Vbscript execute a function rarely, with chances u

问题:

New to Vbscript. I made a random function with two parameters.And called it It resulted in a infinite loop opening infinite program.

Function random(v1,v2)
 Randomize
 rdm =(Int((v2 - v1 + 1)* Rnd + v1))
End Function 

Function download()
 Set shell = createobject("wscript.shell"):shell.run "mspaint.exe"   
End function

'I want this download function to run rarely
Do
  Call random(100,1000)
  If  rdm>700 And rdm <760 Then 
  Call download()
  End If
loop

回答1:

Added code to return value and Added Exit Do statement to break the loop.

Hope this will help you..

Function random(v1,v2)
 Randomize
 random=(Int((v2 - v1 + 1)* Rnd + v1))
End Function 

Function download()
 Set shell = createobject("wscript.shell"):shell.run "mspaint.exe"   
 download=true
End function

'I want this download function to run rarely
Do
  rdm= random(100,1000)
  If  rdm>700 And rdm <760 Then 
  Call download()
  Exit Do  ' this will break the loop if condition is met 
  End If
loop

回答2:

If your intention is to write a script which, when called, invokes a function with probability 60/900 = 1/15, you are making things too complicated. There is no reason to generate a random integer in the range 100 to 1000 just to check if it lies in a certain range. If you want to trigger an action with probability p, have a line which looks like:

If rnd() < p Then 'action

If I understand your intentions, your entire script could be written as:

Randomize

Set shell = createobject("wscript.shell")   

If rnd() < 1/15 Then shell.Run "mspaint.exe"

Most of the time you run the above script nothing happens, but an average of 1/15 times it will open paint.