Winform嵌入H5的exe软件显示异常如何解决？(语言-c#)

Winform嵌入H5的软件，能显示但是桌面多了半透明的框，这个咋整

以下是全部代码
using System;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading;

namespace EmbedDemo
{
public partial class frmMain : Form
{
private const int GWL_STYLE = (-16);
private const int WS_VISIBLE = 0x10000000;

    [DllImport("user32.dll", EntryPoint = "SetWindowLong", CharSet = CharSet.Auto)]
    public static extern IntPtr SetWindowLongPtr32(HandleRef hWnd, int nIndex, int dwNewLong);

    [DllImport("user32.dll", EntryPoint = "SetWindowLongPtr", CharSet = CharSet.Auto)]
    public static extern IntPtr SetWindowLongPtr64(HandleRef hWnd, int nIndex, int dwNewLong);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern long SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
    //SetParent(IntPtr hWndChild, IntPtr hWndNewParent);这个方法很重要，就是将hWndChild指向开启exe的窗体嵌入到hWndNewParent窗体的某个控件上，或者是窗体本身的容器
    [DllImport("user32.dll", SetLastError = true)]
    private static extern bool MoveWindow(IntPtr hwnd, int x, int y, int cx, int cy, bool repaint);
    // MoveWindow(IntPtr hwnd, int x, int y, int cx, int cy, bool repaint);这个方法是windows的api,见名知意，是移动hwnd所指的窗体到指定的位置，并且指定是否需要重绘

    [DllImport("user32.dll", SetLastError = true)]
    public static extern long SetWindowPos(IntPtr hwnd, long hWndInsertAfter, long x, long y, long cx, long cy, long wFlags);

    [DllImport("user32.dll", EntryPoint = "FindWindow")]
    public static extern IntPtr FindWindow(
              string lpClassName,
              string lpWindowName
             );

    [DllImport("kernel32.dll")]
    public static extern long GetLastError();

    public static IntPtr SetWindowLong(HandleRef hWnd, int nIndex, int dwNewLong)
    {

        if (IntPtr.Size == 4)
        {
            return SetWindowLongPtr32(hWnd, nIndex, dwNewLong);
        }
        return SetWindowLongPtr64(hWnd, nIndex, dwNewLong);
    }



    public frmMain()
    {
        InitializeComponent();
      
    }


    private void frmMain_Load(object sender, EventArgs e)
    {
        //以下这段代码是通过命令行方式调起一个exe程序，获取这个程序的句柄然后嵌入主的winform窗体中
        //string exePath = System.Configuration.ConfigurationManager.AppSettings["exePath"];
        
        ProcessStartInfo info = new ProcessStartInfo(@"D:\AAA\fxxxmm\Flexem.Box.Client.Desktop.exe");
        info.WindowStyle = ProcessWindowStyle.Minimized;
        info.UseShellExecute = false;
        info.CreateNoWindow = true;
        info.RedirectStandardOutput = false;

        Process appProcess = System.Diagnostics.Process.Start(info);
        appProcess.WaitForInputIdle();

        this.Show();

        try
        {
            EmbedProcess();

        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }


    /// 

    /// 将指定的程序嵌入指定的控件
    /// 
    private void EmbedProcess()
    {

        string title = System.Configuration.ConfigurationManager.AppSettings["Title"];//要查找的外部应用程序窗口标题

        IntPtr P = new IntPtr(0);

        while (true)
        {
            P = FindWindow(null, "FlexManager");//通过标题查找窗口句柄,当然也可以按class查找，如果需要查找子窗口需要FindWindowEx函数
            Thread.Sleep(100); 
            if (P == IntPtr.Zero)
                continue;
            else
                break;
        }
        try
        {
            // 将外部应用程序嵌入到本窗口 
            long ret = SetParent(P, this.Handle);
            if (ret == 0)
            {
                MessageBox.Show("ErrorCode:"+ GetLastError().ToString());
            }

            // 移除边框样式               
            SetWindowLong(new HandleRef(this, P), GWL_STYLE, WS_VISIBLE);

            //移动窗口
            MoveWindow(P, 0, 0, this.Width, this.Height, true);
        }
        catch (Exception ex1)
        {
            Console.WriteLine(ex1.Message);
        }
       
    }

}

}

如下图所示

查看了网上的方式，试了下，普通软件例如嵌入火绒安全软件，是能正常显示的，但又打开那个软件，就有那个半透明边框。可以拖动那个半透明边框，但是嵌入的软件随之变化。该怎么解决呢

就想嵌入的这个软件和嵌入其他软件一样正常显示就行，不要有那半透明边框什么的