如何将stdole.stdPicture转换为C#中的.net映像？
如何将stdole.stdPicture转换为C#中的.net映像？
提问于 2022-03-08 15:09:29
我正在为Outlook构建一个外接程序，其中我将所有exchange用户从全局地址列表复制到本地联系人。
问题是我也想传输exchange用户的图片，但是exchUser.GetPicture()返回一个stdole.stdPicture，我还没有找到一个下载或转换成一个映像/jpg/.
在这里，从全局地址列表中获取exchange用户的代码：
private void EnumerateGAL()
{
Outlook.AddressList gal = Application.Session.GetGlobalAddressList();
if (gal != null)
{
for (int i = 1; i <= gal.AddressEntries.Count - 1; i++)
{
Outlook.AddressEntry addrEntry = gal.AddressEntries[i];
Outlook.ExchangeUser exchUser = addrEntry.GetExchangeUser();
if (addrEntry.AddressEntryUserType == Outlook.OlAddressEntryUserType.olExchangeUserAddressEntry
&& exchUser.CompanyName == "")
{
CreateContact(exchUser);
//exchUser.GetPicture() returns stdole.stdPicture
}
}
}
return;
}我找到的最接近的解决方案是stdole.IPictureDisp的转换，它返回位图，但IPuctureDisp和stdPicture与我在某个地方看到的不一样。
public static System.Drawing.Image ConvertPicture(stdole.IPictureDisp image)
{
int type = image.Type;
if (type == 1)
{
IntPtr hPal = (IntPtr)image.hPal;
return Image.FromHbitmap((IntPtr)image.Handle, hPal);
}
return null;
}最后，我需要下载图片，因为我只能上传一张图片给有路径的联系人。那么，有什么方法可以下载stdPicture或将其转换为能够下载吗？
Stack Overflow用户
回答已采纳
发布于 2022-03-08 15:48:26
完成这项工作的方法主要有四种。
“传统”方法是在GetIPictureDispFromPicture类中使用System.Windows.Forms.AxHost和GetPictureFromIPicture方法。它们都是类的受保护成员，因此不能在外部使用它们。因此，通常会对AxHost类进行子类并公开内部调用基类受保护方法的公共方法。这种方法允许您在两个方向进行转换：
internal class AxHostConverter : AxHost
{
private AxHostConverter() : base("") { }
static public stdole.IPictureDisp ImageToPictureDisp(Image image)
{
return (stdole.IPictureDisp)GetIPictureDispFromPicture(image);
}
static public Image PictureDispToImage(stdole.IPictureDisp pictureDisp)
{
return GetPictureFromIPicture(pictureDisp);
}
}第二个选择是使用OleLoadPicture或OleCreatePictureIndirect。这里有一篇关于这个主题的支持文章。OleLoadPicture创建一个新的图片对象，并从流的内容中初始化它。
internal class OleCreateConverter
{
[DllImport("oleaut32.dll", EntryPoint = "OleCreatePictureIndirect",
CharSet = CharSet.Ansi, ExactSpelling = true, PreserveSig = true)]
private static extern int OleCreatePictureIndirect(
[In] PictDescBitmap pictdesc, ref Guid iid, bool fOwn,
[MarshalAs(UnmanagedType.Interface)] out object ppVoid);
const short _PictureTypeBitmap = 1;
[StructLayout(LayoutKind.Sequential)]
internal class PictDescBitmap
{
internal int cbSizeOfStruct = Marshal.SizeOf(typeof(PictDescBitmap));
internal int pictureType = _PictureTypeBitmap;
internal IntPtr hBitmap = IntPtr.Zero;
internal IntPtr hPalette = IntPtr.Zero;
internal int unused = 0;
internal PictDescBitmap(Bitmap bitmap)
{
this.hBitmap = bitmap.GetHbitmap();
}
}
public static stdole.IPictureDisp ImageToPictureDisp(Image image)
{
if (image == null || !(image is Bitmap))
{
return null;
}
PictDescBitmap pictDescBitmap = new PictDescBitmap((Bitmap)image);
object ppVoid = null;
Guid iPictureDispGuid = typeof(stdole.IPictureDisp).GUID;
OleCreatePictureIndirect(pictDescBitmap, ref iPictureDispGuid, true, out ppVoid);
stdole.IPictureDisp picture = (stdole.IPictureDisp)ppVoid;
