How to Distinguish a DblClick from a Click Event (109865)


The information in this article applies to:

  • Microsoft Visual Basic Standard Edition for Windows 1.0
  • Microsoft Visual Basic Standard Edition for Windows 2.0
  • Microsoft Visual Basic Standard Edition for Windows 3.0
  • Microsoft Visual Basic Professional Edition for Windows 2.0
  • Microsoft Visual Basic Professional Edition for Windows 3.0
This article was previously published under Q109865

SUMMARY

Usually when you issue two consecutive mouse clicks on a form or object, you will receive a click event for the first mouse click and another click event or a double-click event for the second mouse click -- depending on the period of time between the mouse clicks.

At times, you may want to receive only the double-click event without the preceding click event. This article describes how to write code to accomplish this.

MORE INFORMATION

The following example demonstrates how to receive only a DblClick event on a form rather than a Click and then a DblClick event.

Step-by-Step Example

  1. Start a new project in Visual Basic. Form1 is created by default.
  2. Add a Timer control (Timer1) to Form1.
  3. Add the following code to the (general) (declarations) section of Form1: 
       ' The following Function gets the DoubleClickSpeed from the WIN.INI
   ' file. Windows uses this setting to determine how close together two
   ' consecutive mouse clicks must occur for it to be interpreted as
   ' a double-click.
   ' Enter the following Declare statement on one, single line:
   Declare Function GetProfileInt% Lib "Kernel" (ByVal lpAppName$,
      ByVal lpKeyName$, ByVal nDefault%)
  4. Add the following code to the specified event procedures: 
       Sub Form_Load ()
      clickSpeed% = GetProfileInt("Windows", "DoubleClickSpeed", 0)
      Timer1.Enabled = False         ' Timer should be off to begin with.
      Timer1.Interval = clickSpeed%  ' After the timer is turned on
                                     ' it will trigger the Timer Event
                                     ' after a specific amount of time
                                     ' equal to that of DoubleClickSpeed.
   End Sub

   Sub Form_Click ()
      Timer1.Enabled = True          ' Turn the timer on. If another mouse
                                     ' click does not occur within the
                                     ' DoubleClickSpeed interval, the
                                     ' Timer1_Timer Event will fire.
   End Sub

   Sub Form_DblClick ()
      Timer1.Enabled = False         ' Turn off the timer. This
                                     ' prevents the Timer1_Timer event
                                     ' from firing and thus the code
                                     ' for a single click will not be
                                     ' processed.
      Print "This is a double-click" ' Code for double-click goes here.
   End Sub

   Sub Timer1_Timer ()
      ' If this event occurs then there has not been another mouse
      ' click since the previous one within the DoubleClickSpeed
      ' time interval. Thus there will be two Click events rather
      ' than a DblClick Event.
      Timer1.Enabled = False         ' Turn off the timer so the
                                     ' Timer1_Timer Event does not
                                     ' continue to fire.
      Print "This is a Single Click" ' Code for single click goes here.
   End Sub
  5. Run the program.
  6. Click once, wait a while, click again to receive two single clicks.
  7. Click twice quickly to receive a double-click with no preceding single click.
NOTE: The single click code will not occur until the DoubleClickSpeed interval passes and the Timer1_Timer event is fired.
Modification Type:MajorLast Reviewed:12/9/2003
Keywords:KB109865
©2003 Microsoft Corporation. All rights reserved.