Process.Start 没有扩展名的文件
Process.Start a file without Extension
我们已经知道 System.Diagnostics.Process.Start("C:\filename.png") 是如何工作的，但是如果文件名不以扩展名结尾怎么办？
如何使用与 .png 扩展名关联的默认程序 运行 没有扩展名的文件名？
类似于：
openFile("C:\filename","PNG")
您当然可以将文件名和扩展名拼凑在一起，希望最好。
或者测试文件扩展名是否具有预定义的 Opener，注册表中的一个条目将扩展名与可以处理该文件格式的应用程序相关联。
系统提供了一个 API - AssocQueryString - 来提供此信息（当然，您也可以手动查找注册表，但情况可能会发生变化，并且 API 功能已经知道了）。
它也可以用于其他一些任务。
查看声明部分以找到 VB.Net 函数调用和相关的枚举数。
此辅助方法仅允许调用 API 函数而无需指定特殊标志。您只需定义要检索的信息类型。
例如：
AssociationQuery.Executable:
returns 与指定扩展关联的可执行文件的完整路径。
AssociationQuery.Command:
returns Rundll32 命令，当文件扩展名不直接与独立可执行文件关联，而是与 dll 或系统小程序关联时，Shell 执行该命令。
或者 return 与 Shell 动词关联的命令（打开、打印、编辑、新建等）。
AssociationQuery.FriendlyDocName:
returns 关联文件类型的友好名称。例如，.docx 扩展名将 return Microsoft Word 文档（取决于本地语言）。
AssociationQuery.FriendlyAppName:
returns 关联应用程序的友好名称。例如，.docx 扩展名将 return Word 2016（取决于本地语言）。
有关这些开关的更多信息以及声明部分中其他可用开关的说明，请参见下面的示例。
helper 方法（如下所述调用此方法）：
Public Function FileExtentionInfo(AssociationType As AssociationQuery, Extension As String) As String
If (Extension.Length <= 1) OrElse Not Extension.StartsWith(".") Then
Return String.Empty
Else
Dim flags As AssocFlags = AssocFlags.NoTruncate Or AssocFlags.RemapRunDll
Return ShellExtensionInfo(True, AssociationType, flags, Extension)
End If
End Function
worker方法：
Private Function ShellExtensionInfo(Verify As Boolean, AssociationType As AssociationQuery, flags As AssocFlags, Extension As String) As String
Dim pcchOut As UInteger = 0
flags = flags Or (If(Verify, AssocFlags.Verify, AssocFlags.IgnoreUnknown))
AssocQueryString(flags, AssociationType, Extension, Nothing, Nothing, pcchOut)
If pcchOut = 0 Then
Return String.Empty
Else
Dim pszOut As New StringBuilder(CType(pcchOut, Integer))
AssocQueryString(flags, AssociationType, Extension, Nothing, pszOut, pcchOut)
Return pszOut.ToString()
End If
End Function
要得到结果，只需调用辅助函数，询问你想要什么样的信息或关联(AssociationQuery)。
例如，这个调用：
Dim Executable As String = FileExtentionInfo(AssociationQuery.Executable, ".docx")
可以return（取决于安装的软件和用户的选择）：
C:\Program Files\Microsoft Office\Office16\WINWORD.EXE
如前所述，并非所有扩展都有关联的可执行文件。某些文件扩展名可能映射到由 Rundll32.exe 启动的系统 applet/tool。
在这种情况下，使用 AssociationQuery.Executable 作为参数可能 return 不是一个可行的结果。
例如，如果没有安装图像编辑软件，查询 .jpg 或 .png 扩展名的可执行文件可能 return:
C:\Program Files (x86)\Windows Photo Viewer\PhotoViewer.dll
在这种情况下，使用AssociationQuery.Command作为参数来获取关联的命令行，然后可以将其传递给Process.Start()。
所以，在同样的情况下，结果将是：
C:\Windows\System32\rundll32.exe "C:\Program Files (x86)\Windows Photo
Viewer\PhotoViewer.dll", ImageView_Fullscreen %1
其中 %1 表示要打开的文件的名称。
在将此参数分配给 ProcessStartInfo.Arguments 属性.
