www.pudn.com > SnapLibrary.rar > Snapshot.cs

using System; 
using System.Collections.Generic; 
using System.Text; 
using System.Runtime.InteropServices; 
using System.Runtime.InteropServices.ComTypes; 
using System.Drawing; 
using System.Windows.Forms; 
 
namespace SnapLibrary 
{ 
    /// 
 
    /// ActiveX 组件快照类 
    /// AcitveX 必须实现 IViewObject 接口 
    ///  
    /// 作者:随飞 
    /// http://chinasf.cnblogs.com 
    /// chinasf@hotmail.com 
    /// 
 
    public class Snapshot 
    { 
        /// 
 
        /// 取快照 
        /// 
 
        /// Com 对象 
        /// 图象大小 
        ///  
        public Bitmap TakeSnapshot(object pUnknown, Rectangle bmpRect) 
        { 
            if (pUnknown == null) 
                return null; 
            //必须为com对象 
            if (!Marshal.IsComObject(pUnknown)) 
                return null; 
            //IViewObject 接口 
            SnapLibrary.UnsafeNativeMethods.IViewObject ViewObject = null; 
            IntPtr pViewObject = IntPtr.Zero; 
            //内存图 
            Bitmap pPicture = new Bitmap(bmpRect.Width, bmpRect.Height); 
            Graphics hDrawDC = Graphics.FromImage(pPicture); 
            //获取接口 
            object hret = Marshal.QueryInterface(Marshal.GetIUnknownForObject(pUnknown), 
                ref UnsafeNativeMethods.IID_IViewObject, out pViewObject); 
            try 
            { 
                ViewObject = Marshal.GetTypedObjectForIUnknown(pViewObject, typeof(SnapLibrary.UnsafeNativeMethods.IViewObject)) as SnapLibrary.UnsafeNativeMethods.IViewObject; 
                //调用Draw方法 
                ViewObject.Draw((int)DVASPECT.DVASPECT_CONTENT, 
                    -1, 
                    IntPtr.Zero, 
                    null, 
                    IntPtr.Zero, 
                    hDrawDC.GetHdc(), 
                    new NativeMethods.COMRECT(bmpRect), 
                    null, 
                    IntPtr.Zero, 
                    0); 
            } 
            catch (Exception ex) 
            { 
                Console.WriteLine(ex.Message); 
                throw ex; 
            } 
            //释放 
            hDrawDC.Dispose(); 
            return pPicture; 
        } 
    } 
 
}