if(name.trim().equals("")){    Toast.makeText(this, "請您輸入用戶名！", Toast.LENGTH_SHORT).show();    return;   }   if(pswd.trim().equals("")){    Toast.makeText(this, "請您輸入密碼！", Toast.LENGTH_SHORT).show();    return;   }

//通過boolean CheckBoxLogin = checkbox.isChecked();   //按鈕被選中，下次進入時會顯示賬號和密碼          if (CheckBoxLogin)   {     Editor editor = sp.edit();     editor.putString("uname", name);     editor.putString("upswd", pswd);     editor.putBoolean("auto", true);     editor.commit();   }   //按鈕被選中，清空賬號和密碼，下次進入時會顯示賬號和密碼       else      {     Editor editor = sp.edit();    editor.putString("uname", null);    editor.putString("upswd", null);    editor.putBoolean("auto", false);    editor.commit();    }

//先定義SharedPreferences sp = null; sp = this.getSharedPreferences("userinfo", Context.MODE_PRIVATE);//對uname 和 upswd 的操作 if (sp.getBoolean("checkboxBoolean", false))   {    uname.setText(sp.getString("uname", null));    upswd.setText(sp.getString("upswd", null));     checkboxButton.setChecked(true);   }

//Intent跳轉Intent intent = new Intent(Welcome.this,Content.class);startActivity(intent);finish();

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"  android:background="#ADD8E6"> <RelativeLayout  android:id="@+id/login_div"  android:layout_width="fill_parent"  android:layout_height="221dp"  android:layout_margin="15dip"  android:background="@drawable/btn_bg"  android:padding="15dip" >  <TextView   android:id="@+id/login_user_input"   android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:layout_alignParentTop="true"   android:layout_margin="5dp"   android:text="@string/user"   android:textSize="16dp"   android:typeface="sans" />  <EditText   android:id="@+id/user_input"   android:layout_width="fill_parent"   android:layout_height="wrap_content"   android:layout_below="@id/login_user_input"   android:background="@android:drawable/editbox_background"   android:inputType="text"   android:singleLine="true" />  <TextView   android:id="@+id/login_pass_input"   android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:layout_below="@id/user_input"   android:layout_margin="5dp"   android:text="@string/pass"   android:textSize="16dp"   android:typeface="sans" />  <EditText   android:id="@+id/pass_input"   android:layout_width="fill_parent"   android:layout_height="wrap_content"   android:layout_below="@id/login_pass_input"   android:background="@android:drawable/editbox_background"   android:inputType="textPassword"   android:singleLine="true" />  <CheckBox   android:id="@+id/checkBoxLogin"   android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:layout_alignLeft="@+id/pass_input"   android:layout_alignParentBottom="true"   android:text="@string/no_user" />  <Button   android:id="@+id/new_user"   android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:layout_alignParentBottom="true"   android:layout_alignRight="@+id/pass_input"   android:layout_marginRight="28dp"   android:onClick="To_Title"   android:text="@string/new_user" /> </RelativeLayout>  <LinearLayout   android:layout_width="match_parent"   android:layout_height="match_parent"   android:orientation="vertical" >   <TextView    android:layout_width="402dp"    android:layout_height="51dp"    android:layout_marginLeft="50dp"    android:background="@drawable/gxs_ziti" />   <Button    android:layout_width="120dp"    android:layout_height="120dp"    android:onClick="To_fruist"    android:background="@drawable/gxs2"     android:layout_marginLeft="80dp"    />  </LinearLayout></LinearLayout>

package com.gxs.login;import com.example.login.R;import com.gxs.listview.*;import android.os.Bundle;import android.preference.Preference;import android.app.Activity;import android.app.SearchManager.OnCancelListener;import android.content.Context;import android.content.Intent;import android.content.SharedPreferences;import android.content.SharedPreferences.Editor;import android.util.Log;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.CheckBox;import android.widget.EditText;import android.widget.Toast;public class Welcome extends Activity implements OnClickListener{ private EditText uname = null; private EditText upswd = null; private CheckBox checkboxButton = null; private Button login = null; SharedPreferences sp = null;  @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.layout_main);  sp = this.getSharedPreferences("userinfo", Context.MODE_PRIVATE);  init(); } public void init() {  uname = (EditText) findViewById(R.id.user_input);  upswd = (EditText) findViewById(R.id.pass_input);  checkboxButton = (CheckBox) findViewById(R.id.checkBoxLogin);  login = (Button) findViewById(R.id.new_user);  if (sp.getBoolean("checkboxBoolean", false))   {    uname.setText(sp.getString("uname", null));    upswd.setText(sp.getString("upswd", null));     checkboxButton.setChecked(true);   }  login.setOnClickListener(this); } @Override public void onClick(View v) {  if (v == login){   String name = uname.getText().toString();   String pswd = upswd.getText().toString();   if(name.trim().equals("")){    Toast.makeText(this,     "請您輸入用戶名！", Toast.LENGTH_SHORT).show();    return;   }   if(pswd.trim().equals("")){    Toast.makeText(this,     "請您輸入密碼！", Toast.LENGTH_SHORT).show();    return;   }   boolean CheckBoxLogin = checkboxButton.isChecked();   if (CheckBoxLogin)   {     Editor editor = sp.edit();     editor.putString("uname", name);     editor.putString("upswd", pswd);     editor.putBoolean("checkboxBoolean", true);     editor.commit();   }   else   {     Editor editor = sp.edit();    editor.putString("uname", null);    editor.putString("upswd", null);    editor.putBoolean("checkboxBoolean", false);    editor.commit();    }   //Intent跳轉   Intent intent=new Intent(Welcome.this,Content.class);   startActivity(intent);   finish();  } }}

package com.gxs.listview;import java.util.List;import com.example.login.R;import com.gxs.*;import android.app.Activity;import android.os.Bundle;import android.widget.ArrayAdapter;import android.widget.ListView;public class Content extends Activity{ private ListView listview_fruits;  @Override protected void onCreate(Bundle savedInstanceState) {  // TODO Auto-generated method stub  super.onCreate(savedInstanceState);  setContentView(R.layout.content); }}

<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:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".Welcome"  > <TextView  android:id="@+id/textView1"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:text="內容"  android:textAppearance="?android:attr/textAppearanceLarge" /></LinearLayout>