之前，必须将其替换为文件路径
使用与可执行文件关联的文件扩展名（此处为 MS Word 的 .docx 扩展名）和与 DLL 组件关联的文件扩展名（ .png 扩展名，如果用户或程序安装没有关联其他 viewer/editor，则通常与预定义的系统小程序关联）。
As seen in the example, the File Names don't need to specify an
extension: the associated program can identify and decode the file
content in any case (i.e., the extension doesn't define the file format):
Dim FileName = "C:\Files\Docs\SomeDoc"
'Dim FileName = "C:\Files\Images\SomeImage"
Dim execProgram As String = FileExtentionInfo(AssociationQuery.Executable, "docx")
'Dim execProgram As String = FileExtentionInfo(AssociationQuery.Executable, "png")
Dim execExtension = Path.GetExtension(execProgram).ToLower()
Dim pInfo As ProcessStartInfo = New ProcessStartInfo()
If execExtension.Contains("exe") Then
pInfo.FileName = execProgram
pInfo.Arguments = FileName
Else
Dim rundllCmd As String = FileExtentionInfo(AssociationQuery.Command, "png")
Dim rundllParts = rundllCmd.Split({ChrW(32) + ChrW(34)}, StringSplitOptions.None)
pInfo.FileName = rundllParts(0)
pInfo.Arguments = ChrW(34) & rundllParts(1).Replace("%1", FileName)
End If
pInfo.UseShellExecute = False
Process.Start(pInfo)
声明：
VB.Net DllImport AssocQueryString()。参见 MSDN AssocQueryString function
<DllImport("Shlwapi.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Public Shared Function AssocQueryString(flags As AssocFlags, str As AssociationQuery,
pszAssoc As String, pszExtra As String, <Out> pszOut As System.Text.StringBuilder,
<[In]> <Out> ByRef pcchOut As UInteger) As UInteger
End Function
及其枚举：参见 MSDN ASSOCF enumeration, ASSOCSTR enumeration
<Flags> _
Public Enum AssocFlags
None = &H0 'No option selected
Init_NoRemapCLSID = &H1 'Instructs the interface methods not to map CLSID values to ProgID values.
Init_ByExeName = &H2 'THe pszAssoc parameter is an executable file name: the root key for search is set to the executable file's ProgID.
Open_ByExeName = &H2 'Alias for Init_ByExeName
Init_DefaultToStar = &H4 'If the value is not found under the root key, it should retrieve the comparable value from the * subkey.
Init_DefaultToFolder = &H8 'If the value is not found under the root key, it should retrieve the comparable value from the Folder subkey.
NoUserSettings = &H10 'Only the HKEY_CLASSES_ROOT should be searched, HKEY_CURRENT_USER should be ignored.
NoTruncate = &H20 'The return string should not be truncated. Return an error value and the required size for the complete string.
Verify = &H40 'Instructs to verify that data is accurate. This setting allows to read data from the user's hard disk for verification.
RemapRunDll = &H80 'Instructs to ignore Rundll.exe and return information about its target.
NoFixUps = &H100 'Instructs not to fix errors in the registry, such as the friendly name of a function not matching the one found in the .exe file.
IgnoreBaseClass = &H200 'Specifies that the BaseClass value should be ignored.
IgnoreUnknown = &H400 'Windows 7: "Unknown" ProgID should be ignored; instead, fail.
InitFixedProgid = &H800 'Windows 8: The supp. ProgID should be mapped using the sys defaults, rather than the current user defaults.
IsProtocol = &H1000 'Windows 8: The value is a protocol, should be mapped using the current user defaults.
InitForFile = &H2000 'Windows 8.1: The ProgID corresponds with a file extension based association. Use together with InitFixedProgid.
End Enum
Public Enum AssociationQuery
Command = 1, 'A command string associated with a Shell verb (=> Open, Edit, Print, New).
Executable, 'An executable from a Shell verb command string. Not all associations have executables.
FriendlyDocName, 'The friendly name of a document type. (Microsoft Office 2016 Document)
FriendlyAppName, 'The friendly name of an executable file. (Microsoft Office Word)
NoOpen, 'Ignore the information associated with the open subkey.
