布局界面為兩個【輸入框】和兩個【按鈕】

程序代碼如下：

package com.twac.filetest;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.PRintStream;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;public class MainActivity extends Activity {	private Button btn_write;	private Button btn_read;	private EditText edt_write;	private EditText edt_read;	private final String FILE_NAME = "crazyit.bin";	@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);		btn_write = (Button) findViewById(R.id.btn_write);		btn_read = (Button) findViewById(R.id.btn_read);		edt_write = (EditText) findViewById(R.id.edt_write);		edt_read = (EditText) findViewById(R.id.edt_read);		btn_write.setOnClickListener(new OnClickListener() {			@Override			public void onClick(View arg0) {				// 將edt_write的內容寫入文件中				write(edt_write.getText().toString());				edt_write.setText("");			}		});		btn_read.setOnClickListener(new OnClickListener() {			@Override			public void onClick(View arg0) {				edt_read.setText(read());			}		});	}	private void write(String content) {		try {			// 以追加模式打開文件輸出流			FileOutputStream fos = openFileOutput(FILE_NAME, MODE_APPEND);			// 將FileOutputStream包裝成PrintStream			PrintStream ps = new PrintStream(fos);			// 輸出文件內容			ps.println(content);			// 關閉文件輸出流			ps.close();		} catch (FileNotFoundException e) {			e.printStackTrace();		}	}	private String read() {		try {			// 打開文件輸入流			FileInputStream fis = openFileInput(FILE_NAME);			byte[] buff = new byte[1024];			int hasRead = 0;			StringBuffer sb = new StringBuffer("");			// 讀取文件內容			while ((hasRead = fis.read(buff)) > 0) {				sb.append(new String(buff, 0, hasRead));			}			// 關閉文件輸入流			fis.close();			return sb.toString();		} catch (FileNotFoundException e) {			e.printStackTrace();		} catch (IOException e) {			e.printStackTrace();		}		return null;	}}