You’ve previously inquired about the error code 0x000005B5, which translates to ERROR_INVALID_MONITOR_HANDLE. Here’s a recap of how to fix this error:

Understanding ERROR_INVALID_MONITOR_HANDLE:

This error occurs in Windows programs when you attempt to use an invalid monitor handle with a monitor-related function in the Windows API.

Monitor Handles in Windows:

• Monitor handles are used to interact with display devices and retrieve information about them.
• These handles are obtained using functions like EnumDisplayMonitors or CreateWindowEx with specific flags.

Causes of ERROR_INVALID_MONITOR_HANDLE:

• Incorrect Handle Usage: The most common cause is using an invalid monitor handle in your code. This can happen due to:

  • Typos or errors in the handle name.
  • Using a handle that has already been closed.
  • Using a handle that refers to a monitor that has become disconnected or unavailable.

• Incorrect Handle Management: Not properly closing monitor handles after you’re done using them can lead to handle exhaustion and attempts to use invalid handles later.

• Code Errors: Mistakes in how you’re obtaining, managing, or using monitor handles within your program can lead to this error.

Troubleshooting Steps:

1. Verify Handle Name: Double-check the code where you’re using the monitor handle and ensure the name matches exactly with the variable where you stored the handle after creating it using EnumDisplayMonitors or CreateWindowEx.

2. Debug Handle Usage: Use debugging tools to inspect the value of the monitor handle before using it in monitor-related functions. This can help identify if the handle is indeed invalid or has become null due to improper closing.

3. Review Handle Management: Ensure you’re properly closing monitor handles using the CloseHandle function after you’re finished using them. Leaking handles can exhaust system resources and lead to invalid handle errors.

4. Check Monitor Availability: If you’re working with multiple monitors, confirm that the monitor you’re referencing is still connected and available to the system. Disconnected monitors will result in invalid handles.

5. Consult Windows API Documentation: Refer to the documentation for the Windows API functions you’re using for monitor interaction, such as EnumDisplaySettings or GetMonitorInfoEx. The documentation typically specifies the expected handle type and usage guidelines.

Additional Tips:

• Use meaningful variable names to identify monitor handles. This improves code readability and reduces the risk of typos.
• Consider using a try-catch block (if your programming language supports it) to handle potential exceptions related to invalid handles. This can help gracefully recover from handle-related errors.
• If working with multiple handles, explore using handle management libraries or techniques to keep track of open handles and ensure proper closing to avoid resource leaks.

By following these steps and understanding the reasons behind the ERROR_INVALID_MONITOR_HANDLE error, you can identify the issue in your code related to typos, handle usage, or handle management. You can then fix typos, use the correct handle, ensure you’re obtaining and closing monitor handles appropriately within your program, and verify that the monitor you’re referencing is available.