max demo 路径的走法 ，

file="g:\\subdir1\\subdir2\\myImage.jpg"
"g:\subdir1\subdir2\myImage.jpg"
filenameFromPath file -- returns: "myImage.jpg"
"myImage.jpg"
getFilenamePath file -- returns: "g:\subdir1\subdir2\"
"g:\subdir1\subdir2\"
getFilenameFile file -- returns: "myImage".
"myImage"
getFilenameType file -- returns: ".jpg"
".jpg"