<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"  package="com.itheima27.sutdentmanager"  android:versionCode="1"  android:versionName="1.0" >   <uses-sdk   android:minSdkVersion="8"   android:targetSdkVersion="17" />  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>   <application   android:allowBackup="true"   android:icon="@drawable/ic_launcher"   android:label="@string/app_name"   android:theme="@style/AppTheme" >   <activity    android:name="com.itheima27.sutdentmanager.MainActivity"    android:label="@string/app_name"    android:theme="@android:style/Theme.NoTitleBar" >    <intent-filter>     <action android:name="android.intent.action.MAIN" />      <category android:name="android.intent.category.LAUNCHER" />    </intent-filter>   </activity>  </application>  </manifest> 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:background="@android:color/white"  android:orientation="vertical" >   <TextView   android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:layout_gravity="center_horizontal"   android:layout_marginTop="5dip"   android:text="學生管理系統"   android:textColor="#99CCFF"   android:textSize="23sp" />   <RelativeLayout   android:layout_width="fill_parent"   android:layout_height="wrap_content"   android:layout_marginTop="5dip"   android:padding="5dip" >    <TextView    android:id="@+id/tv_name"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:paddingLeft="15dip"    android:paddingRight="15dip"    android:text="姓名"    android:textSize="18sp" />    <TextView    android:id="@+id/tv_sex"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_marginLeft="5dip"    android:layout_toRightOf="@id/tv_name"    android:paddingLeft="15dip"    android:paddingRight="15dip"    android:text="性別"    android:textSize="18sp" />    <TextView    android:id="@+id/tv_age"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_marginLeft="5dip"    android:layout_toRightOf="@id/tv_sex"    android:paddingLeft="15dip"    android:paddingRight="15dip"    android:text="年齡"    android:textSize="18sp" />    <EditText    android:id="@+id/et_name"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_alignLeft="@id/tv_name"    android:layout_alignRight="@id/tv_name"    android:layout_below="@id/tv_name"    android:singleLine="true" />    <EditText    android:id="@+id/et_sex"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_alignLeft="@id/tv_sex"    android:layout_alignRight="@id/tv_sex"    android:layout_below="@id/tv_sex"    android:singleLine="true" />    <EditText    android:id="@+id/et_age"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_alignLeft="@id/tv_age"    android:layout_alignRight="@id/tv_age"    android:layout_below="@id/tv_age"    android:inputType="number"    android:singleLine="true" />    <Button    android:id="@+id/btn_add_student"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_alignBaseline="@id/et_age"    android:layout_toRightOf="@id/et_age"    android:text="添加學生"    android:textSize="20sp" />  </RelativeLayout>   <ScrollView   android:layout_width="fill_parent"   android:layout_height="wrap_content"   android:layout_weight="1" >    <LinearLayout    android:id="@+id/ll_student_list"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:layout_margin="1dip"    android:orientation="vertical"    android:padding="5dip" >   </LinearLayout>  </ScrollView>   <LinearLayout   android:layout_width="fill_parent"   android:layout_height="wrap_content"   android:layout_marginTop="5dip"   android:orientation="horizontal" >    <Button    android:id="@+id/btn_save"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_weight="1"    android:text="保存數據"    android:textSize="20sp" />    <Button    android:id="@+id/btn_restore"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_weight="1"    android:text="恢復數據"    android:textSize="20sp" />  </LinearLayout>  </LinearLayout> 

package com.itheima27.sutdentmanager.entities;  public class Student {   private String name;  private String sex;  private Integer age;  public Student(String name, String sex, Integer age) {   super();   this.name = name;   this.sex = sex;   this.age = age;  }  public Student() {   super();   // TODO Auto-generated constructor stub  }  public String getName() {   return name;  }  public void setName(String name) {   this.name = name;  }  public String getSex() {   return sex;  }  public void setSex(String sex) {   this.sex = sex;  }  public Integer getAge() {   return age;  }  public void setAge(Integer age) {   this.age = age;  }  @Override  public String toString() {   return "Student [name=" + name + ", sex=" + sex + ", age=" + age + "]";  } } 

