package com.sdmadik;

import java.io.*;

import android.app.Activity;

import android.os.Bundle;

import android.view.*;

import android.view.View.OnClickListener;

import android.widget.*;

public class FileUse extends Activity {

    // GUI controls

    EditText txtData;

    Button btnWriteSDFile;

    Button btnReadSDFile;

    Button btnClearScreen;

    Button btnClose;

    @Override

    public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);

    // bind GUI elements with local controls

    txtData = (EditText) findViewById(R.id.txtData);

    txtData.setHint("Enter some lines of data here...");

        //setHint寫法與setText相似。

    btnWriteSDFile = (Button) findViewById(R.id.btnWriteSDFile);

    btnWriteSDFile.setOnClickListener(new OnClickListener() {

    public void onClick(View v) {

        // 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(txtData.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.btnReadSDFile);

        btnReadSDFile.setOnClickListener(new 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";

            }

            txtData.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();

        }

        }// onClick

        }); // btnReadSDFile

        btnClearScreen = (Button) findViewById(R.id.btnClearScreen);

        btnClearScreen.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {

                // clear text box

                txtData.setText("");

            }

        }); // btnClearScreen

        btnClose = (Button) findViewById(R.id.btnClose);

        btnClose.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {

                // clear text box

                finish();

            }

        }); // btnClose

    }// onCreate

}// AndSDcard

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

android:id="@+id/widget28"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:background="#ff0000ff"

android:orientation="vertical"

xmlns:android="http://schemas.android.com/apk/res/android"

>

<EditText

android:id="@+id/txtData"

android:layout_width="fill_parent"

android:layout_height="180px"

android:textSize="18sp"  />

<Button

android:id="@+id/btnWriteSDFile"

android:layout_width="143px"

android:layout_height="44px"

android:text="1. Write SD File"  />

<Button

android:id="@+id/btnClearScreen"

android:layout_width="141px"

android:layout_height="42px"

android:text="2. Clear Screen"  />

<Button

android:id="@+id/btnReadSDFile"

android:layout_width="140px"

android:layout_height="42px"

android:text="3. Read SD File"  />

<Button

android:id="@+id/btnClose"

android:layout_width="141px"

android:layout_height="43px"

android:text="4. Close" />

</LinearLayout>