为什么ReadProcessMemory返回的是０

一个老的单机游戏，自己想写个修改器，可是返回的是０
不知道是哪不对？帮我看看吧using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
            
namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        [DllImport("User32.dll")]
        public static extern int FindWindow(string s,string ss);        [DllImport("Kernel32.dll")]
        public static extern int OpenProcess(int dwDesiredAccess, bool bInheritHandle,int dwProcessId);        [DllImport("user32.dll",EntryPoint = "GetWindowThreadProcessId")]
        public static extern int GetWindowThreadProcessId(int hWnd,ref int lpdwProcessId);        [DllImport("kernel32.dll")]
        static extern bool ReadProcessMemory(uint hProcess,IntPtr lpBaseAddress, IntPtr lpBuffer, uint nSize, ref uint lpNumberOfBytesRead);        [DllImport("Kernel32.dll")]
        public static extern int CloseHandle(int handle);        public void game()
        {
            const int PROCESS_VM_READ = 16;
            int pid=0;
            GetWindowThreadProcessId(Phandle,ref pid);
            pro2=OpenProcess(PROCESS_VM_READ, false,pid);
            textBox2.Text = pro2.ToString();
            textBox4.Text = pid.ToString();
            timer2.Enabled = true;
        }        public Form1()
        {
            InitializeComponent();
        }        int Phandle,pro2;
        //uint pro2;
        private void button1_Click(object sender, EventArgs e)
        {
        }        private void Form1_Load(object sender, EventArgs e)
        {
        }        private void timer1_Tick(object sender, EventArgs e)
        {
            Phandle = FindWindow("Sword3 Class", null);
            if (Phandle != 0)
            {
                label1.Text = "游戏运行！";
                game();
                textBox1.Text = Phandle.ToString();
                timer1.Interval=10000;
            }
            else
            {
                label1.Text = "游戏未运行！";
                timer1.Interval=2000;
            }
        }        private void textBox1_TextChanged(object sender, EventArgs e)
        {        }        private void timer2_Tick(object sender, EventArgs e)
        {
            byte[] vBuffer = new byte[4];
            IntPtr vBytesAddress = Marshal.UnsafeAddrOfPinnedArrayElement(vBuffer, 0); // 得到缓冲区的地址
            uint vNumberOfBytesRead = 0;
            ReadProcessMemory((uint)pro2, (IntPtr)0xc0890c0, vBytesAddress, (uint)vBuffer.Length, ref vNumberOfBytesRead);
            int vInt = Marshal.ReadInt32(vBytesAddress);
            textBox5.Text = vInt.ToString();
        }        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            CloseHandle(pro2);
        }
    }
}