how to update Visual Studio UI when using DynamicItemStart inside a vsix package

问题

I'm implementing a DynamicItemStart button inside a Menu Controller. I'm loading the dynamic items for this button when Visual Studio starts. Everything is loaded correctly so the initialize method is called an I see all the new items in this Dynamic button. After the package is completely loaded I want to add more items to this Dynamic button, but since the package is already loaded the initialize method is not called again and I cannot see the new items in this Dynamic button. I only see the ones that were loaded when VS started.

Is there any way that I can force the update of this Dynamic button so it shows the new items?. I want to be able to update the VS UI after I added more items but outside the Initialize method. The implementation I did is very similar to the one showed on this msdn example:

http://msdn.microsoft.com/en-us/library/bb166492.aspx

Does anyone know if an Update of the UI can be done by demand?

Any hints are greatly appreciated.

回答1:

I finally got this working. The main thing is the implementation of a derived class of OleMenuCommand that implements a new constructor with a Predicate. This predicate is used to check if a new command is a match within the DynamicItemStart button.

public class DynamicItemMenuCommand : OleMenuCommand
{
private Predicate<int> matches;
public DynamicItemMenuCommand(CommandID rootId, Predicate<int> matches, EventHandler invokeHandler, EventHandler beforeQueryStatusHandler)
  : base(invokeHandler, null, beforeQueryStatusHandler, rootId)
{
  if (matches == null)
  {
    throw new ArgumentNullException("Matches predicate cannot be null.");
  }

  this.matches = matches;
}


public override bool DynamicItemMatch(int cmdId)
{
  if (this.matches(cmdId))
  {
    this.MatchedCommandId = cmdId;
    return true;
  }

  this.MatchedCommandId = 0;
  return false;      
}

}

The above class should be used when adding the commands on execution time. Here's the code that creates the commands

public class ListMenu
{
 private int _baselistID = (int)PkgCmdIDList.cmdidMRUList;    
 private List<IVsDataExplorerConnection> _connectionsList;


public ListMenu(ref OleMenuCommandService mcs)
{             
  InitMRUMenu(ref mcs);
}    

internal void InitMRUMenu(ref OleMenuCommandService mcs)
{            
  if (mcs != null)
  {               
    //_baselistID has the guid value of the DynamicStartItem 
    CommandID dynamicItemRootId = new CommandID(GuidList.guidIDEToolbarCmdSet, _baselistID);
    DynamicItemMenuCommand dynamicMenuCommand = new DynamicItemMenuCommand(dynamicItemRootId,      isValidDynamicItem, OnInvokedDynamicItem, OnBeforeQueryStatusDynamicItem);
          mcs.AddCommand(dynamicMenuCommand);                  
  }
}

private bool IsValidDynamicItem(int commandId)    
{      
  return ((commandId - _baselistID) < connectionsCount);  // here is the place to put the criteria to add a new command to the dynamic button
}


private void OnInvokedDynamicItem(object sender, EventArgs args)
{
  DynamicItemMenuCommand invokedCommand = (DynamicItemMenuCommand)sender;      

  if (null != invokedCommand)
  {
     .....
  }
}

private void OnBeforeQueryStatusDynamicItem(object sender, EventArgs args)
{
  DynamicItemMenuCommand matchedCommand = (DynamicItemMenuCommand)sender;           

  bool isRootItem = (matchedCommand.MatchedCommandId == 0);
    matchedCommand.Enabled = true;
    matchedCommand.Visible = true;
    int indexForDisplay = (isRootItem ? 0 : (matchedCommand.MatchedCommandId - _baselistID));
    matchedCommand.Text = "Text for the command";
  matchedCommand.MatchedCommandId = 0;
}  

}

I had to review a lot of documentation since it was not very clear how the commands can be added on execution time. So I hope this save some time whoever has to implement anything similar.

回答2:

The missing piece for me was figuring out how to control the addition of new items.

It took me some time to figure out that the matches predicate (the IsValidDynamicItem method in the sample) controls how many items get added - as long as it returns true, the OnBeforeQueryStatusDynamicItem gets invoked and can set the details (Enabled/Visible/Checked/Text etc.) of the match to be added to the menu.

来源：https://stackoverflow.com/questions/22032154/how-to-update-visual-studio-ui-when-using-dynamicitemstart-inside-a-vsix-package