Extending theTask List
The Visual Studio Task List lets users add custom programming tasks, view task comments that link to lines in the code, and create and view custom categories for task messages.
Tasks are handled through a service named SVsTaskList, which implements IVsTaskList and IVsTaskList2. To use basic Task List functionality, you must create a task provider by implementing IVsTaskProvider.
Register your task provider with the SVsTaskList service by calling RegisterTaskProvider, which returns a cookie value that must be used to uniquely identify the task provider in all subsequent transactions.
Every task provider implementation is responsible for maintaining an internal list of tasks. The task provider can call RefreshTasks on Task List to update the displayed list of tasks. When this occurs:
The service calls back into the task provider by using the EnumTaskItems method.
The task provider implementation of EnumTaskItems returns an IVsEnumTaskItems object.
The IVsEnumTaskItems object iterates over a collection of IVsTaskItem objects.
The SVsTaskList service then updates the Task List display.
Additional functionality is available. The IVsTaskProvider3 interface enables every task provider to supply its own custom set of columns.
Example
The following code example shows an implementation of a task provider.
Class TaskProvider
Implements ITaskProvider
Implements IVsSolutionEvents
Public Sub New(ByVal provider As IServiceProvider)
_imageList.ImageSize = New Size(9, 16)
_imageList.Images.AddStrip(Resources.priority)
_imageList.TransparentColor = Color.FromArgb(0, 255, 0)
_serviceProvider = provider
Dim taskList As IVsTaskList = TryCast(_serviceProvider.GetService(GetType(SVsTaskList)), IVsTaskList)
Dim hr As Integer = taskList.RegisterTaskProvider(Me, _cookie)
Debug.Assert(hr = VSConstants.S_OK, "RegisterTaskProvider did not return S_OK.")
Debug.Assert(_cookie <> 0, "RegisterTaskProvider did not return a nonzero cookie.")
SetCommandHandlers()
ListenForProjectUnload()
End Sub
#Region "ITaskProvider Members"
Public Sub AddResult(ByVal result As IScanResult, ByVal projectFile As String)
Dim fullPath As String = result.FilePath
If Not Path.IsPathRooted(fullPath) Then
fullPath = Utilities.AbsolutePathFromRelative(fullPath, Path.GetDirectoryName(projectFile))
End If
If result.Scanned Then
For Each hit As IScanHit In result.Results
If hit.Warning IsNot Nothing AndAlso hit.Warning.Length > 0 Then
' See if we've warned about this term before;
' if so, don't warn again.
If _termsWithDuplicateWarning.Find(Function(ByVal item As String) [String].Compare(item, hit.Term.Text, StringComparison.OrdinalIgnoreCase) = 0) Is Nothing Then
_tasks.Add(New Task(hit.Term.Text, hit.Term.Severity, hit.Term.[Class], hit.Warning, "", "", _
-1, -1, "", "", Me, _serviceProvider))
_termsWithDuplicateWarning.Add(hit.Term.Text)
End If
End If
_tasks.Add(New Task(hit.Term.Text, hit.Term.Severity, hit.Term.[Class], hit.Term.Comment, hit.Term.RecommendedTerm, fullPath, _
hit.Line, hit.Column, projectFile, hit.LineText, Me, _serviceProvider))
Next
Else
_tasks.Add(New Task("", 1, "", [String].Format(CultureInfo.CurrentUICulture, Resources.FileNotScannedError, fullPath), "", fullPath, _
-1, -1, projectFile, "", Me, _serviceProvider))
End If
Refresh()
End Sub
Public Sub Clear()
_tasks.Clear()
Refresh()
End Sub
Public Sub SetAsActiveProvider()
Dim taskList As IVsTaskList2 = TryCast(_serviceProvider.GetService(GetType(SVsTaskList)), IVsTaskList2)
Dim ourGuid As Guid = _providerGuid
Dim hr As Integer = taskList.SetActiveProvider(ourGuid)
Debug.Assert(hr = VSConstants.S_OK, "SetActiveProvider did not return S_OK.")
End Sub
Public Sub ShowTaskList()
Dim shell As IVsUIShell = TryCast(_serviceProvider.GetService(GetType(SVsUIShell)), IVsUIShell)
Dim dummy As Object = Nothing
Dim cmdSetGuid As Guid = VSConstants.GUID_VSStandardCommandSet97
Dim hr As Integer = shell.PostExecCommand(cmdSetGuid, CInt(VSConstants.VSStd97CmdID.TaskListWindow), 0, dummy)
Debug.Assert(hr = VSConstants.S_OK, "SetActiveProvider did not return S_OK.")
End Sub
''' <summary>
''' Returns an image index between 0 and 2 inclusive corresponding
''' to the specified severity.
''' </summary>
Public Shared Function GetImageIndexForSeverity(ByVal severity As Integer) As Integer
Return Math.Max(1, Math.Min(3, severity)) - 1
End Function
Public ReadOnly Property IsShowingIgnoredInstances() As Boolean
Get
Return _showingIgnoredInstances
End Get
End Property
#End Region
#Region "IVsTaskProvider Members"
Public Function EnumTaskItems(ByRef ppenum As IVsEnumTaskItems) As Integer
ppenum = New TaskEnumerator(_tasks, IsShowingIgnoredInstances)
Return VSConstants.S_OK
End Function
<DllImport("comctl32.dll")> _
Private Shared Function ImageList_Duplicate(ByVal original As IntPtr) As IntPtr
End Function
Public Function ImageList(ByRef phImageList As IntPtr) As Integer
phImageList = ImageList_Duplicate(_imageList.Handle)
Return VSConstants.S_OK
End Function
Public Function OnTaskListFinalRelease(ByVal pTaskList As IVsTaskList) As Integer
If (_cookie <> 0) AndAlso (pTaskList IsNot Nothing) Then
Dim hr As Integer = pTaskList.UnregisterTaskProvider(_cookie)
Debug.Assert(hr = VSConstants.S_OK, "UnregisterTaskProvider did not return S_OK.")
