สอบถามปัญหาการใช้ FileUpload หน่อยครับ มันเป็นเฉพาะที่ใช้กับ ios เท่านั้นครับ ระบบ windows หรือ android ใช้ได้ปกติครับ

void Button1_Click(Object sender, EventArgs e)
    {    
        if (Button1.InnerText == "ลบออก")
        {
            Image1.Visible = false;
            Image1.ImageUrl = null;
            Button1.InnerText = "Upload1";
            try
            {
                Directory.Delete(Server.MapPath(strUser + "/image"), true);
            }
            catch { }
        }
        else
        {
            if (Button1.InnerText == "ลบไม่ได้")
            {

            }
            else
            {
                if (FileUpload1.HasFile)
                {
                    DirectoryInfo dir = new DirectoryInfo(Server.MapPath(strUser + "/image"));
                    if (!dir.Exists)
                    {
                        dir.Create();
                    }
                    FileUpload1.PostedFile.SaveAs(Server.MapPath(strUser + "/image/" + FileUpload1.FileName));
                    Image1.Visible = true;
                    Image1.ImageUrl = strUser + "/image/" + FileUpload1.FileName;
                    Button1.InnerText = "ลบออก";

                }
            }
        }
    }
    void Button2_Click(Object sender, EventArgs e)
    {
        if (Button2.InnerText == "ลบออก")
        {
            Image2.Visible = false;
            File.Delete(Server.MapPath(Image2.ImageUrl));
            Image2.ImageUrl = null;
            Button2.InnerText = "Upload2";
            Button1.InnerText = "ลบออก";
        }
        else
        {
            if (Button2.InnerText == "ลบไม่ได้")
            {

            }
            else
            {
                if (Button1.InnerText == "Upload1")
                {

                }
                else
                {
                    if (FileUpload1.HasFile)
                    {
                        FileUpload1.PostedFile.SaveAs(Server.MapPath(strUser + "/image/" + FileUpload1.FileName));
                        Image2.Visible = true;
                        Image2.ImageUrl = strUser + "/image/" + FileUpload1.FileName;
                        Button2.InnerText = "ลบออก";
                        Button1.InnerText = "ลบไม่ได้";
                    }
                }
            }
        }
    }
    void Button3_Click(Object sender, EventArgs e)
    {
        if (Button3.InnerText == "ลบออก")
        {
                Image3.Visible = false;
                File.Delete(Server.MapPath(Image3.ImageUrl));
                Image3.ImageUrl = null;
                Button3.InnerText = "Upload3";
                Button2.InnerText = "ลบออก";
        }
        else
        {
            if (Button3.InnerText == "ลบไม่ได้")
            {

            }
            else
            {
                if (Button2.InnerText == "Upload2")
                {

                }
                else
                {
                    if (FileUpload1.HasFile)
                    {
                        FileUpload1.PostedFile.SaveAs(Server.MapPath(strUser + "/image/" + FileUpload1.FileName));
                        Image3.Visible = true;
                        Image3.ImageUrl = strUser + "/image/" + FileUpload1.FileName;
                        Button3.InnerText = "ลบออก";
                        Button2.InnerText = "ลบไม่ได้";
                    }
                }
            }
        }
    }