listView中继承BaseAdapter并且扩展LinearLayout

最新推荐文章于 2022-07-28 09:38:11 发布

原创最新推荐文章于 2022-07-28 09:38:11 发布 · 148 阅读

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本文介绍了一种自定义适配器的方法，用于Android应用中天气数据的展示。通过创建Weather类来封装城市、温度及天空状态等信息，并通过WeatherAdapter进行数据绑定，实现了列表视图的动态更新。

定义一个对象：

public class Weather {
  public static final int NA = -1;
  public static final int SUNNY = 0;
  public static final int OVERCAST = 1;
  public static final int RAIN = 2;

  public String city = null;
  public int temperature = 0;
  public int sky = NA;

  public Weather( String city, int temperature, int sky ) {
    this.city = city;
    this.temperature = temperature;
    this.sky = sky;
  }

  public String getCity() {
	return city;
  }

  public int getTemperature() {
	return temperature;
  }

  public int getSkyResource() {
	switch( sky ) {
	  case SUNNY:
			return R.drawable.weather_sunny;

	  case OVERCAST:
			return R.drawable.weather_overcast;

	  case RAIN:
			return R.drawable.weather_rain;
	}
	return R.drawable.unknown;
  }
}

主activity

public class CustomAdapterActivity extends ListActivity
{
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ArrayList<Weather> weatherList = new ArrayList<Weather>();
        Weather w = new Weather( "London", 17, Weather.OVERCAST );
        weatherList.add( w );
        w = new Weather( "Paris", 22, Weather.OVERCAST );
        weatherList.add( w );
        w = new Weather( "Athens", 29, Weather.SUNNY );
        weatherList.add( w );
        w = new Weather( "Stockholm", 12, Weather.RAIN );
        weatherList.add( w );
        WeatherAdapter weatherAdapter = new WeatherAdapter( 
				this,
				weatherList ); 
        setListAdapter( weatherAdapter );
    }
}

最关键的就是 WeatherAdapter

class WeatherAdapterView extends LinearLayout {        
        public static final String LOG_TAG = "WeatherAdapterView";

        public WeatherAdapterView(Context context, 
								Weather weather ) {
            super( context );

            this.setOrientation(HORIZONTAL);        
            LinearLayout.LayoutParams cityParams = 
                new LinearLayout.LayoutParams(100, LayoutParams.WRAP_CONTENT);
            cityParams.setMargins(1, 1, 1, 1);

            TextView cityControl = new TextView( context );
            cityControl.setTextAppearance( context, R.style.SpecialText );
			cityControl.setText( weather.getCity() );
            addView( cityControl, cityParams);       

            LinearLayout.LayoutParams temperatureParams = 
                new LinearLayout.LayoutParams(20, LayoutParams.WRAP_CONTENT);
            temperatureParams.setMargins(1, 1, 1, 1);

            TextView temperatureControl = new TextView(context);
            temperatureControl.setText( Integer.toString( weather.temperature ) );
            addView( temperatureControl, temperatureParams);            

            LinearLayout.LayoutParams skyParams = 
                new LinearLayout.LayoutParams(25, LayoutParams.WRAP_CONTENT);

			ImageView skyControl = new ImageView( context );
            Log.d( LOG_TAG, weather.getCity()+" -> "+weather.sky );
			skyControl.setImageResource( weather.getSkyResource() );
			addView( skyControl, skyParams );
        }
}

public class WeatherAdapter extends BaseAdapter {

    private Context context;
    private List<Weather> weatherList;

    public WeatherAdapter(Context context, List<Weather> weatherList ) { 
        this.context = context;
        this.weatherList = weatherList;
    }

    public int getCount() {                        
        return weatherList.size();
    }

    public Object getItem(int position) {     
        return weatherList.get(position);
    }

    public long getItemId(int position) {  
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) { 
        Weather weather = weatherList.get(position);
        return new WeatherAdapterView(this.context, weather );
    }

}

通过定义一个对象在这个对象中包含要显示的东西，这样就不用使用simpleAdapater了，不同的方法自己选择吧。

<?xml version="1.0" encoding="utf-8"?>  
<resources>  
    <style name="MyTheme" parent="android:Theme.Light">  
        <item name="android:listViewStyle">@style/MyListView</item>  
    </style>  

    <style name="SpecialText" parent="@android:style/TextAppearance">
        <item name="android:textSize">18sp</item>
        <item name="android:textStyle">bold</item>
        <item name="android:textColor">#008</item>
    </style>

    <style name="MyListView" parent="@android:style/Widget.ListView">  
        <item name="android:background">@color/opaque_red</item>
        <item name="android:listSelector">@drawable/z_selector_background</item>
    </style>
</resources>

别忘了在主xml中加入上面的主题。

源文件上传了这里面也使用到了selector