Creating a Query

To create a new query, call the PdhOpenQuery function. The function returns a handle to the query to be used in other PDH function calls. You can create multiple queries to be used in your program.

After you create a query, call the PdhAddCounter function to add a counter to the query. Call PdhAddCounter for each counter to be added to the query. You can use one of the following methods to determine which counters to use.

• Hard-code the counter name in the call to PdhAddCounter. Use this method if you always monitor the same counter.
• Read the name from the registry or an initialization file. Use this method if the set of counters you monitor can change.
• Call the PdhBrowseCounters function to display the PDH browse dialog box. The dialog box allows the user to browse and select performance counters. For more information, see Browsing Performance Counters.

You should use the PdhRemoveCounter function to remove a counter from a query.