MouseControl.cs

namespace AutoBlueStacks;

using System.Diagnostics;

public class MouseControl {
    private const int MOUSEEVENTF_LEFTDOWN = 0x2;
    private const int MOUSEEVENTF_LEFTUP = 0x4;
    private const int MOUSEEVENTF_MOVE = 0x0001;

    public void click(int x, int y) {
        NativeMethods.SetCursorPos(x, y);
        NativeMethods.mouse_event(MOUSEEVENTF_MOVE | MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);
    }
}

NativeMethods.cs

using System.Runtime.InteropServices;

namespace MyProgram;

public static class NativeMethods {
    // マウスカーソル移動
    [DllImport ("user32.dll")]
    public static extern bool SetCursorPos (int X, int Y);

    // ウィンドウを検索
    [DllImport("user32.dll", SetLastError=true, CharSet = CharSet.Auto)]
    public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

    // ウィンドウサイズを Rect に転写
    [DllImport("user32.dll")]
    public static extern bool GetWindowRect(IntPtr hwnd, ref Rect rectangle);

    // 指定ウィンドウのフォアグラウンド制御
    [DllImport("user32.dll")]
    public static extern bool SetForegroundWindow(IntPtr hWnd);

    // マウス操作の送出
    [DllImport("user32.dll")]
    public static extern void mouse_event(int dwFlags, int dx, int dy, int dwData, int dwExtraInfo);
}