Getting output from running command line app in Inno Setup

Question

The scenario is that we wrote a console application, that we want to call during an Inno Setup and read its output. In contrast to this problem it is necessary to read this output from Inno Setup while the other program is still running. The output shall contain progress information of the runnig application (double or int values), that we want to display in Inno with the ProgressGauge. The app is a simple executable written in C# and can run from some seconds to several minutes.

Is this possible and if yes, can it be done without freezing the GUI of Inno Setup (as the application can take some time)?

Answer 1

With TLama pointing to the progress bar messages I was able to solve the problem.

At first I needed to pass the progress bar handle from Inno to my C# app. For this I created a function that would return me the int-pointer as a string

function GetProgressHandle(Param: String): String;
begin
  Result := Format('%d',[WizardForm.ProgressGauge.Handle]);
end;

and use it in the Run-section when calling my app:

[Run]
Filename: "{app}\myApp.exe"; Parameters: "{code:GetProgressHandle}"; ....

In C# I read the int-pointer from the console arguments and use it to create an IntPtr :

IntPtr pointer = new IntPtr(Int32.Parse(args[0]));

To send the messages to the progress bar I imported user32.dll and re-defined the needed constants, that normally can be found in commctrl.h:

[DllImport("user32.dll")]
public static extern IntPtr PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

public const uint PBM_SETRANGE = 0x401;
public const uint PBM_SETPOS = 0x402;

Finally, I could set the range of the progress bar from 0 to max and a specific position pos with

PostMessage(pointer, PBM_SETRANGE, (IntPtr)0, (IntPtr)(max << 16));    
PostMessage(pointer, PBM_SETPOS, (IntPtr)pos, (IntPtr)0);

NOTE : Changing the progress bar position didn't seem to update the Inno Setup Window immediately. I tested it by increasing the position every 500 ms but there where noticeable differences (pauses were more in the range of ca. 0.2-0.8 ms). For my case it is not important that changing the progress bar is accurately timed, but I assume that the Inno Setup window can be updated in a similar way (with the specific handle and a different message-constant) for those who need this.