线程,位图方法c#

我试图在c#中获得浏览器控件的屏幕截图。当我试图初始化浏览器控件时，我得到一个错误:

ActiveX控件'8856f961-340a-11d0-a96b-00c04fd705a2'不能实例化，因为当前线程不在单线程中公寓。

现在我正在尝试的是，我正在创建一个线程，我在那里做所有的初始化，但是当我试图声明Response.ContentType = "image/jpeg";时，我得到了一个错误错误信息是:

响应在此上下文中不可用。

下面是我的完整代码:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Net;
using System.Text.RegularExpressions;
using System.Drawing;
using System.Threading;
using System.Drawing.Imaging;
using System.Text;
using System.Windows.Forms;
public partial class _Default : System.Web.UI.Page
{
    string currentPageUrl = "";
    Bitmap bmp = new Bitmap(1024, 768);
    protected void Page_Load(object sender, EventArgs e)
    {       
    }
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        if (Request.ServerVariables["HTTPS"].ToString() == "")
        {
            currentPageUrl = Request.ServerVariables["SERVER_PROTOCOL"].ToString().ToLower().Substring(0, 4).ToString() + "://" + Request.ServerVariables["SERVER_NAME"].ToString() + ":" + Request.ServerVariables["SERVER_PORT"].ToString() + Request.ServerVariables["SCRIPT_NAME"].ToString();
        }
        else
        {
            currentPageUrl = Request.ServerVariables["SERVER_PROTOCOL"].ToString().ToLower().Substring(0, 5).ToString() + "://" + Request.ServerVariables["SERVER_NAME"].ToString() + ":" + Request.ServerVariables["SERVER_PORT"].ToString() + Request.ServerVariables["SCRIPT_NAME"].ToString();
        }
        Thread thr = new Thread(new ThreadStart(OptimizeWebBrowserAndCreateImage));
        thr.SetApartmentState(ApartmentState.STA);
        thr.Start();   
    }   
    protected void OptimizeWebBrowserAndCreateImage()
    {
        System.Windows.Forms.WebBrowser browser = new System.Windows.Forms.WebBrowser();
        browser.ScrollBarsEnabled = false;
        browser.ScriptErrorsSuppressed = true;
        browser.Navigate(currentPageUrl);
        while (browser.ReadyState != WebBrowserReadyState.Complete)
            System.Windows.Forms.Application.DoEvents();
        System.Threading.Thread.Sleep(1500);
        int width = browser.Document.Body.ScrollRectangle.Width;
        int height = browser.Document.Body.ScrollRectangle.Height;
        browser.Width = width;
        browser.Height = height;
        System.Drawing.Bitmap bmp = new Bitmap(width, height);
        browser.DrawToBitmap(bmp, new System.Drawing.Rectangle(0, 0, width, height));      
        Response.ContentType = "image/jpeg";
        Response.AppendHeader("Content-Disposition", "attachment; filename=screenshot.jpg");
        bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
        bmp.Dispose();
        bmp.Dispose();
        Response.End();
    }
}

我在Response.ContentType = "image/jpeg";

上遇到了一个错误我很感谢你的帮助，我希望有人能帮我解决这个问题。提前感谢，Laziale

Updated Version based on Henk's advice:using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Net;
using System.Text.RegularExpressions;
using System.Drawing;
using System.Threading;
using System.Drawing.Imaging;
using System.Text;
using System.Windows.Forms;
public partial class _Default : System.Web.UI.Page
{
    string currentPageUrl = "";
    Bitmap bmp = new Bitmap(1024, 768);
    Thread thr = null;
    protected void Page_Load(object sender, EventArgs e)
    {       
    }
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        if (Request.ServerVariables["HTTPS"].ToString() == "")
        {
            currentPageUrl = Request.ServerVariables["SERVER_PROTOCOL"].ToString().ToLower().Substring(0, 4).ToString() + "://" + Request.ServerVariables["SERVER_NAME"].ToString() + ":" + Request.ServerVariables["SERVER_PORT"].ToString() + Request.ServerVariables["SCRIPT_NAME"].ToString();
        }
        else
        {
            currentPageUrl = Request.ServerVariables["SERVER_PROTOCOL"].ToString().ToLower().Substring(0, 5).ToString() + "://" + Request.ServerVariables["SERVER_NAME"].ToString() + ":" + Request.ServerVariables["SERVER_PORT"].ToString() + Request.ServerVariables["SCRIPT_NAME"].ToString();
        }
        thr = new Thread(new ThreadStart(OptimizeWebBrowserAndCreateImage));
        thr.SetApartmentState(ApartmentState.STA);
        thr.Start();      
    }  
    protected void OptimizeWebBrowserAndCreateImage()
    {
        /*
        Bitmap bitmap = new Bitmap(CaptureWebPage2(currentPageUrl));
        Response.ContentType = "image/jpeg";
        Response.AppendHeader("Content-Disposition", "attachment; filename=screenshot.jpg");
        bitmap.Save(Response.OutputStream, ImageFormat.Jpeg);
        bitmap.Dispose();
        bitmap.Dispose();
        Response.End();
        */
        System.Windows.Forms.WebBrowser browser = new System.Windows.Forms.WebBrowser();
        browser.ScrollBarsEnabled = false;
        browser.ScriptErrorsSuppressed = true;
        browser.Navigate(currentPageUrl);
        while (browser.ReadyState != WebBrowserReadyState.Complete)
            System.Windows.Forms.Application.DoEvents();
        System.Threading.Thread.Sleep(1500);
        int width = browser.Document.Body.ScrollRectangle.Width;
        int height = browser.Document.Body.ScrollRectangle.Height;
        browser.Width = width;
        browser.Height = height;
        System.Drawing.Bitmap bmp = new Bitmap(width, height);
        browser.DrawToBitmap(bmp, new System.Drawing.Rectangle(0, 0, width, height));      
     /*  Response.ContentType = "image/jpeg";
        Response.AppendHeader("Content-Disposition", "attachment; filename=screenshot.jpg");
        bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
        bmp.Dispose();
        bmp.Dispose();
        Response.End();
      */
    }
    protected void Page_PreRender(object sender, EventArgs e)
    {
        if (thr != null)
        {
            thr.Join();
            Response.ContentType = "image/jpeg";
            Response.AppendHeader("Content-Disposition", "attachment; filename=screenshot.jpg");
            bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
            bmp.Dispose();
            //bmp.Dispose();
            Response.End();
        }
    }
}