如何从SD卡中读取数据并在android中显示另一个活动的微调器

Question

我正确地将文件保存在SD卡中，但是不检索SD卡文本文件的数据并显示在另一个活动的微调器上。当我点击读取按钮时，数据显示在另一个活动的微调器上     当我点击微调器上的阅读按钮txt文件项目显示

mainactivity.java

btnWriteSDFile = (Button) findViewById(R.id.Write);
btnWriteSDFile.setOnClickListener(new View.OnClickListener() {

    public void onClick(View v) {
        Jour = display.getText().toString();
        // write on SD card file data in the text box
        try {
            File myFile = new File("/sdcard/mysdfile.txt");
            myFile.createNewFile();
            FileOutputStream fOut = new FileOutputStream(myFile);
            OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut);
            myOutWriter.append(display.getText());
            myOutWriter.close();
            fOut.close();
            Toast.makeText(getBaseContext(), "Done writing SD 'mysdfile.txt'", Toast.LENGTH_SHORT).show();
        } catch (Exception e) {
            Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
        }

    } // onClick
}); // btnWriteSDFile

btnReadSDFile = (Button) findViewById(R.id.Read);
btnReadSDFile.setOnClickListener(new View.OnClickListener() {

    public void onClick(View v) {
        // write on SD card file data in the text box
        try {
            File myFile = new File("/sdcard/mysdfile.txt");
            FileInputStream fIn = new FileInputStream(myFile);
            BufferedReader myReader = new BufferedReader( new InputStreamReader(fIn));
            String aDataRow = "";
            String aBuffer = "";
            while ((aDataRow = myReader.readLine()) != null) {
                aBuffer += aDataRow + "\n";
            }
            display.setText(aBuffer);
            myReader.close();
            Toast.makeText(getBaseContext(), "Done reading SD 'mysdfile.txt'", Toast.LENGTH_SHORT).show();
        } catch (Exception e) {
            Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }       
}); 

list.java

Spinner sp1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.list);
    sp1 = (Spinner) findViewById(R.id.spinner1);
    getFilesnames();        
}
private void getFilesnames() {
    String[] filenames=getApplicationContext().fileList();
    List<String> list=new ArrayList<String>();
    for(int i = 0; i < filenames.length; i++) {
        list.add(filenames[i]);
    }
    ArrayAdapter<String> filenameAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,list);
    sp1.setAdapter(filenameAdapter);
}