I doing for children handles of parent in C# code. I want to get progressbar value like 52% by another using SendMessage.

Left is progress value 56 and right is child handle 110C46 at middle label in progressbar

I tried this code:

static void Main(string[] args)
{
    Process app = Process.GetProcessesByName("ProgressBarTest").FirstOrDefault();
    if (app == null || app.MainWindowHandle == IntPtr.Zero) // Exit console app if no found
        return;
    var children = GetChildWindows(app.MainWindowHandle);   // Get all children of parent in another process
    var child = children[3];                                // I known that the child is a ProgressBar. 
    // Get ProgressBar all values using SendMessage
    var value1 = SendMessage(child.hWnd, PBM_GETPOS, IntPtr.Zero, IntPtr.Zero);
    var value2 = SendMessage(child.hWnd, PBM_GETSTATE, IntPtr.Zero, IntPtr.Zero);
    var value3 = SendMessage(child.hWnd, PBM_GETSTEP, IntPtr.Zero, IntPtr.Zero);
    Console.WriteLine("Value1 is " + value1.ToString());
    Console.WriteLine("Value2 is " + value2.ToString());
    Console.WriteLine("Value3 is " + value3.ToString());
    Console.ReadKey();
}

cmd result output:

I got 0 values using 100% correctly progressbar handle. I don’t known why i got return 0 always.

• I sure that the child handle is a progressbar handle.
• I checked using Spy++

Full source:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
namespace ProgressBarGetValue
{
    internal class Program
    {
        [DllImport("user32", CharSet = CharSet.Unicode)]
        public static extern IntPtr SendMessage(IntPtr hwnd, uint msg, IntPtr wParam, IntPtr lParam);
        public const int PBM_SETRANGE = 1001;
        public const int PBM_SETSTATE = 10;
        public const int PBM_SETPOS = 1004;
        public const int PBM_SETRANGE32 = 1006;
        public const int PBM_GETRANGE = 1008;
        public const int PBM_GETPOS = 1006;
        public const int PBM_SETBARCOLOR = 1009;
        public const int PBM_SETBKCOLOR = 0x2001;
        public const int PBM_SETMARQUEE = 1003;
        public const int PBM_GETSTATE = 1013;
        public const int PBM_GETSTEP = 1007;
        public const int PBM_STEPIT = 1005;
        public const int PBM_GETBKCOLOR = 0x2001;
        public const int PBM_GETBARCOLOR = 0x2009;
        static void Main(string[] args)
        {
            Process app = Process.GetProcessesByName("ProgressBarTest").FirstOrDefault();
            if (app == null || app.MainWindowHandle == IntPtr.Zero) // Exit console app if no found
                return;
            var children = Children.GetChildWindows(app.MainWindowHandle);   // Get all children of parent in another process
            var child = children[3];                                // I known that the child is a ProgressBar. 
            // Get ProgressBar all values using SendMessage
            var value1 = SendMessage(child.hWnd, PBM_GETPOS, IntPtr.Zero, IntPtr.Zero);
            var value2 = SendMessage(child.hWnd, PBM_GETSTATE, IntPtr.Zero, IntPtr.Zero);
            var value3 = SendMessage(child.hWnd, PBM_GETSTEP, IntPtr.Zero, IntPtr.Zero);
            Console.WriteLine("Value1 is " + value1.ToString());
            Console.WriteLine("Value2 is " + value2.ToString());
            Console.WriteLine("Value3 is " + value3.ToString());
            Console.ReadKey();
        }
    }
    public class Children
    {
        public class ChildInfo
        {
            public IntPtr hWnd { get; }
            public string ClassName { get; }
            public string Name { get; }
            public ChildInfo(IntPtr hwnd, string className, string name)
            {
                hWnd = hwnd;
                ClassName = className;
                Name = name;
            }
        }
        public delegate bool EnumWindowProc(IntPtr hwnd, IntPtr lParam);

        [DllImport("user32", CharSet = CharSet.Unicode)]
        public static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);
        [DllImport("user32", CharSet = CharSet.Unicode)]
        public static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
        [DllImport("user32.dll")]
        public static extern bool EnumChildWindows(IntPtr hwndParent, EnumWindowProc lpEnumFunc, IntPtr lParam);
        public static List<ChildInfo> GetChildWindows(IntPtr parentHandle)
        {
            var result = new List<ChildInfo>();

            EnumWindowProc childProc = (hwnd, lParam) =>
            {
                var classNameBuilder = new System.Text.StringBuilder(1024);
                GetClassName(hwnd, classNameBuilder, classNameBuilder.Capacity);

                var nameBuilder = new System.Text.StringBuilder(1024);
                GetWindowText(hwnd, nameBuilder, nameBuilder.Capacity);

                var childInfo = new ChildInfo(hwnd, classNameBuilder.ToString(), nameBuilder.ToString());
                result.Add(childInfo);

                return true;
            };

            EnumChildWindows(parentHandle, childProc, IntPtr.Zero);

            return result;
        }

    }
}