SharedPreferences---保存数据、在界面跳转时传递数值
注册界面：public class MainActivity extends Activity {EditText username, password;Button registration;SharedPreferences sp;Editor editor;String name;String pass;Intent intent; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initControl(); //得到SharedPreferences，会生成user.xml sp = this.getSharedPreferences("user", 0); editor = sp.edit(); registration.setOnClickListener(new ButtonListener()); } /** * 根据ID得到控件 */ private void initControl(){ username = (EditText) findViewById(R.id.username); password = (EditText) findViewById(R.id.password); registration = (Button) findViewById(R.id.registration); } /** * 按钮的监听类 * @author symbolDelia * */ private class ButtonListener implements OnClickListener{
@Overridepublic void onClick(View v) {name = username.getText().toString();pass = password.getText().toString();//下面三行是将数据写入user.xml中editor.putString("username", name);editor.putString("password", pass);editor.commit();Toast.makeText(MainActivity.this, "注册成功", Toast.LENGTH_SHORT).show();//写入xml之后，将EditText设为空username.setText("");password.setText("");//跳转页面intent = new Intent();intent.setClass(MainActivity.this, Land.class);startActivity(intent);} }
@Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; }}
XML：
<RelativeLayout 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" >
<TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/username" tools:context=".MainActivity" />
<EditText android:id="@+id/username" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_marginLeft="15dp" android:layout_toRightOf="@+id/textView1" android:ems="10" android:hint="@string/username" android:inputType="text" >
<requestFocus /> </EditText>
<TextView android:id="@+id/textView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignRight="@+id/textView1" android:layout_below="@+id/username" android:layout_marginTop="24dp" android:text="@string/password" />
<EditText android:id="@+id/password" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignBaseline="@+id/textView2" android:layout_alignBottom="@+id/textView2" android:layout_alignLeft="@+id/username" android:ems="10" android:inputType="textPassword" android:hint="@string/password" />
<Button android:id="@+id/registration" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/textView2" android:layout_below="@+id/password" android:layout_marginLeft="24dp" android:layout_marginTop="40dp" android:text="@string/registration" />
</RelativeLayout>


登陆页面：
public class Land extends Activity {EditText username, password;Button land;String editname, editpass;String name, pass;SharedPreferences shared;Intent intent;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.land);initControl();//得到SharedPreferences，这里是得到之前的user.xmlshared = this.getSharedPreferences("user", 0);//得到user.xml中username和password键的对应值name = shared.getString("username", null);pass = shared.getString("password", null);//监听land.setOnClickListener(new LandListener());} /** * 根据ID得到控件 */private void initControl(){username = (EditText) findViewById(R.id.landusername);password = (EditText) findViewById(R.id.landpassword);land = (Button) findViewById(R.id.land);}/** * 按钮的监听类 * @author symbolDelia * */private class LandListener implements OnClickListener{
@Overridepublic void onClick(View v) {//得到EditText里的内容editname = username.getText().toString();editpass = password.getText().toString();//比较EditText里的值是否与SharedPreferences中得到的值一样if(editname.equals(name) && editpass.equals(pass)){Toast.makeText(Land.this, "登陆成功", Toast.LENGTH_LONG).show();intent = new Intent();intent.setClass(Land.this, GetUserInformation.class);startActivity(intent);}else{Toast.makeText(Land.this, "用户名或密码不不正确", Toast.LENGTH_LONG).show();}}}}
XML：
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" >
<TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_marginRight="23dp" android:layout_marginTop="157dp" android:text="@string/username" />
<EditText android:id="@+id/landusername" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignBaseline="@+id/textView1" android:layout_alignBottom="@+id/textView1" android:layout_alignParentRight="true" android:ems="10" android:inputType="text" android:hint="@string/username" >
<requestFocus /> </EditText>
<TextView android:id="@+id/textView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_centerVertical="true" android:text="@string/password" />
<EditText android:id="@+id/landpassword" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignBaseline="@+id/textView2" android:layout_alignBottom="@+id/textView2" android:layout_alignLeft="@+id/landusername" android:ems="10" android:inputType="textPassword" android:hint="@string/password"/>
<Button android:id="@+id/land" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/landpassword" android:layout_marginTop="70dp" android:layout_toRightOf="@+id/textView2" android:text="@string/land" />
</RelativeLayout>


获取用户信息页面：
public class GetUserInformation extends ListActivity {SharedPreferences shared;String username, password;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);//得到SharedPreferences，这里是得到之前的user.xmlshared = this.getSharedPreferences("user", 0);//得到user.xml中username和password键的对应值username = shared.getString("username", null);password = shared.getString("password", null);//设置适配器SimpleAdapter adapter = new SimpleAdapter(this, getData(), R.layout.getuserinformation, new String[]{"name", "pass"}, new int[]{R.id.getusername, R.id.getpassword});setListAdapter(adapter);}//得到数据private List<Map<String, String>> getData(){List<Map<String, String>> datas = new ArrayList<Map<String, String>>();Map<String, String> data = new HashMap<String, String>();data.put("name", username);data.put("pass", password);datas.add(data);return datas;}}
XML：
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" >
<TextView android:id="@+id/getusername" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentTop="true" android:layout_marginLeft="25dp" android:layout_marginTop="20dp" android:text="@string/username" />
<TextView android:id="@+id/getpassword" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignBaseline="@+id/getusername" android:layout_alignBottom="@+id/getusername" android:layout_alignParentRight="true" android:layout_marginRight="50dp" android:text="@string/password" />
</RelativeLayout>

string.xml:
<resources>
<string name="app_name">MySharedPreferences</string> <string name="hello_world">Hello world!</string> <string name="menu_settings">Settings</string> <string name="title_activity_main">MainActivity</string> <string name="username">用户名：</string> <string name="password">密 码：</string> <string name="registration">注册</string> <string name="getuserinformation">获取用户信息</string> <string name="land">登陆</string> <string name="registrationpage">注册界面</string> <string name="getuserinformationpage">获取用户信息界面</string> <string name="landpage">登陆界面</string>
</resources>