Android判斷sd卡是否可寫

private static boolean checkFsWritable() {
// Create a temporary file to see whether a volume is really writeable.
// It's important not to put it in the root directory which may have a
// limit on the number of files.
String directoryName =
Environment.getExternalStorageDirectory().toString() + "/DCIM";//External.getExternalStorageDirectory() 返回存儲卡位置的名稱
File directory = new File(directoryName);
if (!directory.isDirectory()) {
if (!directory.mkdirs()) {
return false;
}
}
File f = new File(directoryName, ".probe");
try {
// Remove stale file if any
if (f.exists()) {
f.delete();
}
if (!f.createNewFile()) {
return false;
}
f.delete();
return true;
} catch (IOException ex) {
return false;
}
}