android中利用實現二級聯動的效果

本篇文章實現的效果就是如圖中所圈的那樣，實現類似於HTML中的二級聯動的效果。   對於第一個選項我們讀取的是本地xml文件來填充數據的，   對於第二個選項我們讀取的是通過中央氣象台提供的API返回的xml格式的數據來填充的。   首先是主頁面排版，由於我做的是一個天氣預報的功能，所以添加了很多與本文無關的控件，在代碼注釋中寫的很清楚，大家可以直接略過。    

public class WeatherPage extends RelativeLayout{  
    private Context parentContext;  
      
    /**監聽*/  
    private MyButtonListen mylisten;  
      
    /**定義天氣對象*/  
    private GetWeatherService service;  
      
    private RelativeLayout toplayout;  
    private int toplayoutid=100;  
    private RelativeLayout centerlayout;  
    private int centerlayoutid=200;  
    private RelativeLayout footlayout;  
    private int footlayoutid=300;  
      
    /** topView*/  
    private ImageView dogpetimg;  
    private TextView titleview;  
    private ImageButton switchBtn;  
      
    /** showweatherView*/  
    private RelativeLayout showWeather;  
    private int showWeatherid=201;  
    private TextView datetext;  
      
    /** functionView*/  
    private LinearLayout functionLayout;  
    private TextView selectCitytext;  
    private Spinner selectProvince;  
    private ArrayAdapter<CharSequence> adapterProvince;  
    private Map<String,String> provincemap;  
      
    private Spinner selectCity;  
    private Map<Integer,CityWeather> citymap;  
    private ArrayAdapter<CharSequence> adapterCity;  
      
    private ImageButton okBtn;  
    private ImageButton selectBtn;  
      
    /** 本類對象的樣式 */  
    private LayoutParams lp;//准備放入ViewFlipper中，所以暫且准備一下，  
      
    public WeatherPage(Context context) {  
        super(context);  
        this.parentContext=context;  
        mylisten=new MyButtonListen();  
        service=new GetWeatherService();  
        init();  
    }  
    private void init() {  
        toplayout=new RelativeLayout(parentContext);  
        toplayout.setId(toplayoutid);  
        LayoutParams lptoplayout=new LayoutParams(-1,-2);  
        lptoplayout.setMargins(0, 20, 0, 0);  
        //添加組件  
        addTopLayout(lptoplayout);  
        addView(toplayout,lptoplayout);  
          
          
          
        centerlayout=new RelativeLayout(parentContext);  
        centerlayout.setId(centerlayoutid);  
        LayoutParams lpcenterlayout=new LayoutParams(-1,370);  
        lpcenterlayout.setMargins(0, 30, 0, 0);  
        lpcenterlayout.addRule(RelativeLayout.BELOW,toplayoutid);  
        //添加組件  
        addCenterLayout(lpcenterlayout);  
        addView(centerlayout,lpcenterlayout);  
          
          
        footlayout=new RelativeLayout(parentContext);  
        footlayout.setBackgroundColor(Color.RED);  
        footlayout.setId(footlayoutid);  
        LayoutParams lpfootlayout=new LayoutParams(-1,-2);  
        lpfootlayout.setMargins(20, 10, 20, 0);  
        //添加組件  
        addFootLayout(lpfootlayout);  
        lpfootlayout.addRule(RelativeLayout.BELOW,centerlayoutid);  
        addView(footlayout,lpfootlayout);  
          
    }  
      
    public LayoutParams getLp() {  
        this.lp=new LayoutParams(-1,-1);  
        return lp;  
    }  
      
    public void addTopLayout(LayoutParams lp){  
        dogpetimg=new ImageView(parentContext);  
        LayoutParams lpdogpetimg=new LayoutParams(60,60);  
        lpdogpetimg.addRule(RelativeLayout.ALIGN_PARENT_LEFT);  
        dogpetimg.setBackgroundResource(R.drawable.dogsmall);  
        lpdogpetimg.setMargins(10, 0, 0, 0);  
          
        titleview=new TextView(parentContext);  
        titleview.setText("天氣預報");  
        titleview.setTextColor(Color.BLUE);  
        LayoutParams lptitleview=new LayoutParams(-2,-2);  
        lptitleview.addRule(RelativeLayout.CENTER_HORIZONTAL);  
          
        switchBtn=new ImageButton(parentContext);  
        //先進行判斷，判斷原來的開關狀態，然後再添加背景圖片，標記位設置在helper類中。  
        switchBtn.setBackgroundResource(R.drawable.start);  
        LayoutParams lpswitchBtn=new LayoutParams(40,40);  
        lpswitchBtn.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);  
        lpswitchBtn.setMargins(0, 20, 50, 0);  
        //添加監聽  
        switchBtn.setOnClickListener(mylisten);  
  
        toplayout.addView(dogpetimg,lpdogpetimg);  
        toplayout.addView(titleview, lptitleview);  
        toplayout.addView(switchBtn,lpswitchBtn);  
          
