Android使用SAX解析XML(3)

主界面MainActivity.java：

package com.hzhi.my_sax;

import java.util.ArrayList;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;

public class MainActivity extends Activity implements OnItemSelectedListener{
	
	public static final String str_school = "School";
	public static final String str_major = "Major";
	public static final String str_clas = "Class";
	
	// 控件变量
	public Spinner spn_school;
	public Spinner spn_major;
	public Spinner spn_clas;
	public infor m_infor;
	
	// 适配器容器
	public ArrayList<school> arr_school = new ArrayList<school>();
	public ArrayList<major> arr_major = new ArrayList<major>();
	public ArrayList<clas> arr_clas = new ArrayList<clas>();
	
	// 选择的项目编号
	public int pos_school;
	public int pos_major;
	public int pos_class;
	
	// 选择班级次数
	public int c_num = 0;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		// 获得控件
		get_con();
		
		// 设置适配器
        ArrayAdapter<school> ada_school = new ArrayAdapter<school>(this, 
				android.R.layout.simple_spinner_item, arr_school);
        ada_school.setDropDownViewResource(
				android.R.layout.simple_spinner_dropdown_item);
		spn_school.setAdapter(ada_school);
		
        ArrayAdapter<major> ada_major = new ArrayAdapter<major>(this, 
				android.R.layout.simple_spinner_item, arr_major);
        ada_major.setDropDownViewResource(
				android.R.layout.simple_spinner_dropdown_item);
		spn_major.setAdapter(ada_major);
		
        ArrayAdapter<clas> ada_clas = new ArrayAdapter<clas>(this, 
				android.R.layout.simple_spinner_item, arr_clas);
        ada_clas.setDropDownViewResource(
				android.R.layout.simple_spinner_dropdown_item);
		spn_clas.setAdapter(ada_clas);
		
		// 设置监听器
		spn_school.setOnItemSelectedListener(this);
		spn_major.setOnItemSelectedListener(this);
		spn_clas.setOnItemSelectedListener(this);		
		
		m_infor = new infor();
		init();
		
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
	
	// 获得控件
	public void get_con(){
		
		spn_school = (Spinner) findViewById(R.id.spn_school);
		spn_major = (Spinner) findViewById(R.id.spn_major);
		spn_clas = (Spinner) findViewById(R.id.spn_class);
		
	}
	
	// 选择学院
	public void do_school_select() {
		
		//清除数据集
		arr_major.clear();
		arr_clas.clear();
		//设置数据集
		arr_major.addAll(m_infor.get_schools().get(pos_school).get_majors());
		arr_clas.addAll(
				m_infor.get_schools().get(pos_school).get_majors().get(0).get_clases()); 
		//通知数据集改变		
		((ArrayAdapter)this.spn_major.getAdapter()).notifyDataSetChanged();
		((ArrayAdapter)this.spn_clas.getAdapter()).notifyDataSetChanged();
		//初始化设置选择项
		this.spn_major.setSelection(0);
		this.spn_clas.setSelection(0);
		
		c_num = 0;
		
	}
	
	// 选择专业
	public void do_major_select() {
		
		//清除数据集
		arr_clas.clear();
		//设置数据集
		arr_clas.addAll(
				m_infor.get_schools().get(pos_school).get_majors().get(pos_major).get_clases()); 
		//通知数据集改变		
		((ArrayAdapter)spn_clas.getAdapter()).notifyDataSetChanged();
		//初始化设置选择项
		spn_clas.setSelection(0);
		
		c_num = 0;
		
	}
	
	// 选择班级
	public void do_class_select(){

		if (c_num>0)
		{
			school b_school = m_infor.get_schools().get(pos_school);
			major b_major = b_school.get_majors().get(pos_major);
			clas b_clas = b_major.get_clases().get(pos_class);
		
			Intent i = new Intent(this, DetailActivity.class);
			i.putExtra(str_school, b_school);
			i.putExtra(str_major, b_major);
			i.putExtra(str_clas, b_clas);
			this.startActivity(i);
		}
		
		c_num++;
		
	}
	
	@Override
	public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
		// TODO Auto-generated method stub
		
		switch(parent.getId()) {
			case R.id.spn_school: {
				pos_school = pos;
				do_school_select();
				break;
			}
			case R.id.spn_major: {
				pos_major = pos;
				do_major_select();
				break;
			}
			case R.id.spn_class: {
				pos_class = pos;
				do_class_select();
				break;
			}			
		}
	}

	@Override
	public void onNothingSelected(AdapterView<?> arg0) {
		// TODO Auto-generated method stub
		
	}
	
	// 清除数据集
	public void clear_all_dataset(){
		
		arr_school.clear();
		arr_major.clear();
		arr_clas.clear();
		
	}
	
	// 通知所有数据集已经改变
	public void notify_all_dataset(){
		((ArrayAdapter) spn_school.getAdapter()).notifyDataSetChanged();
		((ArrayAdapter) spn_major.getAdapter()).notifyDataSetChanged();
		((ArrayAdapter) spn_clas.getAdapter()).notifyDataSetChanged();
	}
	
	// 设置数据集
	public void add_all_dataset(){
		
		arr_school.addAll(m_infor.get_schools());
		arr_major.addAll(m_infor.get_schools().get(0).get_majors());
		arr_clas.addAll(m_infor.get_schools().get(0).get_majors().
				get(0).get_clases());
		
	}
	
	// 初始化界面
	public void init(){
		
		super.onStart();
		util.get_ins().parse(
				getResources().openRawResource(R.raw.infor),m_infor);
		
		// 清除数据集
		clear_all_dataset();
		// 设置数据集
		add_all_dataset();
		// 通知数据集改变
		notify_all_dataset();
		
		
	}

}

最重要的语句是init()函数里面的

util.get_ins().parse(getResources().openRawResource(R.raw.infor),m_infor);

这条语句开始了解析infor.xml文件的过程，并将解析的结果放在变量m_infor里面。