return picture;
}
public static Image PictureDispToImage(stdole.IPictureDisp pictureDisp)
{
Image image = null;
if (pictureDisp != null && pictureDisp.Type == _PictureTypeBitmap)
{
IntPtr paletteHandle = new IntPtr(pictureDisp.hPal);
IntPtr bitmapHandle = new IntPtr(pictureDisp.Handle);
image = Image.FromHbitmap(bitmapHandle, paletteHandle);
}
return image;
}
}您的第三个选择是使用VB6兼容性库，这里有文档。要使用它，您需要添加对Microsoft.VisualBasic.Compatibility.dll的引用，该引用列在Add References对话框的.NET选项卡上(它驻留在Add References对话框中)。然后，您可以在ImageToIPictureDisp类中使用Support和IPictureDispToImage方法。这显然是迄今为止最简单的方法，尽管它确实引入了VB6兼容性DLL。在内部，VB6兼容性代码看起来很像上面的第二个选项--使用OleCreatePictureIndirect。
using Microsoft.VisualBasic.Compatibility.VB6;
internal class VB6CompatibilityConverter
{
public static stdole.IPictureDisp ImageToPictureDisp(Image image)
{
return (stdole.IPictureDisp)Support.ImageToIPictureDisp(image);
}
public static Image PictureDispToImage(stdole.IPictureDisp pictureDisp)
{
return Support.IPictureDispToImage(pictureDisp);
}
}最后，您可以自己实现IPictureDisp和IPicture。如果您只想从图像转换到IPictureDisp，但这并不能帮助您向相反的方向转换，这是很好的。下面的实现依赖于图像实际上是派生的位图类型，因为我们在内部调用Bitmap.GetHbitmap。如果您想保持对泛型Image类型的支持，那么您将不得不做更多的工作来对一堆无文档的GDI方法进行p/调用
internal class PictureDispConverter
{
public static stdole.IPictureDisp BitmapToPictureDisp(Bitmap bitmap)
{
return new PictureDispImpl(bitmap);
}
public static Image PictureDispToBitmap(stdole.IPictureDisp pictureDisp)
{
// TODO
return null;
}
}
internal class PictureDispImpl : stdole.IPictureDisp, stdole.IPicture
{
#region Init
[DllImport("gdi32.dll")]
static extern void DeleteObject(IntPtr handle);
private Bitmap _image;
private IntPtr _handle;
public PictureDispImpl(Bitmap image)
{
_image = image;
}
~PictureDispImpl()
{
if (_handle != IntPtr.Zero)
{
DeleteObject(_handle);
}
}
#endregion
#region IPictureDisp Members
public int Width
{
get { return _image.Width; }
}
public int Height
{
get { return _image.Height; }
}
public short Type
{
get { return 1; }
}
public int Handle
{
get
{
if (_handle == IntPtr.Zero)
{
_handle = _image.GetHbitmap();
}
return _handle.ToInt32();
}
}
public int hPal
{
get { return 0; }
set { }
}
public void Render(
int hdc, int x, int y, int cx, int cy, int xSrc, int ySrc, int cxSrc, int cySrc, IntPtr prcWBounds)
{
Graphics graphics = Graphics.FromHdc(new IntPtr(hdc));
graphics.DrawImage(
_image, new Rectangle(x, y, cx, cy), xSrc, ySrc, cxSrc, cySrc, GraphicsUnit.Pixel);
}
#endregion
#region IPicture Members
public int Attributes
{
get { return 0; }
}
public int CurDC
{
get { return 0; }
}
public bool KeepOriginalFormat
{
get { return false; }
set { }
}
public void PictureChanged()
{
}
public void SaveAsFile(IntPtr pstm, bool fSaveMemCopy, out int pcbSize)
{
pcbSize = 0;
}
public void SelectPicture(int hdcIn, out int phdcOut, out int phbmpOut)
{
phdcOut = 0;
phbmpOut = 0;
}
public void SetHdc(int hdc)
{
}
#endregion
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/71397239
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