最终要做的项目目标：
2、编写Android清单文件AndroidManifest.xml
<?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="19" />
<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" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
3 编写布局文件activity_main.xml
<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="学生管理系统"
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="性别"
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="年龄"
android:textSize="18sp" />
<!-- 在姓名的下面 -->
<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" />
<!-- 在性别的下面 -->
<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="添加学生"
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="保存数据"
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="恢复数据"
android:textSize="20sp" />
</LinearLayout>
</LinearLayout>
4 编写Student实体
package com.itheima27.sutdentmanager.entities;
public class Student {
private String name;
private String sex;
private Integer age;
public Student() {
super();
}
public Student(String name, String sex, Integer age) {
super();
this.name = name;
this.sex = sex;
this.age = age;
}
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 + "]";
}
}
5 编写MainActivity
package com.itheima27.sutdentmanager;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlSerializer;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.ActionBarActivity;
import android.text.TextUtils;
import android.util.Xml;
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;
import com.itheima27.sutdentmanager.entities.Student;
public class MainActivity extends ActionBarActivity 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";
}
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_save:
if(studentList.size() > 0) {
//将信息写到xml文件中
if(saveStudent2Local()) {
Toast.makeText(this, "保存成功", 0).show();
} else {
Toast.makeText(this, "保存失败", 0).show();
}
} else {
Toast.makeText(this, "当前没有数据", 0).show();
}
break;
case R.id.btn_restore:
if(restoreStudentFromLocal()) {
Toast.makeText(this, "恢复成功", 0).show();
} else {
Toast.makeText(this, "恢复失败", 0).show();
}
break;
case R.id.btn_add_student:
addStudent();
break;
default:
break;
}
}
/**
* 从xml中读出Student数据
* @return
*/
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;
}
/**
* 恢复student的List列表
*/
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, "请正确输入", 0).show();
}
}
}
