Adds the specified counter to the query.

Syntax

PDH_STATUS PdhAddCounter(
  __in   PDH_HQUERY hQuery,
  __in   LPCTSTR szFullCounterPath,
  __in   DWORD_PTR dwUserData,
  __out  PDH_HCOUNTER *phCounter
);

Parameters

hQuery [in]

Handle to the query to which you want to add the counter. This handle is returned by the PdhOpenQuery function.

szFullCounterPath [in]

Null-terminated string that contains the counter path. For details on the format of a counter path, see Specifying a Counter Path. The maximum length of a counter path is PDH_MAX_COUNTER_PATH.

dwUserData [in]

User-defined value. This value becomes part of the counter information. To retrieve this value later, call the PdhGetCounterInfo function and access the dwUserData member of the PDH_COUNTER_INFO structure.

phCounter [out]

Handle to the counter that was added to the query. You may need to reference this handle in subsequent calls.

Return Value

Return ERROR_SUCCESS if the function succeeds.

If the function fails, the return value is a system error code or a PDH error code. The following are possible values.

Remarks

If the counter path contains a wildcard character, all counter names matching the wildcard character are added to the query.

If a counter instance is specified that does not yet exist, PdhAddCounter does not report an error condition. Instead, it returns ERROR_SUCCESS. The reason for this behavior is that it is not known whether a nonexistent counter instance has been specified or whether one will exist but has not yet been created.

To remove the counter from the query, use the PdhRemoveCounter function.

Examples

For an example, see Browsing Performance Counters or Reading Performance Data from a Log File.

Requirements

See Also

PdhAddEnglishCounter

PdhBrowseCounters

PdhMakeCounterPath

PdhOpenQuery

PdhRemoveCounter

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Build date: 11/12/2009