ShellNewValue, 'Look under the ShellNew subkey.
DDECommand, 'A template for DDE commands.
DDEIfExec, 'The DDE command to use to create a process.
DDEApplication, 'The application name in a DDE broadcast.
DDETopic, 'The topic name in a DDE broadcast.
Infotip, 'The InfoTip registry value. Returns an info tip for an item from which to create an info tip, such as when hovering the cursor over a file name.
Quicktip, 'Corresponds to the QuickTip registry value. Similar to InfoTip, but more suitable for network transport.
TileInfo, 'Corresponds to the TileInfo registry value. Similar to InfoTip, for a file type in a window that is in tile view.
ContentType, 'Describes a general type of MIME file association, such as image and bmp, to make general assumptions about a specific file type.
DefaultIcon, 'Returns the path to the default icon for this association. Positive numbers: index of the dll's resource table, Negative numbers: resource ID.
ShellExtension, 'If a Shell extension is associated, use this to get the CLSID of the Shell extension object, passing the string of the IID as the pwszExtra parameter.
DropTarget, 'For a verb invoked through COM and the IDropTarget interface, use this flag to get the IDropTarget object's CLSID. The verb is specified in the pwszExtra parameter.
DelegateExecute, 'For a verb invoked through COM and the IExecuteCommand interface, use this flag to get the IExecuteCommand object's CLSID. This CLSID is registered in the verb's command subkey as the DelegateExecute entry. The verb is specified in the pwszExtra parameter.
SupportedURIProtocols, 'Windows 8
ProgID, 'The ProgID provided by the app associated with the file type or URI scheme. This if configured by users in their default program settings.
AppID, 'The AppUserModelID of the app associated with the file type or URI scheme. This is configured by users in their default program settings.
AppPublisher, 'The publisher of the app associated with the file type or URI scheme. This is configured by users in their default program settings.
AppIconReference, 'The icon reference of the app associated with the file type or URI scheme. This is configured by users in their default program settings.
Max 'The maximum defined ASSOCSTR value, used for validation purposes.
End Enum
我们已经知道 System.Diagnostics.Process.Start("C:\filename.png") 是如何工作的，但是如果文件名不以扩展名结尾怎么办？
如何使用与 .png 扩展名关联的默认程序 运行 没有扩展名的文件名？
类似于：
openFile("C:\filename","PNG")
您当然可以将文件名和扩展名拼凑在一起，希望最好。
或者测试文件扩展名是否具有预定义的 Opener，注册表中的一个条目将扩展名与可以处理该文件格式的应用程序相关联。
系统提供了一个 API - AssocQueryString - 来提供此信息（当然，您也可以手动查找注册表，但情况可能会发生变化，并且 API 功能已经知道了）。 它也可以用于其他一些任务。
查看声明部分以找到 VB.Net 函数调用和相关的枚举数。
此辅助方法仅允许调用 API 函数而无需指定特殊标志。您只需定义要检索的信息类型。
例如：
AssociationQuery.Executable:
returns 与指定扩展关联的可执行文件的完整路径。
AssociationQuery.Command:
returns Rundll32 命令，当文件扩展名不直接与独立可执行文件关联，而是与 dll 或系统小程序关联时，Shell 执行该命令。
或者 return 与 Shell 动词关联的命令（打开、打印、编辑、新建等）。
AssociationQuery.FriendlyDocName:
returns 关联文件类型的友好名称。例如，.docx 扩展名将 return Microsoft Word 文档（取决于本地语言）。
AssociationQuery.FriendlyAppName:
returns 关联应用程序的友好名称。例如，.docx 扩展名将 return Word 2016（取决于本地语言）。
有关这些开关的更多信息以及声明部分中其他可用开关的说明，请参见下面的示例。
helper 方法（如下所述调用此方法）：
Public Function FileExtentionInfo(AssociationType As AssociationQuery, Extension As String) As String
