IO -- (4) SDCARD

IO: 列出SDCARD裡的夾子與檔案 ＆ 讀取SDCARD裡某檔案的內容 

public class IO_ListSDCardFilesActivity extends Activity {
    /** Called when the activity is first created. */

private final String SD_PATH = Environment.getExternalStorageDirectory().getAbsolutePath();
private final String FILE_PATH = "/fileio";
private final String FILE_NAME = "test02.txt";
private final String ENCODING = "UTF-8";

FileInputStream fis = null; // 這裡要設定，否則無法用

TextView tv;
ListView lv;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
     
        tv = (TextView) findViewById(R.id.textView);
     
        //列出Sdcard 裡的夾子和檔案，放上LISTVIEW
        try {
        File sdcardPATH = Environment.getExternalStorageDirectory();// 找SD的入徑
        String [] fileNamesArrayStr = sdcardPATH.list(); // 用list(),將SD裡的資料夾和檔案以字串的方式收集在array
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, fileNamesArrayStr);// 以 listView 顯示在螢幕上
        lv = (ListView) findViewById(R.id.listView1);
        lv.setAdapter(adapter);
        } catch (Exception e) {
        e.printStackTrace();
        }
 
     
        readFile(); //讀出指定的檔到TEXTVIEW上
     
    }// end of onCreate
 
 
 
    public void readFile () {
   
    String result = "";
    try {
   
    File mFilePath = new File (SD_PATH + FILE_PATH);
    String mFileName = mFilePath + "/" + FILE_NAME;
    File fileText = new File (mFileName);
   
    fis = new FileInputStream(fileText);
    int length = fis.available();
    byte [] buffer = new byte [length];
    fis.read(buffer);
    result = EncodingUtils.getString(buffer, ENCODING);
    fis.close();
    tv.setText(result);
   
    } catch (Exception e) {
    e.printStackTrace();
    }
    }// end of readFile();
}