How to: Export Settings By Using Interop Assemblies
A VSPackage may export settings from the Visual Studio integrated development environment (IDE). The IDE uses a VSPackage's implementation of the IVsUserSettings interface. If the package also provides the IVsUserSettingsQuery interface, then the IVsUserSettingsQuery interface is used to determine how the VSPackage's configuration is to be saved.
Note
The Managed Package Framework (MPF) provides a set of managed classes to facilitate the creation of Visual Studio extensions. To perform this task using the MPF, see How to: Export Settings By Using the Managed Package Framework.
To implement settings export on a VSPackage
Implement basic support for the Visual Studio settings mechanism.
Register the VSPackage as supporting the settings mechanism by defining one or more Custom Settings Points.
For more information, see Persisting Settings.
Declare that the VSPackage implements IVsUserSettings. If desired, the VSPackage can also implement IVsUserSettingsQuery interface. For example:
public class MyPackage : IVsPackage, IVsUserSettings, IVsUserSettingsQueryEnsure that the VSPackage's implementation of the QueryInterface method supplies an IVsUserSettings interface when called with IID_IVsUserSettings.
Optionally, QueryInterface can supply an IVsUserSettingsQuery interface when called with the IID_IVsUserSettingsQuery interface.
STDMETHODIMP MyPackage::QueryInterface(THIS_ REFIID riid, LPVOID FAR* ppvObj) { if (ppvObj == NULL) return E_POINTER; *ppvObj = NULL; if (riid == IID_IUnknown) *ppvObj = (LPVOID)(IUnknown *)(IClassFactory*)this; else if (riid == IID_IClassFactory) *ppvObj = (LPVOID)(IClassFactory *)this; else if (riid == IID_IVsPackage) *ppvObj = (LPVOID)(IVsPackage *)this; else if (riid == IID_IVsPersistSolutionOpts) *ppvObj = (LPVOID)(IVsPersistSolutionOpts *)this; else if (riid == IID_IVsPersistSolutionProps) *ppvObj = (LPVOID)(IVsPersistSolutionProps *)this; else if (riid == IID_IVsComponentSelectorProvider) *ppvObj = (LPVOID)(IVsComponentSelectorProvider *)this; else if (riid == IID_IVsUserSettings) *ppvObj = (LPVOID)(IVsUserSettings *)this; else if (riid == IID_IVsUserSettingsQuery) *ppvObj = (LPVOID)(IVsUserSettingsQuery *)this; if (*ppvObj) { AddRef(); return NOERROR; } return E_NOINTERFACE; }
Optionally, alert the IDE of the need to export a particular setting.
A VSPackage can choose to conditionally save a setting that the Custom Settings Point state defines. For example, save only if the user explicitly indicates a setting to be saved.
In this case, the IVsUserSettingsQuery interface must be implemented.
If a VSPackage does not implement IVsUserSettingsQuery, all its state information is saved during a settings export.
A VSPackage can support more than one Custom Settings Point (settings category). Implementations of the NeedExport method must check the supplied Custom Settings Point's GUID or settings category argument to determine if a particular group of settings must be saved.
In the example below, the VSPackage always requests that its command bar state is saved, but only requests that its key binding state is saved if a flag has been set.
Write settings data to the settings file.
To support exporting settings, a VSPackage must always implement the ExportSettings method.
The implementation must handle the arguments passed by the IDE, the GUID of that Custom Settings Point's category, and an IVsSettingsWriter interface.
A VSPackage can support more than one Custom Settings Point (settings category). In the example below, the ExportSettings method calls a different implementation for persisting command bar state as opposed to persisting key binding state.
