【黑马Android】(03)学生管理系统/动态刷新界面

学生管理系统

<?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="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" />        <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>

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;}@Overridepublic 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";}@Overridepublic 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();}}}

动态刷新界面

<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:orientation="vertical"    tools:context=".MainActivity" >    <Button        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:onClick="onClick"        android:text="添加" />    <ScrollView        android:layout_width="fill_parent"        android:layout_height="fill_parent" >        <LinearLayout            android:id="@+id/ll"            android:layout_width="fill_parent"            android:layout_height="fill_parent"            android:orientation="vertical" >        </LinearLayout>    </ScrollView></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima28.refreshview"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.itheima28.refreshview.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>

package com.itheima28.refreshview;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.View;import android.widget.LinearLayout;import android.widget.TextView;public class MainActivity extends Activity {private LinearLayout llGroup;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);llGroup = (LinearLayout) findViewById(R.id.ll);}public void onClick(View view) {// 添加一个TextView向llGroup// 定义一个textview对象TextView tv = new TextView(this);tv.setText("张三　　　女　　　34");// 把textview对象添加到linearlayout中llGroup.addView(tv);}}