Get the logical and real extents of the specified string as if it were drawn with this font.
Bytes specifies the number of bytes to take from the string or -1 for the complete NULL-terminated string.
从字符串中指定要画的字节数，或者为－1的时候画完字符串从NULL到结束。
The logical rectangle describes the typographic extents and should be used to layout text. The ink rectangle describes the smallest rectangle containing all pixels that are touched when drawing the string. If you only need one of the rectangles, pass NULL for the other one.
这个逻辑的矩形描绘这个印刷的宽度并且被用在布局文本。当画字符串时，黑色的矩形描绘最小的矩形被创建，包含了所有象素。如果你只需要这些矩形的一个，传递NULL为另外一个。
The ink rectangle is guaranteed to be a valid rectangle with positive width and height, while the logical rectangle may have negative width indicating right-to-left layout.
这个黑色矩形被确保是一个有效的矩形用正数宽度和正数高度，然而逻辑矩形有负数宽度表明从右到左布局。
The rectangle offsets are reported relative to the baseline and refer to the text being drawn using DSTF_LEFT.
矩形以基线为准的偏移被报告而且涉及到用DSTF_LEFT画文本。
