你在正確的軌道上。有兩種方法可以顯示打開的文件對話框。較新的方法使用IFileOpenDialog（其延伸IFileDialog）。使用這種方法，過濾器描述和文件規範是使用COMDLG_FILTERSPEC結構定義的。這使得分開的領域更加自然。
如果您想使用此方法從組合框中刪除文件規格，那麼您必須添加自己的自定義控件或在對話框上操作組合框控件。雖然這會變得混亂，但應該是可行的。
舊派方法使用GetOpenFileName和OPENFILENAME結構。這一招的訣竅是，它可以顯示一箇舊的外觀或新的外觀對話框。外觀由OPENFILENAME結構中的設置決定，如here所述。
WinForms OpenFileDialog的問題在於，它們在AutoUpgradeEnabled爲true時使用IFileOpenDialog，在AutoUpgradeEnabled爲false時使用舊外觀時使用GetOpenFileName。
WPF版本不給你一個選擇，但仍然使用與WinForms相同的邏輯，但根據需要自動執行。這對於.NET 4中的WPF來說是正確的，在以前的版本中，它只會以舊的外觀使用GetOpenFileName。
繪畫最有可能使用GetOpenFileName以新外觀。這裏是一個C＃示例：
private delegate IntPtr WndProc(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
private const int OFN_ALLOWMULTISELECT = 0x00000200;
private const int OFN_CREATEPROMPT = 0x00002000;
private const int OFN_DONTADDTORECENT = 0x02000000;
private const int OFN_ENABLEHOOK = 0x00000020;
private const int OFN_ENABLEINCLUDENOTIFY = 0x00400000;
private const int OFN_ENABLESIZING = 0x00800000;
private const int OFN_ENABLETEMPLATE = 0x00000040;
private const int OFN_ENABLETEMPLATEHANDLE = 0x00000080;
private const int OFN_EXPLORER = 0x00080000;
private const int OFN_EXTENSIONDIFFERENT = 0x00000400;
private const int OFN_FILEMUSTEXIST = 0x00001000;
private const int OFN_FORCESHOWHIDDEN = 0x10000000;
private const int OFN_HIDEREADONLY = 0x00000004;
private const int OFN_LONGNAMES = 0x00200000;
private const int OFN_NOCHANGEDIR = 0x00000008;
private const int OFN_NODEREFERENCELINKS = 0x00100000;
private const int OFN_NOLONGNAMES = 0x00040000;
private const int OFN_NONETWORKBUTTON = 0x00020000;
private const int OFN_NOREADONLYRETURN = 0x00008000;
private const int OFN_NOTESTFILECREATE = 0x00010000;
private const int OFN_NOVALIDATE = 0x00000100;
private const int OFN_OVERWRITEPROMPT = 0x00000002;
private const int OFN_PATHMUSTEXIST = 0x00000800;
private const int OFN_READONLY = 0x00000001;
private const int OFN_SHAREAWARE = 0x00004000;
private const int OFN_SHOWHELP = 0x00000010;
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public class OPENFILENAME_I {
public int lStructSize;
public IntPtr hwndOwner;
public IntPtr hInstance;
public string lpstrFilter;
public IntPtr lpstrCustomFilter;
public int nMaxCustFilter;
public int nFilterIndex;
public IntPtr lpstrFile;
public int nMaxFile = 260;
public IntPtr lpstrFileTitle;
public int nMaxFileTitle = 260;
public string lpstrInitialDir;
public string lpstrTitle;
public int Flags;
public short nFileOffset;
public short nFileExtension;
public string lpstrDefExt;
public IntPtr lCustData;
public WndProc lpfnHook;
public string lpTemplateName;
public IntPtr pvReserved;
public int dwReserved;
public int FlagsEx;
}
[DllImport("comdlg32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
private static extern bool GetOpenFileName([In, Out] OPENFILENAME_I ofn);
private void ShowOpenFileDialog() {
OPENFILENAME_I ofn = new OPENFILENAME_I();
ofn.lStructSize = Marshal.SizeOf(typeof(OPENFILENAME_I));
ofn.lpstrFilter = "Text Files (*.txt)\0*.txt\0All Files\0*.*\0\0";
ofn.nFilterIndex = 0;
//ofn.Flags = OFN_EXPLORER | OFN_ENABLEHOOK | OFN_ENABLESIZING | OFN_NODEREFERENCELINKS | OFN_HIDEREADONLY | OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
ofn.Flags = OFN_ENABLESIZING | OFN_NODEREFERENCELINKS | OFN_HIDEREADONLY | OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
GetOpenFileName(ofn);
}
您可以嘗試重新加入OFN_EXPLORER和/或OFN_ENABLEHOOK標誌，也將恢復到老樣子。但按原樣，上面的代碼將顯示一個打開的文件對話框，所有文件都不顯示它的文件規範。
我從來沒有見過在過濾元件會自動添加行爲。什麼是您使用的OpenFileDialog的完整名稱空間？ – 2011-04-20 15:39:47
lol只是在Windows 7的VS 2010中試過這個，現在我得到了相同的結果... – 2011-04-20 15:46:13
我正在使用Microsoft.Win32.OpenFileFilter。沒有自動添加過濾元素。相反，括號中的內容會自動添加。 – 2011-04-20 15:46:18