学习Android Apidemo从这开始

package com.study.android.apis; import java.text.Collator; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.ListActivity; import android.content.Intent; import android.content.pm.PackageManager; import android.content.pm.ResolveInfo; import android.os.Bundle; import android.view.View; import android.widget.ListView; import android.widget.SimpleAdapter; public class ApiStudy extends ListActivity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Intent intent = getIntent(); String path = intent.getStringExtra("com.study.android.apis.Path"); if (path == null) { path = ""; } setListAdapter(new SimpleAdapter(this, getData(path), android.R.layout.simple_list_item_1, new String[] { "title" }, new int[] { android.R.id.text1 })); getListView().setTextFilterEnabled(true); } protected List getData(String prefix) { List<Map> myData = new ArrayList<Map>(); Intent mainIntent = new Intent(Intent.ACTION_MAIN, null); mainIntent.addCategory(Intent.CATEGORY_SAMPLE_CODE); PackageManager pm = getPackageManager(); List<ResolveInfo> list = pm.queryIntentActivities(mainIntent, 0); if (null == list) return myData; String[] prefixPath; if (prefix.equals("")) { prefixPath = null; } else { prefixPath = prefix.split("/"); } int len = list.size(); Map<String, Boolean> entries = new HashMap<String, Boolean>(); for (int i = 0; i < len; i++) { ResolveInfo info = list.get(i); CharSequence labelSeq = info.loadLabel(pm); String label = labelSeq != null ? labelSeq.toString() : info.activityInfo.name; if (prefix.length() == 0 || label.startsWith(prefix)) { String[] labelPath = label.split("/"); String nextLabel = prefixPath == null ? labelPath[0] : labelPath[prefixPath.length]; if ((prefixPath != null ? prefixPath.length : 0) == labelPath.length - 1) { addItem(myData, nextLabel, activityIntent( info.activityInfo.applicationInfo.packageName, info.activityInfo.name)); } else { if (entries.get(nextLabel) == null) { addItem(myData, nextLabel, browseIntent(prefix.equals("") ? nextLabel : prefix + "/" + nextLabel)); entries.put(nextLabel, true); } } } } Collections.sort(myData, sDisplayNameComparator); return myData; } private final static Comparator<Map> sDisplayNameComparator = new Comparator<Map>() { private final Collator collator = Collator.getInstance(); public int compare(Map map1, Map map2) { return collator.compare(map1.get("title"), map2.get("title")); } }; protected Intent activityIntent(String pkg, String componentName) { Intent result = new Intent(); result.setClassName(pkg, componentName); return result; } protected Intent browseIntent(String path) { Intent result = new Intent(); result.setClass(this, ApiStudy.class); result.putExtra("com.study.android.apis.Path", path); return result; } protected void addItem(List<Map> data, String name, Intent intent) { Map<String, Object> temp = new HashMap<String, Object>(); temp.put("title", name); temp.put("intent", intent); data.add(temp); } @Override protected void onListItemClick(ListView l, View v, int position, long id) { Map map = (Map) l.getItemAtPosition(position); Intent intent = (Intent) map.get("intent"); startActivity(intent); } }