VS2022中WPF OpenFileDialog调试模式报错，无调试模式正常

问题详情 #

在WPF窗体中通过按钮触发OpenFileDialog，代码如下：

<Grid>
<Button Name="btn_rss_AddImage" Grid.Row="0" Grid.Column="1" Click="GetImageAttachment" Margin="20, 0">Choose Image</Button>
</Grid>

private void GetImageAttachment(object sender, RoutedEventArgs e)
{
    OpenFileDialog dlg = new();
    dlg.DefaultExt = ".xml";
    if (dlg.ShowDialog() == true)
    {
        string filename = dlg.FileName;
    }
}

调试模式运行时，输出窗口出现数百条重复异常，OpenFileDialog响应卡顿，异常从加载C:\Program Files\Norton\Suite\ashShell.dll后开始出现，示例异常：

(Win32): Loaded 'C:\Program Files\Norton\Suite\ashShell.dll'.
Exception thrown at 0x00007FFE2E9EB699 in WPF_ShipDataBase.exe: Microsoft C++ exception: asw::registry::exceptions::key_not_exists at memory location 0x0000008323D7A380.
Exception thrown at 0x00007FFE2E9EB699 in WPF_ShipDataBase.exe: Microsoft C++ exception: asw::storage::exit_callback_not_found_exception at memory location 0x0000008323D7C040.

但无调试模式启动时，OpenFileDialog可正常工作且无错误。

原因分析 #

这是Norton安全软件的shell扩展组件（ashShell.dll）与Visual Studio调试器的异常捕获机制冲突导致的：

• ashShell.dll作为系统shell扩展，会注入到所有打开文件对话框的进程中，包括你的WPF调试进程
• 该组件内部抛出的非致命C++异常，在调试模式下被Visual Studio的调试器捕获并输出，大量重复异常导致对话框响应卡顿
• 无调试模式下，系统默认忽略这类非致命异常，所以对话框正常工作

解决思路 #

1. 调整Visual Studio调试异常捕获设置 #

• 打开Visual Studio的调试 → Windows → 异常设置（快捷键：Ctrl+Alt+E）
• 在弹出窗口中，找到C++ Exceptions，取消勾选特定异常（asw::registry::exceptions::key_not_exists、asw::storage::exit_callback_not_found_exception）；或临时取消勾选整个C++ Exceptions的启用状态（注意调试其他代码时需恢复，避免遗漏重要异常）
• 开启仅我的代码（路径：Options → Debugging → General → Enable Just My Code），让调试器只监控你编写的代码抛出的异常，忽略第三方组件的异常

2. 临时禁用Norton的shell扩展 #

• 打开Norton安全软件设置，找到系统集成类选项，暂时关闭文件对话框相关的扩展功能
• 或使用命令卸载该shell扩展：regsvr32 /u "C:\Program Files\Norton\Suite\ashShell.dll"，调试完成后再用regsvr32 "C:\Program Files\Norton\Suite\ashShell.dll"恢复

3. 替代方案：调用Win32 API绕过WPF封装的对话框 #

如果上述方法无效，可以直接使用Win32原生的文件选择函数，避免加载第三方shell扩展：

[DllImport("comdlg32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern bool GetOpenFileName([In, Out] OPENFILENAME lpofn);

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
private struct OPENFILENAME
{
    public int lStructSize;
    public IntPtr hwndOwner;
    public IntPtr hInstance;
    public string lpstrFilter;
    public string lpstrCustomFilter;
    public int nMaxCustFilter;
    public int nFilterIndex;
    public string lpstrFile;
    public int nMaxFile;
    public string lpstrFileTitle;
    public int nMaxFileTitle;
    public string lpstrInitialDir;
    public string lpstrTitle;
    public int Flags;
    public ushort nFileOffset;
    public ushort nFileExtension;
    public string lpstrDefExt;
    public IntPtr lCustData;
    public IntPtr lpfnHook;
    public string lpTemplateName;
    public IntPtr pvReserved;
    public int dwReserved;
    public int FlagsEx;
}

private void GetImageAttachment(object sender, RoutedEventArgs e)
{
    OPENFILENAME ofn = new();
    ofn.lStructSize = Marshal.SizeOf(ofn);
    ofn.lpstrFilter = "XML Files (*.xml)\0*.xml\0All Files (*.*)\0*.*\0";
    ofn.lpstrFile = new string(new char[256]);
    ofn.nMaxFile = ofn.lpstrFile.Length;
    ofn.lpstrDefExt = "xml";
    ofn.Flags = 0x00080000 | 0x00001000; // OFN_NOCHANGEDIR | OFN_FILEMUSTEXIST

    if (GetOpenFileName(ref ofn))
    {
        string filename = ofn.lpstrFile;
    }
}

内容的提问来源于stack exchange，提问作者Fred F