1、写入数据APP

public class MainActivity extends Activity {

	private SharedPreferences putPreferences;
	private Editor putEditor;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		// 将服务器信息写入serverInfo.xml
		findViewById(R.id.buttonPut).setOnClickListener( new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				putPreferences = getSharedPreferences("serverInfo", Context.MODE_WORLD_READABLE);
				putEditor = putPreferences.edit();
				putEditor.putString("serverIP", "192.168.1.102");
				putEditor.putString("password", "123456");
				putEditor.commit();
				Toast.makeText(MainActivity.this,"服务器信息成功写入serverInfo.xml", Toast.LENGTH_LONG).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;
	}

}

2、获取数据APP

public class MainActivity extends Activity {

	private SharedPreferences getPreferences;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		//从serverInfo.xml获取服务器信息
		findViewById(R.id.buttonGet).setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				try {
					Context context=createPackageContext("com.example.putprefapp", Context.CONTEXT_IGNORE_SECURITY);
					getPreferences=context.getSharedPreferences("serverInfo", MODE_WORLD_READABLE);
					String serverIP=getPreferences.getString("serverIP","");
					String serverPwd=getPreferences.getString("password", "");
					Toast.makeText(MainActivity.this, "服务器信息如下：IP地址：" +serverIP+"; 密码："+serverPwd, Toast.LENGTH_LONG).show();
				} catch (NameNotFoundException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		});
		
	}

	@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;
	}

}

3、关于android:sharedUserId

上面的两个工程中并没有对android:sharedUserId属性进行设置。这个属性是在查资料时看到的：意思是说，在manifest.xml里面将两个应用程序的android:sharedUserId属性设为相同的就可以对SharedPreferences文件进行写。（此处并没有验证）