MFC search tree view based on label (name)

-
So I recently came across a need to use a tree view in an MFC based application. I also found I needed to search that tree based on the label (text displayed to the user). After some research I found an old link here at MSDN. However the article is almost 6 years old. MFC has changed a bit since then. So I had to change the code a bit to use all the new MFC macros for tree view usage. All these macros are also defined as functions on the CTreeCtrl class but doing it this way allows you to traverse any tree you want instead of being tied to a single instance. You can read more about the macros and treeviews here.

All items are passed in except for MAXTEXTLEN which needs to be defined somewhere and included for reference. Mine is set to 100 since we can get fairly long long names in our application.

The function:
HTREEITEM GetItemByName(   HWND hWnd, 
                 HTREEITEM hItem, 
                 LPCTSTR szItemName )
{
    try
    {
        // If hItem is NULL, start search from root item.
        if( hItem == NULL )
        {
            hItem = TreeView_GetRoot( hWnd );
        }//end if
        
        while( hItem != NULL )
        {
            TCHAR szBuffer[MAXTEXTLEN+1];
            TV_ITEM item;

            item.hItem = hItem;
            item.mask = TVIF_TEXT | TVIF_CHILDREN;
            item.pszText = szBuffer;
            item.cchTextMax = MAXTEXTLEN;

            TreeView_GetItem( hWnd, &item );
            
            // Did we find it?
            if( lstrcmp( item.pszText, szItemName ) == 0 )
            {
                return hItem;
            }//end if
            
            // Check whether we have child items.
            if( item.cChildren )
            {
                // Recursively traverse child items.
                HTREEITEM hItemFound, hItemChild;

                hItemChild = TreeView_GetChild( hWnd, hItem );
                
                hItemFound = GetItemByName( hWnd, hItemChild, szItemName );

                // Did we find it?
                if( hItemFound != NULL )
                {
                    return hItemFound;
                }//end if
            }//end if

            // Go to next sibling item.
            hItem = TreeView_GetNextSibling( hWnd, hItem );

        }//end while

        // Not found.
        return NULL;
    }//end try
    catch( CException* ex )
    {
        // TODO: add some logging here, etc
        delete ex;
        return NULL;
    }//end catch
}


The usage:

HTREEITEM hItem = GetItemByName( aTreeHWND, NULL, _T("SOME NAME") );
 
if( hItem != NULL )
{
   //TODO: SUCCESS!
}//end if
else
{
   // TODO: FAILURE! :(
}//end else

Comments

Post a Comment

Popular posts from this blog

String.Replace vs Regex.Replace

-
Image
I recently ran into a situation where I had to do some string manipulation. I had to replace some bad text with valid text. All this had to do with creating valid xml element names. So we had to string white space and some other invalid characters and replace them with valid xml element formatting. To do this we ended up using the Regex.Replace static method. Simply because there was some complexity involved that would have entailed using more then 1 String.Replace call when we can do it all with one regular expression. This caused some discussion about how heavy the regex class is and when to use it. I decided to do some testing and these are my results. First the code static void Main( string[] args ) { // this is our test value string testValue = "This is a test string"; int count; // run the regex replace DateTime regexStart = DateTime.Now; for( count = 0; count < 10000000; count++ ) { string newValue = Regex.Replace( testValue, ...
Read more

C# Producer Consumer using Rabbit MQ

-
So I've been learning about the different message queuing systems and discovered rabbit MQ, an open source and very popular message queuing system. I've created a very basic producer/consumer system that sends a message to a rabbit MQ queue. Producer/Consumer is pretty simple, you have two systems a producer that writes to a queue and a consumer that reads from a queue. This is desirable because it splits responsibility and allows for scalability. The code below is going to assume you have a rabbit MQ instance installed on your local machine. You can get rabbit MQ here:  https://www.rabbitmq.com/ Now the code is broken down into 3 parts, the main program, the producer, and the consumer. This is a basic example so its using old school threading rather than the new async/await .net prefers. But this is just to show how to use rabbit MQ in C# and to demonstrate a producer/consumer example. You will need to make sure your project has the rabbit MQ client nuget package installed...
Read more

C# Form Application in Kiosk Mode/Fullscreen

-
Sometimes you need to have a C# windows form application run in full screen mode.  Like you see on a kiosk at a mall or some stand alone machine.  It's fairly easy you just need to set some of the properties on the Form either in it's OnLoad method or directly in the designer. In the OnLoad method of the main Form set these values, or again set them directly in the designer. this.MaximizeBox = false; this.TopMost = true; this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None; this.WindowState = System.Windows.Forms.FormWindowState.Maximized;
Read more