GetTextExtent vs. GetTextExtentPoint32: Understanding the Differences in Text Size Measurement

GetTextExtent and GetTextExtentPoint32 are both Windows API functions used to retrieve the width and height of a text string, but they differ in their parameters and return values.

GetTextExtent

• Parameters: HDC, LPCTSTR, int
  • HDC: Device context handle.
  • LPCTSTR: Pointer to the text string to measure.
  • int: Length of the string.
• Return Value: A SIZE structure containing:
  • cx: Text string width.
  • cy: Text string height.

GetTextExtentPoint32

• Parameters: HDC, LPCTSTR, int
  • HDC: Device context handle.
  • LPCTSTR: Pointer to the text string to measure.
  • int: Length of the string.
• Return Value:
  • BOOL: Indicates success or failure of the function.
  • POINT: (If successful) A POINT structure containing:
    • x: Text string width.
    • y: Text string height.

Key Differences

GetTextExtent returns a SIZE structure containing the text dimensions, while GetTextExtentPoint32 returns a BOOL value (indicating success) and a POINT structure with the dimensions. If you only need the text width and height, use GetTextExtent. If you also require the text coordinates, use GetTextExtentPoint32.