A VSPackage must use the supplied IVsSettingsWriter interface to save data to the setting file.
interface IVsSettingsWriter : IUnknown
{
HRESULT WriteSettingString( LPCOLESTR pszSettingName, LPCOLESTR pszSettingValue);
HRESULT WriteSettingLong( LPCOLESTR pszSettingName, long lSettingValue);
HRESULT WriteSettingBoolean( LPCOLESTR pszSettingName, BOOL fSettingValue);
HRESULT WriteSettingBytes( LPCOLESTR pszSettingName, BYTE *pSettingValue, long lDataLength);
HRESULT WriteSettingAttribute( LPCOLESTR pszSettingName, LPCOLESTR pszAttributeName, LPCOLESTR pszSettingValue);
HRESULT WriteSettingXml( IUnknown *pIXMLDOMNode);
HRESULT WriteSettingXmlFromString( LPCOLESTR szXML);
HRESULT ReportError( LPCOLESTR pszError, VSSETTINGSERRORTYPES dwErrorType);
};
The value of the pszSettingName argument supplied to an IVsSettingsWriter interface must uniquely identify each data element saved within a settings category.
Note
Names must be unique within a Custom Settings Point because the IDE uses its GUID and the value of pszSettingName to identify each saved setting. If more than one IVsSettingsWriter method is called with the same value of pszSettingName, the original value is overwritten in the settings file.
The settings file supports random data access. Consequently, the order of read and write settings operations is not important.
This is illustrated in the implementations of exporting and importing command bar state (ExportSettings_CommandBar and ImportSettings_CommandBar) in the example below.
If the implementation can map data into one of the four supported formats, there is no restriction on how much or what type of data can be written.
Note
In addition to data explicitly written and transparent to the ExportSettings implementation, the settings API also saves Visual Studio version information. Saved settings can be compared against the version of the IDE that generated them during settings import.
Example
The following example demonstrates how to import and export settings data.
// --------------------------------------------------------------------------
// IVsUserSettings methods used for configuration export.
// Delegate to the right shell object based on the category GUID.
// --------------------------------------------------------------------------
static const WCHAR c_szFirstSettingName[] = L"FirstSettingName";
static const WCHAR c_szRandomTrashBytes[] = L"RandomTrashBytes";
static const WCHAR c_szRandomTrashLength[] = L"RandomTrashLength";
static const WCHAR c_szBreakPointWindow[] = L"Breakpoints Window";
// Export Settings.
STDMETHOD(NeedExport)(WCHAR* pszCategoryGUID, BOOL *pfNeedExport)
{
if (!pfNeedExport)
return E_INVALIDARG;
CLSID clsidCategory;
HRESULT hr= S_OK;
hr = CLSIDFromString(pszCategoryGUID, &clsidCategory);
IfFailGo(hr);
if (GUID_Profiles_CommandBars == clsidCategory) {
*pfNeedExport = TRUE; //Always export Command Bar Configuration
}else if (GUID_Profiles_KeyBindings == clsidCategory) {
*pfNeedExport = FALSE; //By Default don't export key bindings
if (m_fMake_Permanent)
*pfNeedExport = TRUE; //Export if user wants current configuration saved.
}else{
hr = E_UNEXPECTED;
}
Error:
return hr;
}
STDMETHOD(ExportSettings)(WCHAR *pszCategoryGUID, IVsSettingsWriter *pSettings)
{
CLSID clsidCategory;
HRESULT hr;
hr = CLSIDFromString(pszCategoryGUID, &clsidCategory);
IfFailGo(hr);
// Delegate to the right internal implementation based on
// the requested category.
if (GUID_Profiles_CommandBars == clsidCategory) {
hr = ExportSettings_CommandBars(pSettings);
}else if (GUID_Profiles_KeyBindings == clsidCategory) {
hr = ExportSettings_KeyBindings(pSettings);
}else{
hr = E_UNEXPECTED;
}
Error:
return hr;
};
HRESULT ExportSettings_CommandBars(IVsSettingsWriter *pSettings)
{
if (!pSettings)
return E_INVALIDARG;
hr = pSettings->WriteSettingString(c_szFirstSettingName, L"Value1");
IfFailGo(hr);
int cRandomTrash = 12345;
BYTE *pRandomTrash = (BYTE *)VSAlloc(cRandomTrash);
if (pRandomTrash){
hr = pSettings->WriteSettingBytes(c_szRandomTrashBytes, pRandomTrash, cRandomTrash);
IfFailGo(hr);
hr = pSettings->WriteSettingLong(c_szRandomTrashLength, cRandomTrash);
IfFailGo(hr);
}
Error:
return hr;
};
HRESULT ExportSettings_KeyBindings(IVsSettingsWriter *pSettings)
{
if (!pSettings)
return E_INVALIDARG;
hr = pSettings->WriteSettingString(c_szBreakPointWindow, L"Ctrl + Alt + B");
IfFailGo(hr);
Error:
return hr;
};
STDMETHOD(ImportSettings)(WCHAR *pszCategoryGUID, IVsSettingsReader *pSettings, UserSettingsFlags flags, BOOL *pfRestartRequired)
{
CLSID clsidCategory;
HRESULT hr;
hr = CLSIDFromString(pszCategoryGUID, &clsidCategory);
IfFailGo(hr);
// Delegate to the right internal implementation based on
// the requested category.