If (Extension.Length <= 1) OrElse Not Extension.StartsWith(".") Then
Return String.Empty
Else
Dim flags As AssocFlags = AssocFlags.NoTruncate Or AssocFlags.RemapRunDll
Return ShellExtensionInfo(True, AssociationType, flags, Extension)
End If
End Function
worker方法：
Private Function ShellExtensionInfo(Verify As Boolean, AssociationType As AssociationQuery, flags As AssocFlags, Extension As String) As String
Dim pcchOut As UInteger = 0
flags = flags Or (If(Verify, AssocFlags.Verify, AssocFlags.IgnoreUnknown))
AssocQueryString(flags, AssociationType, Extension, Nothing, Nothing, pcchOut)
If pcchOut = 0 Then
Return String.Empty
Else
Dim pszOut As New StringBuilder(CType(pcchOut, Integer))
AssocQueryString(flags, AssociationType, Extension, Nothing, pszOut, pcchOut)
Return pszOut.ToString()
End If
End Function
要得到结果，只需调用辅助函数，询问你想要什么样的信息或关联(AssociationQuery)。
例如，这个调用：
Dim Executable As String = FileExtentionInfo(AssociationQuery.Executable, ".docx")
可以return（取决于安装的软件和用户的选择）：
C:\Program Files\Microsoft Office\Office16\WINWORD.EXE
如前所述，并非所有扩展都有关联的可执行文件。某些文件扩展名可能映射到由 Rundll32.exe 启动的系统 applet/tool。
在这种情况下，使用 AssociationQuery.Executable 作为参数可能 return 不是一个可行的结果。
例如，如果没有安装图像编辑软件，查询 .jpg 或 .png 扩展名的可执行文件可能 return:
C:\Program Files (x86)\Windows Photo Viewer\PhotoViewer.dll
在这种情况下，使用AssociationQuery.Command作为参数来获取关联的命令行，然后可以将其传递给Process.Start()。
所以，在同样的情况下，结果将是：
C:\Windows\System32\rundll32.exe "C:\Program Files (x86)\Windows Photo Viewer\PhotoViewer.dll", ImageView_Fullscreen %1
其中 %1 表示要打开的文件的名称。
在将此参数分配给 ProcessStartInfo.Arguments 属性.
使用与可执行文件关联的文件扩展名（此处为 MS Word 的 .docx 扩展名）和与 DLL 组件关联的文件扩展名（ .png 扩展名，如果用户或程序安装没有关联其他 viewer/editor，则通常与预定义的系统小程序关联）。
As seen in the example, the File Names don't need to specify an extension: the associated program can identify and decode the file content in any case (i.e., the extension doesn't define the file format):
Dim FileName = "C:\Files\Docs\SomeDoc"
'Dim FileName = "C:\Files\Images\SomeImage"
Dim execProgram As String = FileExtentionInfo(AssociationQuery.Executable, "docx")
'Dim execProgram As String = FileExtentionInfo(AssociationQuery.Executable, "png")
Dim execExtension = Path.GetExtension(execProgram).ToLower()
Dim pInfo As ProcessStartInfo = New ProcessStartInfo()
If execExtension.Contains("exe") Then
pInfo.FileName = execProgram
pInfo.Arguments = FileName
Else
Dim rundllCmd As String = FileExtentionInfo(AssociationQuery.Command, "png")
Dim rundllParts = rundllCmd.Split({ChrW(32) + ChrW(34)}, StringSplitOptions.None)
pInfo.FileName = rundllParts(0)
pInfo.Arguments = ChrW(34) & rundllParts(1).Replace("%1", FileName)
End If
pInfo.UseShellExecute = False
Process.Start(pInfo)
声明：
VB.Net DllImport AssocQueryString()。参见 MSDN AssocQueryString function
<DllImport("Shlwapi.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Public Shared Function AssocQueryString(flags As AssocFlags, str As AssociationQuery,
pszAssoc As String, pszExtra As String, <Out> pszOut As System.Text.StringBuilder,
<[In]> <Out> ByRef pcchOut As UInteger) As UInteger
End Function
及其枚举：参见 MSDN ASSOCF enumeration, ASSOCSTR enumeration
<Flags> _
Public Enum AssocFlags
None = &H0 'No option selected
Init_NoRemapCLSID = &H1 'Instructs the interface methods not to map CLSID values to ProgID values.
