简单的学生管理系统

一,主要功能：

　　1，添加学生信息；

　　2，添加的学生信息显示在线型布局中；

　　3，把学生信息保存在xml文件中；

　　4，把保存在mxl中的学生信息取出来解析显示在界面；

二,主要知识点:

　　1，layout_weight的使用；

　　2，pull解析xml文件，xml序列化；

　　3，保存数据到sd卡；

　　4，动态添加控件刷新界面；

三，界面原型如下图：

四，代码展示：

　　1，界面xml文件，activity_main.xml

　　2，定义实体类，Student.java

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 + "]";    }}

　　3,主界面activity,MainActivity.java

public class MainActivity extends Activity implements OnClickListener {    private EditText etName;    private EditText etSex;    private EditText etAge;    private LinearLayout llStudentList;    private List
      
        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
       
        ();        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;        }    }        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, "请正确输入", 0).show();        }    }}
       
      

 

通过以上步骤基本实现功能，不过还有需要完善的地方，比如年龄校验等