    }  
  
    public void addCenterLayout(LayoutParams lp) {  
        showWeather=new RelativeLayout(parentContext);  
        showWeather.setId(showWeatherid);  
        LayoutParams lpshowWeather=new LayoutParams(400,300);  
        lpshowWeather.addRule(RelativeLayout.CENTER_HORIZONTAL);  
        showWeather.setBackgroundColor(Color.CYAN);  
          
        datetext=new TextView(parentContext);  
        LayoutParams lpdatetext=new LayoutParams(400,-2);  
        lpdatetext.addRule(RelativeLayout.CENTER_HORIZONTAL);  
        lpdatetext.addRule(RelativeLayout.BELOW,showWeatherid);  
        lpdatetext.setMargins(20, 20, 20, 0);  
//      datetext.setBackgroundColor(Color.LTGRAY);  
        datetext.setText(TimeHelper.getDateInChina());  
        datetext.setGravity(Gravity.CENTER_HORIZONTAL);  
          
        centerlayout.addView(showWeather, lpshowWeather);  
        centerlayout.addView(datetext, lpdatetext);  
    }  
  
    public void addFootLayout(LayoutParams lp) {  
          
        functionLayout=new LinearLayout(parentContext);  
        functionLayout.setId(301);  
//      functionLayout.setBackgroundColor(Color.YELLOW);  
        LayoutParams lpfunctionLayout=new LayoutParams(-2,-2);  
        lpfunctionLayout.addRule(RelativeLayout.ALIGN_PARENT_TOP);  
        lpfunctionLayout.addRule(RelativeLayout.CENTER_HORIZONTAL);  
        lpfunctionLayout.setMargins(10, 0, 0, 0);  
          
        //添加顯示文字  
        selectCitytext=new TextView(parentContext);  
        selectCitytext.setText("請設置：");  
          
        //添加選擇省  
        selectProvince=new Spinner(parentContext);  
        selectProvince.setPrompt("請選擇省份");  
        //獲取省份Map<序列號,省份對象>  
        provincemap=service.getProvinceMap();  
        String[] provinceData=service.getProvinceArray(provincemap);  
        //定義下拉列表適配器，用於填充內容  
        adapterProvince=null;  
        adapterProvince=new ArrayAdapter<CharSequence>(parentContext,android.R.layout.simple_spinner_item,provinceData);  
        //設置列表顯示風格  
        adapterProvince.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);  
        selectProvince.setAdapter(adapterProvince);  
        selectProvince.setOnItemSelectedListener(new MyOnItemSelectedListen());  
          
        //添加選擇市  
        selectCity=new Spinner(parentContext);  
        selectCity.setPrompt("請選擇城市");  
        //定義下拉列表適配器，用於填充內容  
        adapterCity=null;  
        //設置列表顯示風格  
        selectCity.setAdapter(adapterCity);  
          
        functionLayout.addView(selectCitytext);  
        functionLayout.addView(selectProvince);  
        functionLayout.addView(selectCity);  
          
        okBtn=new ImageButton(parentContext);  
        okBtn.setBackgroundResource(R.drawable.okbtn);//給綁定按鈕添加背景圖片  
        LayoutParams lpokBtn=new LayoutParams(-2,-2);  
        lpokBtn.setMargins(20, 20, 0, 0);  
        lpokBtn.addRule(RelativeLayout.ALIGN_PARENT_LEFT);  
        lpokBtn.addRule(RelativeLayout.BELOW,301);  
        //添加監聽  
        okBtn.setOnClickListener(mylisten);  
          
        selectBtn=new ImageButton(parentContext);  
        selectBtn.setBackgroundResource(R.drawable.selectbn);//給查詢按鈕添加背景圖片  
        LayoutParams lpselectBtn=new LayoutParams(-2,-2);  
        lpselectBtn.setMargins(0, 20, 20, 0);  
        lpselectBtn.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);  
        lpselectBtn.addRule(RelativeLayout.BELOW,301);  
        //添加監聽  
        selectBtn.setOnClickListener(mylisten);  
          
        footlayout.addView(functionLayout,lpfunctionLayout);  
        footlayout.addView(okBtn, lpokBtn);  
        footlayout.addView(selectBtn, lpselectBtn);  
    }  
  
    /** 
     * 監聽各種按鈕的點擊事件 
     * @author Administrator 
     */  
    class MyButtonListen implements OnClickListener{  
        @Override  
        public void onClick(View v) {  
            // TODO Auto-generated method stub  
            if(v==switchBtn){  
                //關閉外顯示功能  
                System.out.println("點擊外顯示開關");  
                //換色  
                switchBtn.setBackgroundResource(R.drawable.end);  
            }else if(v==okBtn){  
                //確定，對城市進行保存。寫入小型數據庫  
                System.out.println("點擊保存開關");  
                  
            }else if(v==selectBtn){  
                //確定，對城市進行查詢，不保存  
                System.out.println("點擊查詢開關");  
            }else{  
                  
                Log.e("tag", "問題，輸入的值不對");  
            }  
        }  
    }  
    /** 
     * 監聽第一個選項的選擇，當地一個選項框被選擇數據的時候出發該類中的事件 
     * @author Administrator 
     */  
    class MyOnItemSelectedListen implements OnItemSelectedListener{  
  
        @Override  
        public void onItemSelected(AdapterView<?> item, View view,  
                int position, long arg3) {  
              
            String provincename = item.getAdapter().getItem(position).toString();  
            System.out.println(provincename);  
            String pinyin = provincemap.get(provincename);  
            Map<String, String> cityIdMap = service.getCityMap(pinyin);  
            String[] cityArray = service.getCityArray(cityIdMap);  
              
            adapterCity=new ArrayAdapter<CharSequence>(parentContext,android.R.layout.simple_spinner_item,cityArray);  
            //設置列表顯示風格  
            adapterCity.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);  
            selectCity.setAdapter(adapterCity);  
        }  
  
        @Override  
        public void onNothingSelected(AdapterView<?> arg0) {  
            // TODO Auto-generated method stub  
              
        }  
    }  
}