如何检查哪个程序是重点？

Question

I'm trying to have a timer check if a specific program is in focus every 250ms, but I just can't figure out how...

Current code:

using System.Diagnostics;
using System.Runtime.InteropServices;

namespace Hearthstone_Test
{
  public partial class Main : Form
  {
    private void timer1_Tick(object sender, EventArgs e)
    {
        var activatedHandle = GetForegroundWindow();
        if (GetForegroundWindow() == Process.GetProcessesByName("Hearthstone"));
        {
            Console.WriteLine("Not Focused");       // No window is currently activated
        }
        else 
        { 
            Console.WriteLine("Focused");
        }

        var procId = Process.GetCurrentProcess().Id;
        int activeProcId;
        GetWindowThreadProcessId(activatedHandle, out activeProcId);
    }
    [DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
    private static extern IntPtr GetForegroundWindow();
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern int GetWindowThreadProcessId(IntPtr handle, out int processId);
  }
}

Error is at line 11:

Operator '==' cannot be applied to operands of type 'Process[]' and 'IntPtr'

What I'm doing wrong?

Answer 1

This worked for me, slightly different as it returns the active window name:

public string getActiveWindowName()
{
    try
    {
        var activatedHandle = GetForegroundWindow();

        Process[] processes = Process.GetProcesses();
        foreach (Process clsProcess in processes)
        {

            if(activatedHandle == clsProcess.MainWindowHandle)
            {
                string processName = clsProcess.ProcessName;

                return processName;
            }
        }
    }
    catch { }
    return null;
}

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
private static extern IntPtr GetForegroundWindow();

the following will give you the actual window header text:

string processName = clsProcess.MainWindowTitle;

Answer 2

You're comparing an IntPtr returned by GetForegroundWindow() to an Process[] . As the name suggests, Process.GetProcessesByName can return multiple processes and as such you'll need to treat it as an array.

Save Process.GetProcessesByName("Hearthstone") into a variable, and iterate over each entry to see if it is the one that's focused. Also, you assume that the handle is the process ID; which probably isn't the case. The following code is untested.

...
var processes = Process.GetProcessesByName("Hearthstone");
foreach(Process p in processes) {
    if(activedHandle == p.Handle) {
        //A instance of the process Hearthstone is currently focused.
        ...
    } else {
        ...
    }
}