android中利用实现二级联动的效果
本篇文章实现的效果就是如图中所圈的那样，实现类似于HTML中的二级联动的效果。对于第一个选项我们读取的是本地xml文件来填充数据的，
对于第二个选项我们读取的是通过中央气象台提供的API返回的xml格式的数据来填充的。
首先是主页面排版，由于我做的是一个天气预报的功能，所以添加了很多与本文无关的控件，在代码注释中写的很清楚，大家可以直接略过。
public class WeatherPage extends RelativeLayout{
private Context parentContext;
/**监听*/
private MyButtonListen mylisten;
/**定义天气对象*/
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;
/** 本类对象的样式 */
private LayoutParams lp;//准备放入ViewFlipper中，所以暂且准备一下，
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);
//添加组件
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);
//添加组件
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);
//添加组件
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("天气预报");
titleview.setTextColor(Color.BLUE);
LayoutParams lptitleview=new LayoutParams(-2,-2);
lptitleview.addRule(RelativeLayout.CENTER_HORIZONTAL);
switchBtn=new ImageButton(parentContext);
//先进行判断，判断原来的开关状态，然后再添加背景图片，标记位设置在helper类中。
switchBtn.setBackgroundResource(R.drawable.start);
LayoutParams lpswitchBtn=new LayoutParams(40,40);
lpswitchBtn.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
lpswitchBtn.setMargins(0, 20, 50, 0);
//添加监听
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);
//添加显示文字
selectCitytext=new TextView(parentContext);
selectCitytext.setText("请设置：");
//添加选择省
selectProvince=new Spinner(parentContext);
selectProvince.setPrompt("请选择省份");
//获取省份Map<序列号,省份对象>
provincemap=service.getProvinceMap();
String[] provinceData=service.getProvinceArray(provincemap);
//定义下拉列表适配器，用于填充内容
adapterProvince=null;
adapterProvince=new ArrayAdapter<CharSequence>(parentContext,android.R.layout.易做图_spinner_item,provinceData);
//设置列表显示风格
adapterProvince.setDropDownViewResource(android.R.layout.易做图_spinner_dropdown_item);
selectProvince.setAdapter(adapterProvince);
selectProvince.setOnItemSelectedListener(new MyOnItemSelectedListen());
//添加选择市
selectCity=new Spinner(parentContext);
selectCity.setPrompt("请选择城市");
//定义下拉列表适配器，用于填充内容
adapterCity=null;
//设置列表显示风格
selectCity.setAdapter(adapterCity);
functionLayout.addView(selectCitytext);
functionLayout.addView(selectProvince);
functionLayout.addView(selectCity);
okBtn=new ImageButton(parentContext);
okBtn.setBackgroundResource(R.drawable.okbtn);//给绑定按钮添加背景图片
LayoutParams lpokBtn=new LayoutParams(-2,-2);
lpokBtn.setMargins(20, 20, 0, 0);
lpokBtn.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
lpokBtn.addRule(RelativeLayout.BELOW,301);
//添加监听
okBtn.setOnClickListener(mylisten);
selectBtn=new ImageButton(parentContext);
selectBtn.setBackgroundResource(R.drawable.selectbn);//补充：移动开发 , Android ,