package com.itheima27.sutdentmanager;  import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; import java.util.List;  import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import org.xmlpull.v1.XmlSerializer;  import com.itheima27.sutdentmanager.entities.Student;  import android.os.Bundle; import android.os.Environment; import android.app.Activity; import android.graphics.Color; import android.text.TextUtils; import android.util.Xml; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.EditText; import android.widget.LinearLayout; import android.widget.TextView; import android.widget.Toast;  public class MainActivity extends Activity implements OnClickListener {   private EditText etName;  private EditText etSex;  private EditText etAge;  private LinearLayout llStudentList;  private List<Student> studentList;  private String filePath;   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);      init();  }   private void init() {   etName = (EditText) findViewById(R.id.et_name);   etSex = (EditText) findViewById(R.id.et_sex);   etAge = (EditText) findViewById(R.id.et_age);      llStudentList = (LinearLayout) findViewById(R.id.ll_student_list);    findViewById(R.id.btn_save).setOnClickListener(this);   findViewById(R.id.btn_restore).setOnClickListener(this);   findViewById(R.id.btn_add_student).setOnClickListener(this);      studentList = new ArrayList<Student>();   filePath = Environment.getExternalStorageDirectory().getPath() + "/student.xml";  }   @Override  public void onClick(View v) {   switch (v.getId()) {   case R.id.btn_save:    if(studentList.size() > 0) {     if(saveStudent2Local()) {      Toast.makeText(this, "保存成功", 0).show();     } else {      Toast.makeText(this, "保存失敗", 0).show();     }    } else {     Toast.makeText(this, "當前沒有數據", 0).show();    }    break;   case R.id.btn_restore:    if(restoreStudentFromLocal()) {     Toast.makeText(this, "恢復成功", 0).show();    } else {     Toast.makeText(this, "恢復失敗", 0).show();    }    break;   case R.id.btn_add_student:    addStudent();    break;   default:    break;   }  }    private boolean restoreStudentFromLocal() {   try {    XmlPullParser parser = Xml.newPullParser();    parser.setInput(new FileInputStream(filePath), "utf-8");        int eventType = parser.getEventType();        studentList.clear();        Student student = null;    String nodeName = null;    while(eventType != XmlPullParser.END_DOCUMENT) {     nodeName = parser.getName();     switch (eventType) {     case XmlPullParser.START_TAG:      if("student".equals(nodeName)) {       student = new Student();      } else if("name".equals(nodeName)) {       student.setName(parser.nextText());      } else if("sex".equals(nodeName)) {       student.setSex(parser.nextText());      } else if("age".equals(nodeName)) {       student.setAge(Integer.valueOf(parser.nextText()));      }      break;     case XmlPullParser.END_TAG:      if("student".equals(nodeName)) {       studentList.add(student);      }      break;     default:      break;     }     eventType = parser.next();    }    refreshStudentList();        return true;   } catch (Exception e) {    e.printStackTrace();   }   return false;  }    private void refreshStudentList() {   llStudentList.removeAllViews();   TextView childView;   for (Student student : studentList) {    childView = new TextView(this);    childView.setTextSize(23);    childView.setTextColor(Color.BLACK);    childView.setText("　　" + student.getName() + "　　" + student.getSex() + "　　" + student.getAge());    llStudentList.addView(childView);   }  }    private boolean saveStudent2Local() {   try {    XmlSerializer serializer = Xml.newSerializer();    serializer.setOutput(new FileOutputStream(filePath), "utf-8");        serializer.startDocument("utf-8", true);    serializer.startTag(null, "infos");    for (Student stu : studentList) {     serializer.startTag(null, "student");          serializer.startTag(null, "name");     serializer.text(stu.getName());     serializer.endTag(null, "name");      serializer.startTag(null, "sex");     serializer.text(stu.getSex());     serializer.endTag(null, "sex");      serializer.startTag(null, "age");     serializer.text(String.valueOf(stu.getAge()));     serializer.endTag(null, "age");          serializer.endTag(null, "student");    }    serializer.endTag(null, "infos");    serializer.endDocument();    return true;   } catch (Exception e) {    e.printStackTrace();   }   return false;  }   private void addStudent() {   String name = etName.getText().toString();   String sex = etSex.getText().toString();   String age = etAge.getText().toString();      if(!TextUtils.isEmpty(name)     && !TextUtils.isEmpty(sex)     && !TextUtils.isEmpty(age)) {    studentList.add(new Student(name, sex, Integer.valueOf(age)));    TextView childView = new TextView(this);    childView.setTextSize(23);    childView.setTextColor(Color.BLACK);    childView.setText("　　" + name + "　　" + sex + "　　" + age);    llStudentList.addView(childView);   } else {    Toast.makeText(this, "請正確輸入", 0).show();   }  } }