Hi,

I run some test to see what happen when a command button's picture property is assigned an ico file.

Initially, the icon file has 128x128, 96x96, 80x80, 72x72, 64x64,48x48, 32x32, 24x24 and 16x16 format and each size has 4 different color depth 4bits, 8bits, 24bits and 32 bits. (a total of 36 formats in the ico)
Under WinXp, VFP choose 32x32 RGB/A (32bits) format as the image for the button.
I delete that chosen format and run my text exe again, this time it chooses 32x32 16.8M (24bits) format and it follows. I mean each time a format is chosen as the image of the button, I remove that format from the ico file and run again the test exe to see what is the next prefered format...

I got a list of priority as below:
32x32 RGB/A (32 bits)
32x32 16.8M (24 bits)
32x32 256 Color (8 bits)
32x32 16 color (4 bits)
48x48 16 color
48x48 256 color
48x48 16.8M
64x64 16 color
64x64 256 color
64x64 16.8M
48x48 RGB/A
64x64 RGB/A
24x24 16 color
72x72 16 color
72x72 256 color
72x72 16.8M
72x72 RGB/A
24x24 256 color
24x24 16.8M
80x80 16 color
80x80 256 color
80x80 16.8M
24x24 RGB/A
80x80 RGB/A
16x16 16 color
16x16 256 color
16x16 16.8M
96x96 16 color
96x96 256 color
96x96 16.8M
16x16 RGB/A
96x96 RGB/A
128x128 16 color
128x128 256 color
128x128 16.8M
128x128 RGB/A

The way format is chosen is weird! It seems that neither size nor color depth is factor in determining a format to use, and I am lost...
Why is the format chosen in the above priority?
What are the factor that determines which format will be used?
Can anyone point me to an article or documentation on this issue?