) And (m.Msg <= 515)) Then
        Console.WriteLine("Processing the messages : " & m.Msg)
        Return True
      End If
      Return False
  End Function
End Class

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