ShellAndWaitSimple

ShellAndWaitSimple is a procedure that simply waits for the Shell'd program to terminate.  The function declaration is

Public Function F_7_AB_1_ShellAndWaitSimple( _
    A_7_AB_1_CommandLine As String) As Boolean

You provide in the parameter A_7_AB_1_CommandLine the command or name of the program that will be executed by the Shell function.  No validation is performed to ensure that A_7_AB_1_CommandLine is a valid string for Shell. A error will occur and a message box will be displayed if A_7_AB_1_CommandLine is not valid.

F_7_AB_1_ShellAndWaitSimple will wait until program is terminated.  It returns a result of TRUE if the Shell'd program was successfully started and terminated. It returns a result of FALSE if an error occurred. In case of an error, it displays a message box indicating the nature of the error. To use F_7_AB_1_ShellAndWaitSimple simply call the procedure and receive its return code. For example,

Dim Result As Boolean
Dim CommandLine As String
CommandLine = "Notepad.exe"
Result = F_7_AB_1_ShellAndWaitSimple(CommandLine)

The Result variable will receive the return value of  F_7_AB_1_ShellAndWaitSimple . If an error occurs, Shell may or may not have started the program, and the shell'd program may or may not still be running. These conditions depend on the nature of the error. In any case, if an error occurs, a message box is displayed indicating the nature of the error.

ShellAndWaitSimple will work in Office97 or later.  It will also work in Visual Basic version 6 with no changes. It has not been tested in the NET framework.

ShellAndWaitEnhanced

The ShellAndWaitEnhanced is a procedure that waits for the Shell'd program to terminate, in the same manner as ShellAndWaitSimple, but it will periodically display messages on a Userform's control . These messages can indicate to the user that the Shell'd program is still running and that the system has not become hung.   You can define whatever messages, and as many messages, as you desire. The messages in the A_7_AB_1_MessageArray array will be cycled at the interval specified by A_7_AB_1_MessageCycleTimeSeconds -- each message is displayed for this many seconds.  If you are calling the ShellAndWaitEnhanced procedure from within a form, that form may be displayed either modally or modelessly. If you call ShellAndWaitEnhanced from a standard code module, and use a form only to display the messages, that form must be displayed modelessly.

The function declaration for ShellAndWaitEnhanced is

A_7_AB_1_CommandLine
is the command line to be passed to the Shell function. This must be a valid command string. No validation is performed to ensure it is valid.  An error will occur and a message box will be displayed if the command string in invalid.

A_7_AB_1_MessageControl
is the control on a VBA Userform (typically a TextBox or Label control) in which status messages are to be displayed. Whatever control you use, that control must support either the Text or Caption property. An error will occur if the control does not support one of these properties. The messages to be displayed in A_7_AB_1_MessageControl are passed to the procedure in the A_7_AB_1_MessageArray array. The message control may be within another containing control such as a Frame control.

A_7_AB_1_MessageCycleTimeSeconds
is the number of seconds that each message in  A_7_AB_1_MessageArray will be displayed. The procedure cycles through the array, displaying each message for A_7_AB_1_MessageCycleTimeSeconds seconds. When the end of the array is reached, the procedure loops back to the beginning of the array.

A_7_AB_1_MessageArray
is an array of strings, each of which is a message to be displayed in the A_7_AB_1_MessageControl. Each message in  A_7_AB_1_MessageArray will be displayed for A_7_AB_1_MessageCycleTimeSeconds seconds. When the end of the array is reached, the procedure cycles back to the beginning of the array. There is no limit to the number of messages in the array.  An error will occur if  A_7_AB_1_MessageArray is not an array or it its data type is not a String.

A_7_AB_1_DoEventsMilliseconds
is the number of milliseconds that the procedure will wait before calling DoEvents to let other threads execute. A typical value is 500, every half second. If this parameter is less than or equal to zero, the default value of 500 is used.

ShellAndWaitEnhanced requires Office 2000 or later.  It has not been tested in the NET environment.

A_7_AB_1_ErrorNumber
is a reference to a Long type variable that will receive the error number if an error occured.

A_7_AB_1_ErrorText
is a reference to a String type variable that will receive the descriptive error text associated with  A_7_AB_1_ErrorNumber.

A_7_AB_1_MessageOnClose
is a message to display in the message control when the Shell'd program terminates. If this is omitted or is vbNullString, no closing message is  displayed in the control.

Downloads
VBA Versions
Download the source code workbook here, which includes both the modShellAndWaitSimple and modShellAndWaitEnhanced modules plus an example UserForm.

Download only the modShellAndWaitSimple.bas code module. You can Import this module to your existing VBAProject.

Download only the modShellAndWaitEnhanced.bas code module. You can Import this module to your existing VBAProject.

VB6 Versions
Download the entire VB6 Project here. This includes a test userform frmTest and the two module files. The test form allows you to select either ShellAndWaitSimple or ShellAndWaitEnhanced, and in the case of ShellAndWaitEnhanced, whether the message control is passed as a refrence to a form control or as an HWnd.

Download only the modShellAndWaitSimpleVB6.bas code module. This contains only the ShellAndWaitSimple function and  supporting functions and declarations.   

Download only the modShellAndWaitEnhancedVB6.bas code module. This contains only the ShellAndWaitEnhanced function and supporting functions and declaratiolns.

Full documentation is provided in all the download files.