问题
I'm currently able to obtain a file URI by opening the Lollipop file picker using the code below:
Intent intent = new Intent();
intent.setAction(Intent.ACTION_OPEN_DOCUMENT_TREE);
startActivity(intent);
The file picker opens either at the root of Internal Storage or the last directory that I opened. How can I make the file picker show the contents of a specific directory? For example, I might want the file picker to show the contents of the Download folder after launching like in the picture below.

回答1:
Use the Environment class which has methods like getExternalStorageDirectory()
or getDataDirectory()
https://developer.android.com/reference/android/os/Environment.html.
If the images are stored in a variable, grab them from that path:
private static final String fileName = Environment
.getExternalStorageDirectory().getAbsolutePath()
+ "/pathToFile.jpg";
来源:https://stackoverflow.com/questions/30115263/open-specific-directory-using-storage-access-framework