Android程序第5次作业

package com.example.assignment;

import android.app.AlertDialog;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

import android.os.Bundle;
import android.app.Activity;
import android.content.DialogInterface;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button buttonSave = (Button)findViewById(R.id.buttonSave);
        buttonSave.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				String filename = "data.txt";
				String content = "helloworld";
				FileOutputStream fos = null;
				try {
					fos = openFileOutput(filename, MODE_PRIVATE);
					fos.write(content.getBytes());
				}
				catch(Exception e) {
					e.printStackTrace();
				}
				finally {
					try {
						if (fos != null) {
							fos.close();
						}
					}
					catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
		});
        Button buttonRead = (Button)findViewById(R.id.buttonRead);
        buttonRead.setOnClickListener(new View.OnClickListener() {
        	
        	@Override
        	public void onClick(View v) {
        		String content = "";
        		FileInputStream fis = null;
        		try {
        			fis = openFileInput("data.txt");
        			byte[] buffer = new byte[fis.available()];
        			fis.read(buffer);
        			content = new String(buffer);
        		}
        		catch (Exception e) {
        			e.printStackTrace();
        		}
        		finally {
        			try {
        				if (fis != null) {
        					fis.close();
        				}
        			}
        			catch (IOException e) {
    					e.printStackTrace();
    				}
        		}
        		AlertDialog dialog;
        		AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this)
        			.setTitle("data content")
        			.setIcon(R.drawable.ic_launcher)
        			.setMessage(content)
        			.setPositiveButton("存储数据", new DialogInterface.OnClickListener() {
						
						@Override
						public void onClick(DialogInterface dialog, int which) {
							dialog.dismiss();
						}
					});
        		dialog = builder.create();
        		dialog.show();
        	}
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/buttonSave"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="保存数据" />
    
    <Button
        android:id="@+id/buttonRead"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="读取数据" />

</LinearLayout>

package com.example.assignment;

import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.content.DialogInterface;
import android.content.SharedPreferences;

public class LoginActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_login);
		
		SharedPreferences sharedPreferences = getSharedPreferences("data", MODE_PRIVATE);
		String username = sharedPreferences.getString("username", "");
		String password = sharedPreferences.getString("password", "");
		EditText editTextUserName = (EditText)findViewById(R.id.editTextUserName);
		editTextUserName.setText(username);
		EditText editTextPassword = (EditText)findViewById(R.id.editTextPassword);
		editTextPassword.setText(password);
		
		Button buttonSave = (Button)findViewById(R.id.buttonSave);
		buttonSave.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View view) {
				SharedPreferences sharedPreferences = getSharedPreferences("data", MODE_PRIVATE);
				SharedPreferences.Editor editor = sharedPreferences.edit();
				EditText editTextUserName = (EditText)findViewById(R.id.editTextUserName);
				editor.putString("username", editTextUserName.getText().toString());
				EditText editTextPassword = (EditText)findViewById(R.id.editTextPassword);
				editor.putString("password", editTextPassword.getText().toString());
				editor.commit();
			}
		});
		Button buttonLogin = (Button)findViewById(R.id.buttonLogin);
		buttonLogin.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				EditText editTextUserName = (EditText)findViewById(R.id.editTextUserName);
				String username = editTextUserName.getText().toString();
				EditText editTextPassword = (EditText)findViewById(R.id.editTextPassword);
				String password = editTextPassword.getText().toString();
				AlertDialog dialog;
        		AlertDialog.Builder builder = new AlertDialog.Builder(LoginActivity.this)
        			.setTitle("data content")
        			.setIcon(R.drawable.ic_launcher)
        			.setMessage("data" + username + "\n" + password + "\n")
        			.setPositiveButton("确定", new DialogInterface.OnClickListener() {
						
						@Override
						public void onClick(DialogInterface dialog, int which) {
							dialog.dismiss();
						}
					});
        		dialog = builder.create();
        		dialog.show();
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.login, menu);
		return true;
	}

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".LoginActivity" >

    <LinearLayout
	    android:layout_width="match_parent"
	    android:layout_height="wrap_content">
	    <TextView
	        android:layout_width="52px"
	        android:layout_height="wrap_content"
	        android:text="账号" />
	    <EditText 
	        android:id="@+id/editTextUserName"
	        android:layout_width="wrap_content"
	        android:layout_height="wrap_content"
	        android:hint="请输入用户名" />
    </LinearLayout>
    
	<LinearLayout
	    android:layout_width="match_parent"
	    android:layout_height="wrap_content">
	    <TextView
	        android:layout_width="52px"
	        android:layout_height="wrap_content"
	        android:text="密码" />
	    <EditText 
	        android:id="@+id/editTextPassword"
	        android:layout_width="wrap_content"
	        android:layout_height="wrap_content"
	        android:hint="请输入密码" />
    </LinearLayout>
    
	<Button
	    android:id="@+id/buttonSave"
	    android:layout_width="match_parent"
	    android:layout_height="wrap_content"
	    android:layout_gravity="center"
	    android:text="保存" />
	<Button
	    android:id="@+id/buttonLogin"
	    android:layout_width="match_parent"
	    android:layout_height="wrap_content"
	    android:layout_gravity="center"
	    android:text="登录" />

</LinearLayout>