End If
Return VSConstants.S_OK
End Function
Public Function ReRegistrationKey(ByRef pbstrKey As String) As Integer
pbstrKey = ""
Return VSConstants.E_NOTIMPL
End Function
Public Function SubcategoryList(ByVal cbstr As UInteger, ByVal rgbstr As String(), ByRef pcActual As UInteger) As Integer
pcActual = 0
Return VSConstants.E_NOTIMPL
End Function
End Class
class TaskProvider : ITaskProvider, IVsSolutionEvents
{
public TaskProvider(IServiceProvider provider)
{
_imageList.ImageSize = new Size(9, 16);
_imageList.Images.AddStrip(Resources.priority);
_imageList.TransparentColor = Color.FromArgb(0, 255, 0);
_serviceProvider = provider;
IVsTaskList taskList = _serviceProvider.GetService(typeof(SVsTaskList)) as IVsTaskList;
int hr = taskList.RegisterTaskProvider(this, out _cookie);
Debug.Assert(hr == VSConstants.S_OK, "RegisterTaskProvider did not return S_OK.");
Debug.Assert(_cookie != 0, "RegisterTaskProvider did not return a nonzero cookie.");
SetCommandHandlers();
ListenForProjectUnload();
}
#region ITaskProvider Members
public void AddResult(IScanResult result, string projectFile)
{
string fullPath = result.FilePath;
if (!Path.IsPathRooted(fullPath))
{
fullPath = Utilities.AbsolutePathFromRelative(fullPath, Path.GetDirectoryName(projectFile));
}
if (result.Scanned)
{
foreach (IScanHit hit in result.Results)
{
if (hit.Warning != null && hit.Warning.Length > 0)
{
// See if we've warned about this term before;
// if so, don't warn again.
if (null == _termsWithDuplicateWarning.Find(
delegate(string item)
{
return String.Compare(item, hit.Term.Text,
StringComparison.OrdinalIgnoreCase) == 0;
}))
{
_tasks.Add(new Task(hit.Term.Text,
hit.Term.Severity, hit.Term.Class, hit.Warning,
"", "", -1, -1, "", "", this, _serviceProvider));
_termsWithDuplicateWarning.Add(hit.Term.Text);
}
}
_tasks.Add(new Task(hit.Term.Text, hit.Term.Severity,
hit.Term.Class, hit.Term.Comment, hit.Term.RecommendedTerm, fullPath,
hit.Line, hit.Column, projectFile, hit.LineText, this,
_serviceProvider));
}
}
else
{
_tasks.Add(new Task("", 1, "", String.Format(CultureInfo.CurrentUICulture,
Resources.FileNotScannedError, fullPath), "", fullPath, -1, -1,
projectFile, "", this, _serviceProvider));
}
Refresh();
}
public void Clear()
{
_tasks.Clear();
Refresh();
}
public void SetAsActiveProvider()
{
IVsTaskList2 taskList = _serviceProvider.GetService(typeof(SVsTaskList)) as IVsTaskList2;
Guid ourGuid = _providerGuid;
int hr = taskList.SetActiveProvider(ref ourGuid);
Debug.Assert(hr == VSConstants.S_OK,
"SetActiveProvider did not return S_OK.");
}
public void ShowTaskList()
{
IVsUIShell shell = _serviceProvider.GetService(typeof(SVsUIShell)) as IVsUIShell;
object dummy = null;
Guid cmdSetGuid = VSConstants.GUID_VSStandardCommandSet97;
int hr = shell.PostExecCommand(ref cmdSetGuid, (int)VSConstants.VSStd97CmdID.TaskListWindow, 0, ref dummy);
Debug.Assert(hr == VSConstants.S_OK, "SetActiveProvider did not return S_OK.");
}
/// <summary>
/// Returns an image index between 0 and 2 inclusive corresponding
/// to the specified severity.
/// </summary>
public static int GetImageIndexForSeverity(int severity)
{
return Math.Max(1, Math.Min(3, severity)) - 1;
}
public bool IsShowingIgnoredInstances
{
get { return _showingIgnoredInstances; }
}
#endregion
#region IVsTaskProvider Members
public int EnumTaskItems(out IVsEnumTaskItems ppenum)
{
ppenum = new TaskEnumerator(_tasks, IsShowingIgnoredInstances);
return VSConstants.S_OK;
}
[DllImport("comctl32.dll")]
static extern IntPtr ImageList_Duplicate(IntPtr original);
public int ImageList(out IntPtr phImageList)
{
phImageList = ImageList_Duplicate(_imageList.Handle);
return VSConstants.S_OK;
}
public int OnTaskListFinalRelease(IVsTaskList pTaskList)
{
if ((_cookie != 0) && (null != pTaskList))
{
int hr = pTaskList.UnregisterTaskProvider(_cookie);
Debug.Assert(hr == VSConstants.S_OK, "UnregisterTaskProvider did not return S_OK.");
}
return VSConstants.S_OK;
}
public int ReRegistrationKey(out string pbstrKey)
{
pbstrKey = "";
return VSConstants.E_NOTIMPL;
}
public int SubcategoryList(uint cbstr, string[] rgbstr,
out uint pcActual)
{
pcActual = 0;
return VSConstants.E_NOTIMPL;
}
}
See Also
Creating Custom Task List Views
How to: Create Custom Categories of Task Lists