if (GUID_Profiles_CommandBars == clsidCategory)
{
hr = ImportSettings_CommandBars(, pSettings, flags, pfRestartRequired);
}
else if (GUID_Profiles_KeyBindings == clsidCategory)
{
hr = ImportSettings_KeyBindings( pSettings, flags, pfRestartRequired);
}
else
{
hr = E_UNEXPECTED;
}
Error:
return hr;
};
// Import Settings.
HRESULT ImportSettings_CommandBars(IVsSettingsReader *pSettings, UserSettingsFlags flags, BOOL *pfRestartRequired)
{
if (!pSettings)
return E_INVALIDARG;
if (pfRestartRequired)
{
*pfRestartRequired = FALSE; //Nobody should require a restart!!
}
CComBSTR bstrFirstSettingName;
long lTrashLength = 0;
BYTE *pTrashBytes = NULL;
// Determines whether to treat import as an additive operation, or a reset all settings operation.
BOOL fResetCompletely = FALSE;
if (flags & USF_ResetOnImport)
fResetCompletely = TRUE;
hr = pSettings->ReadSettingString(c_szFirstSettingName, &bstrFirstSettingName);
IfFailGo(hr);
hr = pSettings->ReadSettingLong(c_szRandomTrashLength, &lTrashLength);
IfFailGo(hr);
if (lTrashLength > 0)
{
pTrashBytes = (BYTE*)VSAlloc(lTrashLength);
IfNullMemGo(pTrashBytes);
long lDataRead = 0;
hr = pSettings->ReadSettingBytes(c_szRandomTrashLength, pTrashBytes, &lDataRead, lTrashLength);
IfFailGo(hr);
if (lDataRead != lTrashLength)
{
hr = E_UNEXPECTED;
goto Error;
}
}
// Note: before returning, these settings should immediately
// be applied to your personal settings store,
// whether in the registry or the file system.
// This write-through cache methodology is essential to to work
// in multi-instance IDE scenarios.
hr = UpdateState_CommandBar(bstrFirstSettingName,lTrashLength,pTrashBytes,lDataRead);
Error:
return hr;
};
HRESULT ImportSettings_KeyBindings(IVsSettingsReader *pSettings, UserSettingsFlags flags, BOOL *pfRestartRequired)
{
if (!pSettings)
return E_INVALIDARG;
if (pfRestartRequired)
{
*pfRestartRequired = FALSE; //Nobody should require a restart!!
}
CComBSTR bstrBreakPointWindow;
// Determines whether import can be treated as an additive
// operation, or a reset all settings operation.
BOOL fResetCompletely = FALSE;
if (flags & USF_ResetOnImport)
fResetCompletely = TRUE;
hr = pSettings->ReadSettingString(c_szBreakPointWindow, &bstrBreakPointWindow);
IfFailGo(hr);
// Note: Before returning, these settings should immediately
// be applied to your personal settings
// store, whether in the registry or the file system.
// This write-through cache methodology is essential to allow us
// to work in multi-instance IDE scenarios.
hr = UpdateState_KeyBindings(bstrBreakPointWindow);
Error:
return hr;
}
See Also
Tasks
How to: Use Interop Assemblies to Import Settings
Concepts
Customizing Development Settings in Visual Studio