Init_ByExeName = &H2 'THe pszAssoc parameter is an executable file name: the root key for search is set to the executable file's ProgID.
Open_ByExeName = &H2 'Alias for Init_ByExeName
Init_DefaultToStar = &H4 'If the value is not found under the root key, it should retrieve the comparable value from the * subkey.
Init_DefaultToFolder = &H8 'If the value is not found under the root key, it should retrieve the comparable value from the Folder subkey.
NoUserSettings = &H10 'Only the HKEY_CLASSES_ROOT should be searched, HKEY_CURRENT_USER should be ignored.
NoTruncate = &H20 'The return string should not be truncated. Return an error value and the required size for the complete string.
Verify = &H40 'Instructs to verify that data is accurate. This setting allows to read data from the user's hard disk for verification.
RemapRunDll = &H80 'Instructs to ignore Rundll.exe and return information about its target.
NoFixUps = &H100 'Instructs not to fix errors in the registry, such as the friendly name of a function not matching the one found in the .exe file.
IgnoreBaseClass = &H200 'Specifies that the BaseClass value should be ignored.
IgnoreUnknown = &H400 'Windows 7: "Unknown" ProgID should be ignored; instead, fail.
InitFixedProgid = &H800 'Windows 8: The supp. ProgID should be mapped using the sys defaults, rather than the current user defaults.
IsProtocol = &H1000 'Windows 8: The value is a protocol, should be mapped using the current user defaults.
InitForFile = &H2000 'Windows 8.1: The ProgID corresponds with a file extension based association. Use together with InitFixedProgid.
End Enum
Public Enum AssociationQuery
Command = 1, 'A command string associated with a Shell verb (=> Open, Edit, Print, New).
Executable, 'An executable from a Shell verb command string. Not all associations have executables.
FriendlyDocName, 'The friendly name of a document type. (Microsoft Office 2016 Document)
FriendlyAppName, 'The friendly name of an executable file. (Microsoft Office Word)
NoOpen, 'Ignore the information associated with the open subkey.
ShellNewValue, 'Look under the ShellNew subkey.
DDECommand, 'A template for DDE commands.
DDEIfExec, 'The DDE command to use to create a process.
DDEApplication, 'The application name in a DDE broadcast.
DDETopic, 'The topic name in a DDE broadcast.
Infotip, 'The InfoTip registry value. Returns an info tip for an item from which to create an info tip, such as when hovering the cursor over a file name.
Quicktip, 'Corresponds to the QuickTip registry value. Similar to InfoTip, but more suitable for network transport.
TileInfo, 'Corresponds to the TileInfo registry value. Similar to InfoTip, for a file type in a window that is in tile view.
ContentType, 'Describes a general type of MIME file association, such as image and bmp, to make general assumptions about a specific file type.
DefaultIcon, 'Returns the path to the default icon for this association. Positive numbers: index of the dll's resource table, Negative numbers: resource ID.
ShellExtension, 'If a Shell extension is associated, use this to get the CLSID of the Shell extension object, passing the string of the IID as the pwszExtra parameter.
DropTarget, 'For a verb invoked through COM and the IDropTarget interface, use this flag to get the IDropTarget object's CLSID. The verb is specified in the pwszExtra parameter.
DelegateExecute, 'For a verb invoked through COM and the IExecuteCommand interface, use this flag to get the IExecuteCommand object's CLSID. This CLSID is registered in the verb's command subkey as the DelegateExecute entry. The verb is specified in the pwszExtra parameter.
SupportedURIProtocols, 'Windows 8
ProgID, 'The ProgID provided by the app associated with the file type or URI scheme. This if configured by users in their default program settings.
AppID, 'The AppUserModelID of the app associated with the file type or URI scheme. This is configured by users in their default program settings.
AppPublisher, 'The publisher of the app associated with the file type or URI scheme. This is configured by users in their default program settings.
AppIconReference, 'The icon reference of the app associated with the file type or URI scheme. This is configured by users in their default program settings.
Max 'The maximum defined ASSOCSTR value, used for validation purposes.
End Enum